BirdLife International - Manuals for Monitoring by BirdLife International

This manual was produced within the framework of the Alcyon project financed by the MAVA Foundation (www.fondationmava.org). It was coordinated by the Fondation Internationale du Banc d'Arguin (FIBA) until December 2014 and from then onwards by BirdLife International (BLI).

The Authors Jan Veen and Wim Mullié, Veda Consultancy have realized this document from the Manual of Wetlands International (Veen, J., Peeters, J., Mullié, W.C. 2004. Manual for monitoring seabird colonies in West Africa. Wetlands International, Wageningen, The Netherlands).

Credits: Coordination and Review: Justine Dossa, Julien Semelin Lay-out and illustrations: By Reg’ - www.designbyreg.dphoto.com Printed in Dakar - January 2015 The opinions expressed in this manual are those of the authors and do not necessarily reflect those of the FIBA, BLI, MAVA or of the Alcyon project management.

MANUAL FOR MONITORING BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

Jan Veen & Wim C. Mullié

MANUAL FOR MONITORING

CONTENTS 1. INTRODUCTION Why this manual? Breeding colonies Seabirds as indicators of fish abundance

4 4 6 8

2. TAKE CARE IN A BREEDING COLONY

3. ESTIMATING THE SIZE OF THE BREEDING POPULATION

Estimating breeding pairs (all species) Counting Slender-billed Gulls Counting Grey-headed Gulls Counting Royal Terns Counting Caspian terns Making monthly counts

16 18 20 26 32 34

4. MEASURING CLUTCH SIZE AND EGG SIZE Clutch size Egg size

35 36 36

5. MEASURING CHICK CONDITION

Condition index and condition graphs Catching, measuring and weighing chicks

38 40

6. MEASURING BREEDING SUCCESS

Measuring breeding success Measuring hatching success Measuring fledging success

44 46 48

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

7. RINGING AND CATCHING CHICKS Why ringing birds? Ringing in Africa Types of rings Catching birds for ringing Handling birds correctly The actual ringing Ring administration

51 51 52 53 54 58 62 65

8. COLLECTING PELLETS AND FAECES

9. PLANNING AND ADMINISTRATION

The planning table Administration

10. MAINTENANCE OF EQUIPMENT Electronic equipment Binoculars and telescopes

70 72

74 74 75

11. REFERENCES

12. APPENDICES

1. Checklist with materials 2. Form for measuring clutch size 3. Form for measuring egg size 4. Form for measuring chick condition 5. Condition graphs 6. Form for ringing

77 78 80 82 84 86

MANUAL FOR MONITORING

1. INTRODUCTION WHY THIS MANUAL? Oceanic currents along the Atlantic coast of Northwest Africa give rise to upwellings, which bring cold and nutrient-rich water to the surface. As a result, the area is extremely rich in fish.

Figure 1.1. Fishing vessels and birds exploiting fish resources

Traditionally, this resource is exploited by artisanal fishermen. During the past two decades, the intensity of artisanal as well as industrial coastal fishing has enormously increased. There is great regional and international concern about over-fishing, which negatively affects national economies and nature values (Fig. 1.1). Hundreds of thousands of fish-eating seabirds, the globally threatened Monk Seal and 37 species of cetaceans (whales, dolphins and porpoises) also depend on the abundant fish resources. To what extent human fishing activities may influence their survival is unknown. This manual was made in the framework of the Alcyon project, which aims at the protection of seabirds in West Africa by identifying key sites for reproduction, the so-called Marine Protected Areas (IBAs). The focus of the project is on obtaining information on the numbers and the distribution of these birds in order to protect the breeding islands, which are scarcely available and in many cases threatened. Besides, data will be obtained, which make it possible to use the birds as indicators of the health of their environment, especially in relation to food availability.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

The final goal of the project is to implement a monitoring program, which provides long-term data on the development of the populations of the colonial breeding birds. Determining population changes should be the first step in identifying factors, which pose a threat to these birds. Such factors can be manifold, such as food shortage, habitat destruction, chemical pollution, human disturbance and others. The final goal of the project is, that site managers use the monitoring results for the management of the breeding islands: to initiate management measures and to evaluate actions being taken. This manual is primarily made to assist fieldworkers, who are involved in monitoring activities in the seabird breeding colonies. It mainly gives guidelines on how to correctly obtain information in a standardized manner, which can later be used to analyse the health of colonies in the West-African region. It also helps users to know how to behave while working in a seabird breeding colony and how to maintain the equipment that is used during the monitoring activities. It does not give guidelines on how to analyze the data. With respect to the latter the reader is referred to the â&#x20AC;&#x153;Manual for monitoring seabird colonies in West Africa.â&#x20AC;? (Veen et al. 2004) which provides much more detailed information and guidance for the analysis of the data.

MANUAL FOR MONITORING

BREEDING COLONIES The Sahelian Upwelling Marine Region borders the coasts of Morocco, Mauritania, Senegal, The Gambia, Guinea Bissau and Guinea. Figure 1.2 gives the position of the upwelling zone (insert) and of the most important colony areas. Islands suitable for breeding are few and mainly available in the southern part of the upwelling area, and on the Cape Verde and Canary Islands. There is great variation in protective status of the different areas as well as in our knowledge regarding numbers and distribution of the different bird species.

Figure 1.2 Main breeding colonies

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

In the period 1998-2013 the various islands have been visited at least once, resulting in a list of 18 ground-nesting colony breeding species. Table 1.1 gives an overview of the species with an indication of numbers and breeding distribution. Table 1.2 gives an overview of breeding periods. Some of the species listed are of special importance, because they are endemic to the region, such as the African sub-species of the Royal Tern Sterna maxima albididorsalis. The sub-species of the Eurasian Spoonbill Platalea leucorodia balsaci and the Grey heron Ardea cinerea monicae are endemic to the Banc d’Arguin, Mauritania. The populations of these species are small and vulnerable. Table 1.1. Breeding numbers (pairs) and distribution of ground nesting colonial breeding birds along the coast of West Africa. Species Brown Booby White-breasted Cormorant Long-tailed Cormorant Great White Pelican Western Reef Heron Grey Heron Eurasian Spoonbill Greater Flamingo Lesser Flamingo Grey-headed Gull Slender-billed Gull Kelp Gull Gull-billed Tern Caspian Tern Royal Tern Common Tern Bridled Tern Little Tern

Population 2.000 12.000 2.000 20.000 2.000 3.000 1.500 20.000 7.500 10.000 7.500 20 1.500 18.000 95.000 150 650 100

• • • • • • • • • • • • • • • • •

• • • •

• • o • • • • o •

M = Mauritania, S = Senegal, G =The Gambia, GB = Guinea Bissau, GC = Guinea. • = regular breeding, o = incidental breeding. Data from Veen (unpubl.) and Wetlands International 2006.

•

• • •

• •

•

• •

• • • o

G • • • • •

• •

MANUAL FOR MONITORING

Table 1.2. Breeding periods (by month) of ground nesting colonial breeding birds along the coast of West Africa. The second column indicates the country on which data are based Species Brown Booby White-breasted Cormorant Long-tailed Cormorant Great White Pelican Western Reef Heron Grey Heron Eurasian Spoonbill Greater Flamingo Lesser Flamingo Grey-headed Gull Slender-billed Gull Kelp Gull Gull-billed Tern Caspian Tern Royal Tern Common Tern Bridled Tern Little Tern

G M M M M M M M M S S S M S S S M M

J • • • • •

•

F M A • • • • • • • • • • • • • •

•

• • •

•

• •

M J • • •

•

• •

• • • • • • • • •

J A S O N • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •

D • • • •

•

M = Mauritania, S = Senegal, G = Guinea.

SEABIRDS AS INDICATORS OF FISH ABUNDANCE Seabirds can be good indicators of fish resources. This is especially the case in the breeding period, when food needs to be plentiful. This is because: (1) the female needs to lay eggs, (2) only half of the time can be spent foraging because one birds needs to incubate eggs or protect the chick and (3) chicks need to be fed. Several so-called breeding parameters are related to food availability, i.e. they can give us information about the amount of food that the birds can find. For instance, when food is plentiful, more birds will be able to reproduce. So the number of breeding birds will increase. The breeding birds will also be able to lay more (or larger) eggs and chicks can be properly fed, so a relatively large number of chicks may survive. When food is scarce the opposite will be the case (figure 1.3).

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

Breeding success may thus give information about food availability. However, when food gets short, it is also interesting to know, which fish species is in short supply. This means that, concurrently with the data on breeding parameters data on the diet need to be collected.

Food availability

Adult condition

Number and volume of eggs

Chick condition

Reproductive success

Survival after fledging Figure 1.3. Breeding parameters and food availability

MANUAL FOR MONITORING

This manual deals with methods and techniques, needed for determining: o breeding population size o clutch size o egg dimensions o chick condition o diet composition Related techniques such as bird ringing are dealt with as well. The interventions described in this manual require technical and scientific skills. Only personal skills in the area may conduct such activities. Before any intervention, obtain the necessary approvals from regulatory authorities.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

2. TAKE CARE IN A BREEDING COLONY When you want to do observations in a breeding colony you have to approach the breeding birds and, in many cases, you have to enter the colony area. This will disturb the birds, which involves certain risks for the eggs and chicks. When doing your work, always remember that you collect information to be used for nature conservation purposes. Always keep in mind that the welfare of the birds comes first. This means that you always carefully judge the situation in order to keep disturbance to a minimum. Special attention must be given to the following: 1. Always minimise the time spent in the colony It is of crucial importance to plan your activities in advance. Know what to do and divide tasks between group members. A well-trained team can work quickly. 2. Concentrate disturbance in one place When working in a group, you should stay together and concentrate disturbance in one place.

Figure 2.1. Observers watch a colony from a distance

MANUAL FOR MONITORING

3. Avoid that eggs and chicks are exposed to high temperatures In tropical regions, embryos in eggs and chicks may easily die when they are exposed to the heat of the sun for a long period. Therefore, only enter the colonies in the early morning and late afternoon, when temperatures are lower. In West Africa, as a rule, colonies should only be entered before 10.00 hrs. and after 17.00 hrs. But even so it is necessary to keep an eye on the situation. At 7.00 hrs. in the morning you can stay longer in a particular place than at 10.00 hrs. On cloudy days slight deviations to this schedule might be possible. 4. Do not disturb settling birds In seabird colonies egg-laying is often highly synchronised and all pairs in a particular part of the colony may lay their eggs in a period of only a few days. In the egg-laying period disturbance may cause the birds to desert their clutches. Therefore, avoid disturbing settling birds. Do not count nests, but make an estimate of the number of pairs present from a safe distance with binoculars. You can enter the colony and count the nests at a later stage of the breeding cycle. 5. Do not disturb small chicks Chicks of the Caspian Tern, Royal Tern, and Slender-billed Gull usually stay in the nest for about a week. When getting older, they become more mobile and voluntarily move around in the vicinity of the nest. As a rule, chicks of the Caspian Tern and Slender-billed Gull return to the nest to be fed, but Royal Tern chicks gradually move away from the nesting area and concentrate in groups, also called crĂ¨ches, on the beach where they are fed by their parents. In reaction to human disturbance, small chicks may leave the nest walking away from the human intruder. Such chicks may have difficulties in finding their way back to the nest. This is especially a problem in the dense colonies of the Royal Tern where breeding adults behave aggressively towards any chick apart from their own offspring passing the territory. This may cause serious injury or even death of such chicks. Therefore, avoid disturbing Royal Tern colonies with small chicks and always keep an eye on how chicks (small and larger ones of all species) react to your presence. Chicks should never end up in the middle of a dense colony far away from their place of birth.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

6. Do not chase large chicks over long distances Medium-sized and large chicks that have left the colony area may concentrate along the beach. When walking along the beach, especially at high tide, such chicks tend to run away from a human observer following the coastline. Avoid chasing such chicks over long distances. They may get exhausted and overheated. Leave the beach for a while by moving inland, thus giving way to the chicks and allowing them to return.

Figure 2.2. Do not chase chicks along water edge

7. Avoid being the cause of egg predation Grey-headed Gulls and Slender-billed Gulls are opportunistic foragers, with eggs forming part of their diet. As a rule, only a small number of gulls tend to steal eggs from temporarily unattended nests of other gulls (including their own species) and terns. However, certain gulls may specialise in robbing eggs in parts of the colony disturbed by human observers. Always keep an eye on (potential) predators, which try to land in your working area. The problem can be partly solved by staying together and thus minimising the area of disturbance (see above under 2). Sometimes it may be necessary to leave the area and choose another part of the colony for doing your research. Royal Tern

MANUAL FOR MONITORING

colonies situated close to Slender-billed Gull colonies tend to be more vulnerable. Therefore, it is important to have knowledge of the location of all colonies before starting research at a particular place.

Figure 2.3. Egg predation

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

3. ESTIMATING THE SIZE OF THE BREEDING POPULATION The size of the breeding population is expressed as the number of pairs breeding. Determining breeding population size is the first thing to do when starting a monitoring program. The method to be used depends on: o the species involved o the size, location and accessibility of the colony o the phase of the breeding cycle o the number of persons available to do observations o the level of experience of the observers o whether you visit the area only once or at regular intervals.

The methods vary from a rough estimate of the "total number of breeding birds present" to an "exact count of the number of occupied nests". The first method is used when circumstances do not allow carrying out a more precise count, e.g. bad weather or a lack of time. An estimate will also be made when the colony area is visited only once and when eggs, chicks and fledglings are present all at the same time. In the framework of the present monitoring program it is envisaged to visit all potential breeding sites, check the active colonies once a month throughout the breeding season and to count only nests with eggs. In order not to miss breeding birds and to notice breeding failure (e.g. due to high tides, predation or egg collection) it is important not to miss a single month. The frequency is based on the fact that all species included in the monitoring program have an incubation period, which is less than 30 days on average. How to work with monthly counts is explained later.

MANUAL FOR MONITORING

ESTIMATING BREEDING PAIRS (ALL SPECIES) There may be several reasons for estimating the number of breeding birds instead of making accurate counts of nests with eggs and/or chicks. As a rule, an estimate concentrates on the number of adult birds present in the colony. An easy method for making an estimate is the "block method". The method involves counting or estimating a "block" of birds within a group. Depending on the group size, the block can include 10, 100, or 1000 birds. The "block" is then used as a model to measure the remainder of the flock (figure 3.1.).

number off b birds number o irds counted co unted

1100 00

Figure 3.1. Block method

The number of adult birds present is not necessarily the same as the number of breeding pairs. There may be two partners present near a nest or there may be a group of roosting birds in or near the colony. In all cases, try to obtain information on the proportion of birds not involved in incubation and subtract them from your total. It is much easier to use this method in the period when there are eggs than in the chick period. In all cases: describe what you have done and mention all categories of birds that have been counted.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

PROCEDURE FOR ESTIMATING BREEDING PAIRS 1. Approach the colony without disturbing the birds 2. Count/estimate numbers using the block method. Binoculars or telescopes may be needed depending on the distance to the colony. 3. Compare results of different observers. 4. Count/estimate once more, if necessary. 5. Discuss situation and decide on the final number. 6. Make notes on the phase of breeding (part of population with eggs, chicks and fledglings; occurrence of non-breeding birds).

Materials needed: 1. Binoculars and/or telescope 2. Notebook and pen(cil)s 3. Tally counter

MANUAL FOR MONITORING

COUNTING SLENDER-BILLED GULLS Slender-billed Gull colonies are usually small, varying in size from a dozen to a few hundred nests (figure 3.2). In most cases, the nests of Slender-billed Gulls can easily be counted by one person slowly walking through the colony using natural markings, such as vegetation, to separate parts of the colony already done from those still to be counted. When dealing with a larger colony, it may be useful to involve two to four persons and it may also be necessary to introduce some extra markings in addition to natural ones (stick, drawing line in sand). It is handy to use a tally counter, but set it at zero when you start (figure 3.3) and check it regularly while you advance. Past experience has shown that the cheaper tally counters are not always reliable. Therefore, try to use â&#x20AC;&#x153;old fashionedâ&#x20AC;? mechanical counters of a reliable brand. If the colony is counted only once in a breeding season, all occupied nests are counted (with eggs or chicks and even the nests from which the chicks recently left). If counts are carried out each month, only nests with eggs are included.

Figure 3.2. Slender-billed Gull colony

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

Figure 3.3. Tally counter

PROCEDURE FOR COUNTING SLENDER-BILLED GULL COLONIES 1. Watch the colony from a safe distance and divide labour between persons. 2. Collect material for marking (if needed). 3. Count all nests. 4. Write down results, including information on phase of breeding, traces of predation, etc. Materials needed: 1. Binoculars. 2. Ropes or large sticks (in case of larger colonies) to trace lines dividing nests. 3. Notebook and pen(cil)s. 4. Tally counter.

MANUAL FOR MONITORING

COUNTING GREY-HEADED GULLS Counting all nests Grey-headed Gulls breed in colonies sizing from a few to many thousands of pairs. Nests are made in areas with low, sometimes dense vegetation. Inter-nest distances vary between 1 and more than 10 meters (figure 3.4). Large breeding colonies may spread over a very large area, and counting such colonies is complicated and time-consuming.

Figure 3.4. Grey-headed Gull colony

Small concentrations of nests (up to a hundred) can usually be counted by one or two persons traversing the area as described for the Slenderbilled Gull. However, in most cases, Grey-headed Gull nests should be counted by a group of persons (preferably 4 or more) as shown in figure 3.5.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

2nd p pass ass

St Starting arting lline ine

1st p pass ass

4m 4m

Counter Co unter

Removing Removing sticks stick ks

Placing Pl acing sticks stick ks

Stick ks Sticks

Counting direction Co unting d irection

Figure 3.5. Counting a large colony

After the count area has been well defined (use natural boundaries or place long sticks or poles, preferably with clearly visible markers on top, at regular intervals along the outer border of the colony), all the observers take position in a line perpendicular to the direction of movement. They all walk at similar speed in the same direction while distances between neighbouring observers are kept constant (preferably not more than 4 meters). Each observer counts all nests present in his four-meter-wide section, either at his right or left hand side. The counting ends when the observers have reached the other side of the colony. If the colony is counted only once during the breeding season, all nests should be counted, distinguishing between empty nests, nests with eggs and chicks. If counts are carried out on a monthly basis only nests with eggs should be included in the count.

MANUAL FOR MONITORING

PROCEDURE FOR COUNTING A LARGE GREY-HEADED GULL COLONY 1. Mark boundaries of the area to be counted 2. Place long sticks with clearly visible markers at regular intervals around colony edges to help observers to orient themselves especially in widespread colonies and to choose their transects 3. Take position in line, start walking and count your section (communicate with neighbouring observers about nests at borderline of sections). 4. Leave colony at other end and move away from area just counted. 5. Repeat counting in opposite direction next to the area just counted. 6. Make sure that the area bordering the transect just left is not counted twice. Therefore the person that counted the border of the transect should start on the same border while counting the next transect in opposite direction. 7. Discuss results and make notes about phase of breeding, presence of chicks, traces of predation, etc. Materials needed: 1. Binoculars 2. Sticks for marking the area 3. Notebooks and pen(cil)s 4. Tally counters

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

USING PARTIAL COUNTS FOR CALCULATING THE TOTAL NUMBER In case of colonies spread out over a large area it is also possible to count representative parts of the total area and then calculate the total number of nests present. First critically inspect the area. If there are a few colonies present surrounded by large areas without nests it might be better to count these colonies using the method described under â&#x20AC;&#x153;counting all nestsâ&#x20AC;? (see above). If this is not the case, you can do the following: The border of the total area is marked with 1.5m long sticks or poles and the total surface area (m2) is measured by GPS walking around the area from stick to stick. At least 10 sticks are placed at roughly similar distances from each other, but when the area is extremely large, more sticks should be used. Subsequently one clearly visible stick is placed in the centre of the area (use a GPS to mark it). Finally, starting at a stick placed at the border and walking in a straight line to the central stick, a 10 m wide band (further called transect) is counted by three persons. Two persons carry a 10 m long rope in between them. The middle of the rope is marked with a small flag or a simple knot. A third person walks in the middle making notes (figure 3.6). Each observer scans a c. 3.30 m wide area and the middle observer receives the information from the persons holding the rope and makes sure that no nests are counted twice. All nests are counted passing under the 10 m line. If there are no three persons available it is also possible that two persons do the job using a 5 m long rope. It is even possible that one person does the counting. He then needs a bamboo stick of 3 to 4 m length, which is held horizontally while walking. At both ends of the stick ropes are attached which touch the ground. All nests passing under the stick and between the ropes are counted (figure 3.6).

MANUAL FOR MONITORING

The number of transects should be adapted to the situation, with counting more bands when the area increases. In most situations the following number will be sufficient: - 10 transects of 10 meters wide, or - 15 transects of 5 meters wide, or - 20 transects of 3 meters wide. The surface area of all transects should preferably be close to 20% of the surface of the total area in order to have satisfactory results. The total number of nests in the area can be calculated as Ntotal = Na/Sa x (Sa + Sb), in which Na is the number of nests counted in the transects, Sa the surface of the transects and Sb the surface of the area not counted.

Figure 3.6. Calculation with ropes and transects

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

PROCEDURE FOR USING PARTIAL COUNTS TO CALCULATE TOTAL NUMBERS 1. Decide upon way of counting. 2. Mark boundaries of the area to be counted with sticks, place one stick in centre of the area. 3. Determine the total surface of area with a GPS. 4. Walk with a rope from a marker stick at border to the central stick and then back to another border marker etc. 5. Repeat counting transects at different locations 6. Measure the length of all transects (GPS). 7. Calculate the total number of nests (see formula). 8. Discuss the results and make notes about phase of breeding, presence of chicks, traces of predation, etc. Materials needed: 1. Binoculars. 2. Sticks for marking the area. 3. GPS. 4. Measuring rope or bamboo stick (see above). 5. Scientific pocket calculator. 6. Notebooks and pen(cil)s. 7. Tally counter(s).

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COUNTING ROYAL TERNS Counting all nests Royal Terns usually nest in very large and dense colonies (Figure 3.7). In such colonies it is impossible to make a nest count without dividing the area into clearly recognisable sections, which can be done by drawing lines in the sand using a stick. A relatively large number of observers should be involved in the counting action to minimise the time disturbing the birds. The following method has been successfully used for counting colonies of all sizes (figure 3.8). Persons participating in the count are divided into groups of two: "the marker" and "the counter". Starting at one edge of the colony, the marker of the first group draws a line in the sand, from one side of the colony to the other, thus creating a narrow strip (about 1,5 m wide) that can easily be counted by his/her group mate. The next group begins shortly after the first one has started, and after some time all groups work side by side. After the first group has completed counting the first section, it starts anew next to the last group. As a rule, the whole action is co-ordinated by one person who takes care that all sections are properly counted and keeps an eye on gulls taking eggs. Based on a number of such counts, it was found that a two-person group on average counts 80 nests per minute. Please notice that in older colonies there is a thick carpet of faeces covering almost the entire area between nests. This makes visible marking sometimes difficult without the risk that dried faeces are being pushed inside nest cups. Persons entering Royal Tern colonies should also pay utmost attention not to trample any eggs, as the distance between nests is very small.

Figure 3.7. Royal Tern colony

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

PROCEDURE FOR COUNTING ALL NESTS IN A ROYAL TERN COLONY 1. Watch the colony from a distance to get an impression of its size. 2. Decide how many persons need to be involved based on the count rate of 80 nests per minute per group. 3. Plan to be no longer than 20 minutes in the colony. 4. Discuss division of labour (form groups, appoint marker and counter, appoint co-ordinator). 5. Decide on where to start your count. 6. Carry out counting activities by using a tally counter. Check the number recorded by the counter after each pass in the colony and see if this appears to be correct. If the counter only gives 15 nests whereas you may have seen at least four times more, you know something is wrong and you should use another counter. Failures of tally counters occasionally occur. 7. Do not hesitate to stop counting, if there are many small chicks in the colony or if you witness many cases of egg predation by gulls. 8. Leave the colony area and come together to discuss results far enough away from the colony as to allow the birds to quickly resettle. 9. Write down the results in your notebook (make copy in camp). 10. Make notes on phase of breeding, % of nests with chicks, traces of predation, etc.

Materials needed: 1. Binoculars (do not carry them while working in the colony). 2. Stick for each group (1 m long, pointed). 3. Notebooks and pen(cil)s. 4. Field forms. 5. Tally counters.

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Figure 3.8. Counting Royal Tern colonies

MEASURING THE COLONY AREA USING A GPS In large Royal Tern colonies, the number of nests can be calculated by measuring the surface area of the colony (m2) and the nest density (nests/m2). This method, however, leads only to satisfactory results in case of large colonies (> 5.000 nests), which are more or less circular (i.e. not very elongated as is the case in many colonies which are parallel to the seashore). The surface area of the colony is measured while walking along the colony border holding a GPS as exactly as possible above the outer nests and with a clear visibility of the sky (i.e. not partially hidden by the person). Check that measuring conditions (which depend on satellite availability) are favourable, i.e. accuracy Âą3m. Place a stick at the starting point, so that you end where you started. Recent GPSâ&#x20AC;&#x2122;s calculate the surface of the area automatically, but it may be necessary to calculate the area yourself. In such cases you should take a waypoint every two

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

or three meters (or every second) while walking along the colony border and use the mode UTM instead of Lat/Long to have the coordinates in meters. The coordinates of the waypoints can then be plotted on graph paper and the surface area can be calculated (for details see annex 1 in Veen et al., 2004). Finally, the surface area (m2) should be multiplied by the mean nest density (nests/m2, see below).

PROCEDURE FOR MEASURING THE COLONY AREA 1. Watch colony to get information about its borders. 2. Check GPS (accuracy, right working mode?). 3. Quickly walk to the colony and place a stick at the starting point. 4. Walk at constant speed along the colony border holding your GPS above the nests at the border. 5. Proceed till you arrive at your starting point (stick). 6. Quickly walk away from the colony. 7. Calculate the surface area with the GPS and keep the data in the GPS memory to be downloaded and processed later. 8. Make notes on phase of breeding, chicks present (%), traces of predation, etc. 9. Use field forms not to forget any essential information. Materials needed: 1. Binoculars. 2. GPS + spare batteries. 3. Stick for marking starting point. 4. Notebooks and pencils.

MANUAL FOR MONITORING

MEASURING NEST DENSITY Nest density is measured by counting the number of occupied nests in 2x2 m squares at different places (at least four) within the colony (figure 3.9). Take representative samples. Squares are made by connecting four pegs with 2 meter long ropes (prepare this in camp). Inside each square, the number of occupied nests is counted. Count occupied nests (not number of eggs) and exclude empty nests and deserted eggs (there may be several) that usually lie between nests and are covered with faeces or partly buried in the sand. Should a nest be situated just under the rope, the position of the egg decides whether it is included (at least half of the egg should be inside the square). On having measured all squares, the average number of nests/m2 is determined by dividing the total number of nests by the number of m2 measured. The total number of nests present in the colony can be calculated by multiplying the colony area (m2) by the mean nest density (nests/m2). It is sometimes necessary to use this method, but it is essential to understand why this method is inferior to the total nest count method. There are two potential sources of bias. First of all the GPS does not accurately measure the surface areas as there is always some random variation in the coordinates given. The use of differential GPS (D-GPS) will resolve this problem but this involves substantial costs and therefore it is prohibitive. Secondly, the homogeneity of the colony determines the deviations from the mean nest density. Choosing representative squares is very difficult as one will usually choose squares which are not too far from the colony border to limit disturbance to a reasonable minimum. Border areas are usually occupied by less experienced birds and therefore may not have the same nest densities as the central parts of a colony. Also, colonies are sometimes established in areas where some Caspian Terns are already breeding, or where there are small sand dunes or other obstacles. These factors prevent the Royal Terns from making nests and therefore total nests calculated from densities in a few 4 m2 plots may (substantially) deviate from true mean density.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

PROCEDURE FOR MEASURING NEST DENSITY 1. Prepare tool for measuring nests in 2x2 m square (4 pegs connected by 2 m ropes) 2. Discuss way of working and divide tasks 3. Watch the colony and choose a representative plot 4. Put the pegs in the ground (make square with rectangular corners) 5. Count nests with eggs apparently incubated 6. Quickly leave the colony, discuss the results and make notes 7. Choose another part of the colony for the next measurement Materials needed: 1. Binoculars. 2. Tally counter. 3. Tool for making 2x2 square (pegs and rope). 4. Notebooks and pen(cil)s.

Only intact nests are counted. The example shows how to proceed: nest 3, 4, 5, 6 and 7 are counted, while nest 1 (empty), 2 and 9 (more than half of the egg outside square) and 8 (abandoned egg outside nest cup) are excluded.

Figure 3.9. Measuring density

MANUAL FOR MONITORING

COUNTING CASPIAN TERNS Caspian Terns breed in colonies varying in size from a dozen to several thousands of nests, with inter-nest distances usually between 1 and 5 meter. Small nest concentrations can be counted by one or two persons walking through the colony (see Slender-billed Gull). However, if a colony is large, counts should be made by several persons (preferably 4 or more), in order to minimise disturbance. The method is identical as described for the Grey-headed Gull: the observers take position in a line perpendicular to the direction of movement. They all walk at a similar speed in the same direction, while distances between neighbouring observers are kept constant (roughly 3 to 4 meter). Each observer counts all nests present at his/her right-hand side. If the colony is counted only once, all nests should be counted, distinguishing between empty nests, nests with eggs and chicks. If counts are carried out on a monthly basis only nests with eggs should be included.

Figure 3.10. Caspian Tern colony

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

MANUAL FOR MONITORING

MAKING MONTHLY COUNTS In most cases the monitoring of the colonies will be carried out at monthly intervals, choosing the same date each month. Because all breeding birds involved in the program have an incubation period of less than 30 days, nests with eggs counted in a particular month will have chicks during the count in the next month. So, when only nests with eggs are counted, it is possible to take the sum of all counts for calculating the total number of nests during a particular breeding season. For reasons of simplicity this number is regarded the total number of pairs breeding. However, there are a number of problems involved in using this method. Birds may loose their clutch and start re-laying. This may result in nests being missed or being counted twice. It may even happen that whole colonies are disturbed and deserted after which they settle on another island. Therefore, it is of great importance to keep an eye on such movements and to relate the sudden disappearance of nests in one place with the appearance of (a similar number of) nests in another place.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

4. MEASURING CLUTCH SIZE AND EGG SIZE INTRODUCTION There is great variation in the number of eggs that bird species lay. In general the number of eggs laid is adapted to the number of young that can be raised. As a consequence, clutch size may change with changes in food availability: when food is plentiful more eggs are laid as compared to situations in which food is scarce. It is also possible that the size of the eggs varies in relation to food availability. This is likely to occur in the Royal Tern, which lays only one egg. So, measuring clutch size and egg size may give information about food availability. There are a number of problems involved in measuring clutch size and egg size: (1) both tend to decrease in the course of the season, (2) clutches just started may be incomplete, (3) during hatching chicks may walk away from the nest leaving one (rotten) egg behind and (4) eggs may disappear because of predation (especially in small colonies and at colony borders). To minimize the effects of these problems, clutch size and egg size should be measured: • in the beginning or middle of the breeding season; • in colonies where breeding birds are about halfway done with incubation; • in relatively large and compact colonies, less sensitive to predation.

MANUAL FOR MONITORING

CLUTCH SIZE Clutch size is usually measured by two persons. One person mentions how many eggs are present in the nests (like 2, 2, 3, 3, 3, 1, etc.), whereas the other writes down the results. Empty nests are not counted. A representative sample is taken with respect to nests situated in the centre and at the edge of the colony. The sample size should be at least 100 nests. Mean clutch size is calculated by dividing total number of eggs observed by the number of nests included in the sample. It is worth considering the use of a camera to assess clutch sizes (keeping the camera well above oneâ&#x20AC;&#x2122;s head to improve the view and taking pictures under an angle). It has the advantage that one can work quickly and clutch size can be determined afterwards, limiting disturbance in a colony.

Figure 4.1. Measuring clutch size from photos taken in a colony

EGG SIZE Egg size is measured by two persons: one measures the eggs, the other is the administrator. In randomly chosen nests the length and width of each egg are measured with an accuracy of 0,1 mm using a pair of Vernier callipers (figure 4.2). Preferably 100 eggs per species should be measured. To minimise the time spent in the colony, you should have practised previously to use callipers. The administrator keeps an eye on possible errors being made by checking whether egg measurements are

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

within the normal range for the species (see Veen et al. 2003). The continuous checking for potential errors is an important task for administrators of all different activities when working in colonies. Reading errors can easily be made, but also easily be corrected. However, this needs an attentive administrator. Correcting errors after being back in the base camp is mostly impossible.

Figure 4.2. Measuring egg size

PROCEDURE FOR MEASURING EGG SIZE 1. Prepare the equipment. The person who will take measurements and the administrator practice before leaving. 2. Measure at least 100 eggs per species, taken from nests chosen at random. 3. The administrator writes down the measurements with a precision of 0.1 mm, taken by the other person. 4. The administrator verifies if the measurements fall within the known ranges for each species and if in doubt asks to repeat the measurement. Materials needed: 1. Vernier callipers 2. Data sheets 3. Notebooks and pen(cil)s

MANUAL FOR MONITORING

5. MEASURING CHICK CONDITION CONDITION INDEX AND CONDITION GRAPHS The growth of chicks is related to the amount of food they get from their parents. Consequently, the body condition of a chick can be used to obtain information about the feeding conditions for the parents at sea. The condition of a chick can best be measured as its body mass at a particular age. However, the age of chicks is often unknown. We therefore need a substitute for age, which is the length of head+bill. The length of head+bill appears to be nicely correlated with age. If the weight of a chick and the length of its head+bill are measured, they can be related to each other in a graph (figure 5.1). Two lines of reference are given in the figure: the line of maximum growth (upper line) and the line at which chicks die of starvation (lower line). Both lines are averages, so individual chicks may reach weights above and below both lines. Condition is now defined as:

Condition =

observed weight maximum weight at given length of head+bill

This condition index is independent of age and thus can be used for calculating the mean condition for groups of chicks of different age. Condition is given the value of 1.00, if chicks show maximum growth and 0.48 when it is equal to the starvation line. Mean condition of groups of chicks can thus be expected to vary between 1,00 and 0,48. High values show that chicks are well fed (black dots in figure), whereas low values indicate food shortage (open dots in figure).

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

Field observers will be curious to know whether the condition of the chicks they just measured is good or not. Therefore, forms were developed for different species in which the data can be plotted by hand (appendix 5). Visual inspection of the data will allow a general interpretation of the results in terms of good, medium or bad condition. They also allow for rapid inspection of outliers. Therefore it is recommended to use them in the field while measuring, as an extra check on the reliability of the data. Remember that back in the base camp little can be done to correct apparently erroneous entries.

Figure 5.1. Condition graph

MANUAL FOR MONITORING

CATCHING, MEASURING, AND WEIGHING CHICKS Small chicks can be measured and weighed in the nest. However, take care with small Royal Tern chicks (see chapter 2). Grey-headed Gull chicks of all ages can usually be found in the nesting territory, but their habitat usually contains relatively dense vegetation in which the chicks can hide. Medium to larger-sized chicks of Slender-billed Gulls, Royal Terns, and Caspian Terns usually react to human disturbance concentrating into groups and running away. The latter two species usually stay on the beach and great care should be taken to prevent them from entering the sea. Chicks in crĂ¨ches should never be chased over large distances and end up in a colony with Royal Terns still incubating their eggs. The best way to catch chicks is to surround them with a group of people, slowly chase them to an area with low vegetation and quickly catch as many as you can. But care should be applied when chicks are driven into vegetation. Even when this is done very carefully and slowly, the chicks may try to penetrate deeply into the vegetation. This may cause individuals being entangled and it will cost them a lot of energy to eventually get out again if they are not being retrieved, handled and released by the team. Do not include in your catch very small chicks that might accidentally be present at the place of catching. They might originate from a nearby nest and should stay where they are. Chicks caught are stored in well-ventilated boxes with a cover to protect them from the sun (figure 5.2). Chicks should be measured in a place where no other birds can be disturbed. Afterwards they should be guarded in empty boxes and brought back in groups to the place of catching and released together. When handling Slender-billed gull chicks, their condition should be continuously monitored as they regurgitate and defecate abundantly and they easily become wet. Therefore do not store too many birds in a single box and work quickly but accurately. Handling chicks is preferably done by three to four people dividing the tasks of ringing, measuring head+bill, taking the chicks' weight, and writing down the results on special data sheets. If there is enough assistance, one person can draw the condition graphs to check for outliers.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

Figure 5.2. Chicks in boxes

Figure 5.3. Measuring head and bill

Figure 5.4. Measuring head and bill with a special ruler

MANUAL FOR MONITORING

Head + bill are measured with a pair of Vernier callipers or a special ruler as depicted in figures 5.3 and 5.4. Weight is taken using hand-held Pesola spring scale (put chick first in a bag) or an electronic balance (put chick in open cup or PVC tube depending on its size). Subtract the weight of the bag, cup or tube from the reading or -better- tare the balance before weighing. Keep in mind that the weight of bags may change when they are contaminated with faeces or regurgitated food remains. Always write down the weight of the tube near the weight of the chicks. This makes it possible to correct your data afterwards, should you make a mistake. See also figure 5.5 and 5.6. Weighing, either with a balance or by using spring scales, is sensitive to wind. Therefore you should think beforehand on how to avoid wind effects, e.g. by putting a balance in a carton box or behind a wind screen.

Figure 5.5. Weighing with a Pesola spring balance

Figure 5.6. Weighing with a balance

PROCEDURE FOR CATCHING AND MEASURING CHICKS IN CRÈCHES 1. Prepare your equipment beforehand. 2. Check whether those involved in the work have experience with all techniques. 3. Find a group of chicks and watch them from a distance. 4. Discuss your plan and divide tasks (who carries boxes?). 5. Catch chicks as described. 6. Move away from the catching area and settle in a place not to cause disturbance. 7. Take measurements as described. 8. Put the chicks being handled in a special box. 9. Release the chicks in groups at the place of catching. 10. Once back in camp: complete data sheets, check and analyse data. (In case you have many data lying far above the line of maximum growth you may have included the tube in your weight measurements. However, when completing condition graphs in the field these risks have already been eliminated).

Materials needed: 1. Binoculars 2. Boxes with covers for storing chicks. 3. Bird rings with banding pliers and circlip pliers. 4. Vernier callipers or special ruler for measuring head+bill. 5. Pesola scales of 0-100, 0-300, 0-600 and 0-1000g. and bags. If possible use the smallest pesola's depending on the body mass of the bird in order to have maximum accuracy. A bird of 90g should be weighed with a Pesola of 0-100g, but a bird of 120 g with a Pesola of 0-300g. 6. Instead of Pesola’s: use an electronic balance 0-1000 g (±1g) in combination with cup and plastic/PVC tube. Use a small tube (length 18 cm, diameter 7-8 cm) for chicks of Grey-headed Gull, Slender-billed Gull and Royal Tern and a large one (length 25 cm, diameter 10 cm) for large chicks of Caspian Tern. Small chicks can be placed directly on the balance. 7. Notebooks and pen(cil)s. 8. Data sheets. 9. Graphs for different species.

MANUAL FOR MONITORING

6. MEASURING BREEDING SUCCESS MEASURE BREEDING SUCCESS Studying breeding success involves following (part of) the breeding population throughout the breeding process in order to determine the fate of the eggs and chicks. The ultimate goal is to get an insight in the number of chicks fledged per breeding pair. In addition, valuable information can be obtained with respect to environmental factors determining mortality of the brood, such as predation and food shortage. For instance, if many eggs disappear and we find eggshells near the nests, it is likely that predators are active. If chicks are in bad condition or dying, it is likely that there is food shortage. Information about egg-loss may also give an insight in the extent of re-laying. Breeding success data are usually split up as follows:

• Clutch size = mean number of eggs per pair (nest), • Hatching success = percentage of eggs hatched, • Fledging success = percentage of chicks fledging, • Breeding success = mean number of fledglings per pair.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

Peaceful situation without disturbance: chicks and parents spread out along the beach

Chicks soon after an intruder has left the area: they react to the disturbance by concentrating in crèches. Later on these crèches become progressively less dense and eventually dissolve.

Figure 6.1. How chicks that have left the colony react to disturbance

MANUAL FOR MONITORING

MEASURING HATCHING SUCCESS We can measure the hatching success by selecting a group of nests in a colony and marking each nest with a numbered small stick. Mark all nests in a small area; the sticks should not prevent birds from landing near the nest. Nests selected for this study should be a representative sample of the entire breeding population. So choose the nests located both in the center and at the edge of the colony. Try to mark nests when the birds start laying and quickly check then the contents of the nest every three days.

Figure 6.2. Nests marked with numbered sticks

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

PROCEDURE FOR MEASURING HATCHING SUCCESS 1. Determine how many nests should be followed for each species and choose study plots*. 2. Make uniquely numbered sticks for marking the nests. 3. Choose a part of the colony for marking nests. 4. Mark all nests present in a selected area on day 1; note nest contents; indicate study area with larger stick. 5. Check nests every 3 days; note nest contents and possible factors causing egg-loss; mark new nests; work with two persons (observer and administrator) and as quickly as possible to prevent predation. 6. Continue working in this way till the end of incubation. Materials needed: 1. Sticks for marking nests and one larger stick 2. Data sheets 3. Notebook and pen(cil)s

* At least 50 nests should be checked. How to choose these nests depends on the situation, especially the amount of disturbance caused during your presence in the colony. It may be useful to choose two or three different study plots. However, in each plot all nests to be checked should be close to each other to avoid that you have to search for nests. If you get the impression that your presence causes predation on eggs by gulls (which may greatly differ between sites) you give up measuring hatching success. In case of Slender-billed Gull and Royal Tern colonies taking photographs can speed up the checking of nests importantly. You then check the photos in your camp. However, numbers on sticks should be visible on the photos.

MANUAL FOR MONITORING

MEASURING FLEDGING SUCCESS The chicks of the Grey-headed Gull usually stay in the vicinity of the nest until about fledging. If they are ringed upon hatching they can be followed at 3-day intervals afterwards, although finding all chicks may need some intensive searching. The chicks of the Slender-billed Gull, Caspian Tern, and Royal Tern leave their nests long before the fledging age, which makes it impossible to follow them individually. A useful method is to build a chicken-wire wall, lined with mosquito screening, around part of the colony creating a socalled â&#x20AC;&#x153;enclosureâ&#x20AC;? (figure 6.2). The mosquito screening prevents the birds from damaging their bills. Chicks cannot escape from the enclosure. If they are (colour) ringed immediately after hatching they can be followed individually until fledging, both in the hand as well as by telescope from a hide. The enclosure should be checked every 3 days and chicks should be measured (head+bill) and weighed. A preliminary study with Caspian Terns showed that this method is applicable but that a small proportion of adults do not accept the chicks remaining in the enclosure. In such cases the chicks should be released outside the enclosure to prevent them from food and heat stress. Remember that our first objective is protecting the birds. Scientific research comes on the second place.

Figure 6.3. Enclosure

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

Preferably, hatching success and fledging success should be measured for the same nests. It is also possible to collect regurgitated pellets and faeces near these nests. You then collect data on breeding success and diet composition for one and the same groups of breeding birds.

PROCEDURE FOR CHECKING ENCLOSURES 1. Ring all chicks as soon as possible after hatching. Apart from steel numbered rings, use individually recognisable colour ring combinations. 2. Check the area (or enclosure) for chicks, every 3 days. 3. While searching, keep an eye on predation on eggs and small chicks. 4. Determine condition, make note of traces of predation and dead chicks. 5. Calculate/estimate fledging success based on the number of chicks having reached the (near-)fledging age. Materials needed: 1. Bird rings, pliers and other ringing materials. 2. Materials for measuring condition. 3. Data sheets. 4. Notebook and pen(cil)s.

MANUAL FOR MONITORING

Counting or estimating groups of chicks (nearly) fledged If we are dealing with a bird colony where eggs are laid synchronously and which is situated on a relatively small island, it may be possible to count or estimate the total number of chicks in the period they grow up. This involves determining the number of chicks on the island (usually in a crĂ¨che or spread along the waterline), shortly before the first birds actually leave the area. Preferably, several counts are made, once a week after which the highest number counted is chosen. Depending on the situation (rate of synchrony and possibilities for making an accurate count), this method can lead to rather good results.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

7. RINGING AND CATCHING CHICKS WHY RINGING BIRDS? Above all, it should be noted that only the skill and authorized personnel can perform ringing operations during which bird safety bonus above all other considerations Ringing involves catching a bird, placing a metal ring with a unique number and address engraved on it around one of the legs, and then releasing it. In this way a bird can be recognised as an individual. If a ringed bird is recaptured or found dead and the ring number reported to the address on the ring, one may obtain data on the movements and age of this bird. The major aims of bird ringing are: o o o o

to study migratory patterns; to identify important areas for a bird; to study causes of mortality (shot, found dead, caught, etc.); to determine the age of a bird.

In case you find a ringed bird, you should send a letter to the address engraved on the ring. In case the bird is alive, you should carefully note the inscription and the number on the metal ring. If there are colour rings added, you should also note the colours of these rings and its position on the legs. Also note the bird species and its condition. Does it look healthy, or weak, is it covered with oil, does it have a broken wing, etc. In case the bird is able to fly, do not remove the rings but let it fly away as you found it. In most cases a ringed bird will be found dead. Then you can remove the rings, but do not do so before you have written down all information about the position of the rings. You can flatten a metal ring and send it to the ringing station together with your letter in order to avoid mistakes. As a rule ringing stations always answer by giving you information on the place and date when the bird was ringed.

PROCEDURE FOR REPORTING A RINGED BIRD Mention the following information in a letter or e-mail to the address on the metal ring: - the number on the ring (and its colours in case colour rings have been used in addition to a metal one). - the position of the ring(s) on the leg, i.e. left or right and above or below tarsus joint. - the species of bird, its age, sex and plumage. - the date and the place where you found the bird (give coordinates if you have a GPS). - the possible cause of the bird's death. - your name and full address.

RINGING IN AFRICA In many countries, bird ringing is organised and co-ordinated by a national ringing centre. The ringing centre acts as the administrative unit for all ringing activities within the country and supplies rings to licensed ringers. To obtain the license, one should normally pass an examination. Not any national ringing centre is currently active in West African countries, the nearest is in South Africa. Therefore, ringing activities in these countries have been carried out only with rings from other countries. During the past decades, in Mauritania, Senegal, and The Gambia rings have been used from France, Belgium, The Netherlands, Germany, Great Britain, and South Africa. Between 1998 and 2003, ringing activities were carried out at the Langue de Barbarie and the Delta du Saloum in Senegal; in total, more than 10,000 chicks of the Grey-headed Gulls, Slender-billed Gulls, Royal Terns, and Caspian Terns were ringed. As a result many ringed birds are now present in these sites as adult breeding birds and can be individually recognized by using a spotting scope to read the ring number. In the framework of the seabird monitoring programme, chicks that are caught and handled (for instance, for the purpose of measuring their condition) will be ringed whenever possible. The most important techniques and tools used during catching and ringing will be briefly explained below.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

TYPES OF RINGS There are several different types of rings, which serve different purposes. The most commonly used rings are made of aluminium or stainless steel. They have a number and the address of the ringing centre engraved on the outside. For seabirds stainless steel rings are preferred, because they are resistant to salt water. In special projects coloured rings may be used, to enable identification of a bird from a distance using a telescope. The birds may be given a colour combination by using rings of different colours or colour rings with inscription (see figure 7.1 and 7.2).

Figure 7.1. Examples of metal and colour rings

Figure 7.2. Tern with colour rings

MANUAL FOR MONITORING

CATCHING BIRDS FOR RINGING A bird should be caught before it can be ringed. There are several methods to catch birds, varying from simple snares to wire-netting cages as large as a house. Here we will describe a few methods, which are commonly used in or near breeding colonies. Non-breeding birds Adult birds are often caught using so-called mist nets or Japanese nets. These nets are made of almost invisible thin black nylon netting and are placed vertically between poles on the ground. A net is divided in a number of â&#x20AC;&#x153;shelvesâ&#x20AC;? which act as pockets in which birds flying against the net are caught. (figure 7.3). Birds are caught because they do not see the nets. Therefore, catching usually takes place in twilight or at night. In most cases, the nets are placed in an area where the birds pass when flying between foraging areas and roost.

THE FOLLOWING RULES APPLY WHEN USING MISTNETS - Do not use the nets when there are strong winds. - Place the nets in a safe place (avoid that birds caught may end up in the water when the net is placed in a wet area). - Inspect your nets regularly (at least every hour). - Be prepared that you can catch an unexpected large number of birds. - Release the birds immediately (without ring) if you cannot properly handle them.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

Figure 7.3. Mist net and how it works

MANUAL FOR MONITORING

Breeding birds Birds sitting on a nest can be caught by using a small iron wire-netting cage. The cages are constructed in such a way that the breeding bird needs to pass through a door in order to reach the nest. Once the bird is sitting on its eggs, the door is closed by releasing the mechanism that keeps it in open position. This can be done by an observer sitting in a hide or by the bird itself. A simpler version of a wire-netting cage is the so-called fall-trap, which is shown in figure 7.4.

Figure 7.4 Fall trap for catching incubating birds

THE FOLLOWING RULES APPLY WHEN USING CAGES - Place the cage in such a way that the door faces the place from where the bird normally approaches its nest. - Take care that the bird cannot break its own eggs once it is caught (it may be useful to place dummy eggs in the nest). The firm attachment of cages for Caspian Terns need special attention as otherwise a bird may tumble it over while the researcher approaches. - Do not run to the bird once it is caught, but walk in a normal way. - Cover the eggs with grasses or other plant material after the bird has been released from the cage or replace the eggs by dummy eggs until the bird has resumed breeding. This is important, because the eggs can be taken by predators when the bird is away from the nest.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

Catching chicks Small chicks can be caught and ringed in the nest. However, in case of the Royal Tern one should take care that neighbouring chicks do not leave their nests ending up in parts of the colony from where they cannot return (see chapter 2). Grey-headed Gull chicks of all ages can usually be found in the nesting territory and ringed at the spot. Medium to larger-sized chicks of Slender-billed Gulls, Royal Terns, and Caspian Terns usually react to human disturbance by walking away concentrating into groups. How to catch such chicks by hand is described in Chapter 5.

Figure 7.5. Funnel with catching chamber

Chicks in crĂ¨ches can also be caught by chasing them into a funnel with catching chamber (figure 7.5). Large catches can be obtained in this way. However, this method should only be used by experienced ringers: If chicks concentrate in one corner of the catching chamber and pile up, some of them may suffocate. Besides, handling and ringing many chicks may take too much time, especially in hot climates. Surrounding the pen and keeping the chicks in the middle is a possibility, but the risks of suffocation and heat stress should not be underestimated.

MANUAL FOR MONITORING

THE FOLLOWING RULES APPLY WHEN CATCHING CHICKS - Avoid working at high temperatures, which is dangerous for small chicks. - Do not work in the late afternoon or evening. The chicks need time in daylight to return to their nest or parents. - Small chicks should always be returned to their nest and never be placed elsewhere. - Small Royal Tern chicks should not be ringed when neighbouring chicks walk away from their nest. - Larger chicks can be caught and ringed at some distance from the colony. However, they should be released where they have been caught.

HANDLING BIRD CORRECTLY Birds to be ringed should be handled correctly during catching, transportation and processing, to avoid stress and injury. This is important both from an ethical and a scientific point of view. With respect to the latter: injured birds may behave in an abnormal way, which may lead to abnormal recoveries and thus to wrong conclusions. It is important to hold the bird around the body and never by a wing, a leg or the head. Taking birds out of mist nets is something you should learn from an experienced ringer. First look from which side the bird entered the net; it should be taken out from the same side. Then try to release the legs first and hold these between your fingers. Usually, the whole body can then be lifted from the net and head and wings can be released (figure 7.6). Never pull hard or use any force! If you have problems releasing the bird ask an experienced colleague.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

Figure 7.6 Taking a bird out of a mist net

MANUAL FOR MONITORING

Figure 7.7 shows the correct way to hold a small bird or a chick: curve the four fingers of one hand over the birds back enclosing the birdsâ&#x20AC;&#x2122; shoulders and lower neck between the first and second finger. Avoid pressing the lower regions of the abdomen. A gentle but firm hold is all that is needed. With small chicks, the hold enables the rest of the hand to assist in supporting the leg to be ringed - between thumb and first finger. When transferring the bird from one person to another, turn the bird on its back, flatten the palm of the hand and transfer by holding the bird at the top of the thighs near the body whilst supporting with the other hand. For smaller chicks, hold a finger between the thighs. Large chicks may be transferred by substituting hands over the back in the holding position. When large birds are ringed, two persons should be involved in handling.

Figure 7.7. Holding a bird in the hand

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

Adult birds are usually kept in bags made of well ventilating cotton fabric. These bags should preferably be hanging and placed in a shady place (figure 7.8). Groups of chicks are stored in well-ventilated boxes with a cover to protect them from the sun (figure 5.2). Ensure that some space is left in the boxes. Keep the boxes horizontally and avoid that chicks are piled up in one corner. Boxes should be taken away from the colony area and chicks ringed in a place where no other birds can be disturbed. All chicks should be brought back to the place of catching and released together.

Figure 7.8. Bag for keeping adult birds

In many cases ringing is combined with taking measurements of the bird, such as weight and length of head+bill, and occasionally tarsus and wing. Taking the most appropriate measurements in the framework of a monitoring programme has been described in chapter 5.

MANUAL FOR MONITORING

THE ACTUAL RINGING Birds of different sizes need different-sized rings. Most ringing centres provide lists with ring sizes for bird species ringed by their co-workers. It is crucially important to follow the instructions of the ringing centres. Rings that are too large or too small may lead to a serious injury, including loss of leg or even death of the bird. If you do not have rings of the right size, simply do not ring your bird. Ring sizes advised by ringing centres should fit both chicks and adults. However, the legs of young chicks may be too small to hold the ring. Also in this case: do not ring. Table 7.1 gives the sizes of rings to be used for a number of colony breeding birds occurring along the West African coast. In all cases, some size variation is accepted, provided that you always check whether the ring properly fits your bird. Table 7.1. Ring sizes (mm) for West African colony breeding birds Species Grey-headed Gull Slender-billed Gull Royal Tern Caspian Tern

Ring sizes (mm) to be used 5,5 - 7,0 7,0 - 8,0 5,5 - 7,0 7,0 - 9,0

Rings are fitted on a birdâ&#x20AC;&#x2122;s leg, by using special ring pliers, which have holes for different ring sizes. As a rule there are pliers for small and large rings (figure 7.9).

Figure 7.9. Pliers with different holes

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

THE BASIC PROCEDURE FOR RINGING A BIRD IS AS FOLLOWS - Check both legs to make sure that the bird is not already ringed, either above or below the tarsus joint. - Select the correct ring size for the species. - Check that the ring number follows in the correct sequence on your data sheet. - Place the ring in the correct hole of the pliers. - Place the ring around the birdâ&#x20AC;&#x2122;s leg (figure7.10) in such a way that the ring number can be read when the bird is standing. This is important as rings can later be read by using a telescope. - Slowly, but firmly squeeze the pliers until the ring closes. Ensure that pliers are kept at 90 degrees to the bird's leg. - Examine the ring to ensure that it fits correctly, has closed properly (i.e. no gap or overlap) and that the inscription has not been damaged by scratches Adjust or replace the ring, if necessary. - Fill in the number on the condition data sheets, together with other information (when back in camp or office, the official data sheets of the Ringing Centre should be filled in as well. - Record all details of lost or broken rings on the data sheets too.

MANUAL FOR MONITORING

Figure 7.10. Fitting the ring around the leg

Note: Rings that do not fit well need to be removed. To do this carefully, place the two upward points of the ring remover on either side of the ring and gently squeeze as shown in figure 7.11. Rings that are damaged should not be used again.

Figure 7.11. How to remove a ring

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

RING ADMINISTRATION Proper administration is crucial for ringers. When ringing data are incorrect, it is impossible to draw conclusions from ring recoveries. This means, you should never include incorrect data in your administration. So, do not ring a bird if you are not sure about the species. If you have lost rings or some of your ringing data, mention this in your administration as “data lost” or “ring lost”. It is useful to have a standard list with you on which all necessary data can be filled in. Once back in the office, make copies of the list to be sure the data never get lost. You can make a copy by photographing it with a good quality digital camera with a rapid shutter speed (preferably <1/250 sec.). You need to check after having taken the image that all data are visible and that the image is in focus, i.e. not flue. On a standard list the following data should be filled in (see also Appendix 6): • ring number (metal ring) • colour rings (colours, location on leg) • bird species • age (chick or full grown) and sex (if known) • date of ringing • place of ringing (site and country) • coordinates of place of ringing

MANUAL FOR MONITORING

SUMMARY OF MATERIALS NEEDED FOR RINGING - Headlamp if you are mist netting - Materials for catching and keeping the chicks - Bird rings of appropriate sizes - Ringing pliers with different holes - Pliers for removing rings from leg - Materials to take morphometric measurements - Data sheets - Notebook and pen(cil)s - Bag for transporting and keeping ringing materials

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

8. COLLECTING PELLETS AND FAECES Information on the diet of colonial seabirds can be obtained by analysing regurgitated pellets and faeces for the occurrence of the so-called otoliths (from oto=ear and lithos=stone). Otoliths are the â&#x20AC;&#x153;hearing stonesâ&#x20AC;? of fish, which are located in the internal ear of teleost fishes (so not in rays and sharks). Since otoliths are species specific, they can be used to identify the species of fish eaten by the birds.

Figure 8.1. Breeding tern with pellet and faeces

Slender-billed Gulls, Royal Terns, and Caspian Terns all defecate around the nest and deposit regurgitated pellets near the nests as well (figure 8.2). In the course of the incubation period, pellets and faeces accumulate on the rim of the nest (Slender-billed Gull) or form a crust in the sand (Royal Tern and Caspian Tern) and can easily be collected. Royal Terns defecate around their nests, but Caspian Terns may use special latrines which therefore may contain faecal material from birds originating from different nests. It is assumed that faeces and pellets can give important information on the species composition of fish eaten by the birds during the incubation period. Apart from the mixture of pellets and faeces present near the nests, many fresh pellets of Royal and Caspian Terns can be found spread in the colonies. Such pellets provide additional information.

MANUAL FOR MONITORING

Figure 8.2. Otoliths of two different fish species

The analyses of pellets and faeces as well as the identification of otoliths should be done by specialists. However, the material to be analysed must be collected in the colonies. Special attention should be given to how the material is picked up from the nest or the ground. If the faeces are not properly collected, the samples may be contaminated with material from previous years. In case of the Slender-billed Gull: do not collect the entire nest, but collect the faeces from the nest rim. In case of the Royal Tern and the Caspian Tern: only collect the faeces which are on top of the soil. The number of pellets and the amount of faeces to be collected is given in table 8.1.

Table 8.1. Amount of pellets and faeces to be collected Species Slender-billed Gull Royal Tern Caspian Tern

Material to be collected Nb. of pellets Amount of faeces* 50-100 2 kg 100-200 5 kg 200 5 kg

* Avoid collecting a lot of sand or nest material!

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

PROCEDURE FOR THE COLLECTION OF PELLETS - Collect material in part of the colony where only one species is nesting (do not mix pellets of different species!). - Only fresh pellets (wet, not fallen apart) are taken. - Pellets are put together in a plastic bag. - Notes are made in duplicate: (1) with pencil on paper in plastic bag, (2) with water resistant marker on bag. - The following notes are made: date, place, species of bird, pellets, number of pellets, special information (collected inside or outside the nesting area, nests with eggs or chicks present, etc.). - Check your notes after the field trip.

PROCEDURE FOR THE COLLECTION OF FAECES - Collect material in single species colonies. - Collect material around nests with eggs shortly before hatching. - Do not collect complete nests (Slender-billed Gull) and avoid to collect a lot of sand.* - Notes are made: (1) with pencil on a piece of paper in plastic bag, (2) with water resistant marker on outside of plastic bag. - The following notes are made: date, place, species of bird, faeces, number of nests, special information (collected inside or outside nesting area, nests with eggs or chicks present, etc.). - Check your notes after the field trip.

MANUAL FOR MONITORING

9. PLANNING AND ADMINISTRATION THE PLANNING TABLE Monitoring activities should be planned each year, well in advance, taking into account materials to be used, human resources, and the budget needed. A planning table should be made. A time planning should be made in a way to minimise the disturbance. So, the planned activities should fit in with the birds' seasonal calendar and especially vulnerable species (e.g. the Royal Tern) should be the basis for choosing dates. For instance, in the Delta du Saloum most Royal Terns breed highly synchronized and the first chicks appear at about 6 May. Therefore, this species can best be counted in the first week of May to avoid disturbance of the small chicks. A month later, in the first week of June most chicks will have hatched and left the colony. Of course in this site all monthly counts should be undertaken on the same days each month. It should be noted that breeding periods may differ between sites and should therefore be adapted to the local situation. The planning table should include the various activities to be undertaken. What to choose depends on the nature of the site and the disturbance effects of certain activities. The first priority should be making a census of the number of breeding birds. Next comes measuring clutch size and egg size. Measuring chick condition and ringing chicks should only be undertaken when experienced field workers are available. Catching chicks may be especially dangerous on small islands surrounded by currents. You should always avoid that large groups of chicks enter the water in situations in which they are unable to return to the colony.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

A PLANNING TABLE SHOULD INCLUDE - Human resources, materials and financials needed. - A calendar with all activities indicated.

MANUAL FOR MONITORING

ADMINISTRATION It is of crucial importance to make notes when working in the field. If possible use data sheets in order to work quickly and to be complete. Also write down unexpected observations, such as traces of predation, high floods, human disturbance (fishermen, poachers, tourists...), dead chicks, etc. Such information might be important for the interpretation of the results. All information should be written in notebooks or on data sheets, checked afterwards and copied when back in the office, or photographed in the base camp. At the end of the breeding season a report should be written. Ask the help of an experienced colleague if you have problems doing so. Before circulating your final report, ask colleagues to read it. Maybe they have useful additions or comments. Before circulating your report check all numbers given twice, if possible by comparing with the original field forms. Your final report will be the only document, which will be circulated afterwards. Any errors will be copied over and over again and may never be corrected. Therefore it is your responsibility to provide a report without errors.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

FIELD NOTES SHOULD INCLUDE - Date, place, and species. - Name of site. - Names and addresses of observers. - All relevant data with respect to specific observations as described in this manual. - All other observations that may be important.

MANUAL FOR MONITORING

10. MAINTENANCE OF EQUIPMENT When working in the field, as well as in your camp or office, you will use equipment that needs maintenance. Many things are valuable and it will often be difficult or even impossible to buy new ones. So, equipment needs to be cared for.

ELECTRONIC EQUIPMENT Most electronic equipment is very sensitive to extreme heat, moisture, salt and dust. So, keep computers, cameras, calculators, electronic callipers, balances and other electronic equipment away from water and sand and do not expose them for prolonged periods to the sun. Especially salt water is able to ruin this type of equipment. When electronic equipment is not used, store it in a plastic bag in a dry and cool place. But never put your equipment in a plastic bag, when it is still wet: it will remain wet as long as it is in the bag. Take care with storing equipment in a small tent. In tropical environments small tents can become extremely hot inside. Check whether your GPS is waterproof or at least water resistant. If not, treat it as other electronic equipment. Most balances used for monitoring purposes are kitchen balances which are resistant to water. However, in certain types sand can come inside which may lead to malfunctioning. Therefore, balances should be cleaned now and then. Electronic calipers will be subject to corrosion as a result of the salt coastal environment, also when they are never directly in contact with salt water. When you have used your callipers in the field check whether they still move smoothly. Clean them if necessary. A general rule for cleaning delicate equipment which has been in contact with salt water or sand is as follows: sand should be removed by blowing and/or wiping with a soft brush, taking into account that the sand is removed from the equipment and not blown inside. The remains of salt water can be removed with a soft towel dipped in fresh water. But also in this case: take care that you do not worsen the situation by letting the fresh water enter the equipment.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

BINOCULARS AND TELESCOPES Like electronic equipment, binoculars and telescopes are also sensitive to sand, salt, water and high temperatures. However, there is a lot of variation in the quality of binoculars, which should be taken into account. Nowadays there are binoculars and telescopes available which are waterproof. If yours are not, keep them away from rain and salt spray when you are at sea. Sand is the greatest enemy of binoculars and telescopes as it may scratch the lenses. A general rule is, that you never clean dirty lenses with a towel: one particle of sand may cause a number of large scratches when rubbed against the surface of the lens. If you do this several times, your lenses will be damaged forever. When cleaning lenses you should always start with removing all sand particles. Hold your binocular or telescope upside down, so that the sand easily falls down. Then blow or gently brush, preferably using a special “blowerbrush”. Only when you are 100% sure that there is no sand left, you can wipe your lenses using a clean lens tissue in combination with special “lens cleaning fluid” or by “breathing” on the lens. When binoculars and telescopes have been in contact with salt water, they should be cleaned with a soft towel dipped in fresh water until all salt has been removed. Remember, that moving parts of binoculars are often made of aluminium, which may corrode under the influence of salt. This may lead to complete malfunctioning of the focusing system. All equipment used in the field should be inspected and cleaned before the field season starts as well as at the end of the season. At the end of the season bird bags and bird cases should be washed and cleaned, ringing pliers should be oiled and other equipment should be treated as mentioned above. Storing dirty equipment may be detrimental, as the infuence of salt continues during storage.

MANUAL FOR MONITORING

11. REFERENCES This manual is to a large extent an abridged version of: Jan Veen, Jacques Peeters and Wim C. Mullié (2004). Manual for monitoring seabird colonies in West Africa. Internal report, Wetlands International. More information about the monitoring of colonial seabirds in West Africa can be found in: Veen, J., J. Peeters, M.F. Leopold, C.J.G. van Damme & T. Veen 2003. Les oiseaux piscivores comme indicateurs de la qualité de l'environnement marin: suivi des effets de la pêche littorale en Afrique du Nord-Ouest. Alterra-report 666. Alterra, Wageningen, The Netherlands.

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

APPENDIX 1 CHECKLIST WITH MATERIALS FOR STANDARD MONITORING ACTIVITIES IN THE FIELD o Binoculars o Telescope o Camera o GPS o Batteries o Tally counters o Vernier calipers o Pesola balances o Electronic balance o Tube and cup (for weighing chicks) o Bird bags o Metal rings o Colour rings o Ringing plier o Plier for removing rings o Ruler (for measuring head+bill) o Ruler (for measuring wing length) o Clutch size forms o Egg size forms o Condition forms o Condition graphs (4 species) o Ringing forms o Small numbered sticks o Larger sticks o Notebooks o Pen(cils) o Graph paper o Plastic bags (20 x 3 ltr. bags)

MANUAL FOR MONITORING

APPENDIX 2 DATA SHEET FOR MEASURING CLUTCH SIZE

SHEET N° ... SPECIES: Slender-billed Gull

SITE: IaO

DATE: 1st May 2014

OBSERVER: .....

1 œuf ///// ///// ///// ///// /

Number of eggs in nest 2 eggs 3 eggs ///// ///// /////

///// ///// /////

///// ///

4 eggs ///// /////

///// ////

All nests

Total number of nests 21

114

x1 =

x2 =

x3 =

x4 =

Total number of eggs 21

228

294

243

All eggs 40

MEAN CLUTCH SIZE: All eggs / all nests = 583 / 243 = 2,40 eggs/nest

583

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

DATA SHEET FOR MEASURING CLUTCH SIZE

SHEET N° SPECIES:

SITE:

DATE:

OBSERVER:

1 œuf

Number of eggs in nest 2 eggs 3 eggs

4 eggs

All nests

Total number of nests x1 =

x2 =

x3 =

x4 =

Total number of eggs

MEAN CLUTCH SIZE: Total Général des oeufs / Total Général des nests = =

All eggs

MANUAL FOR MONITORING

APPENDIX 3 DATA SHEET FOR MEASURING EGGS

SHEET N째 RT/03/01 SPECIES: Sterne royale

SITE: Bijol Islands

DATE: 14 mai 2003

OBSERVER: Formation 2003

Nest n째 # eggs

length

width volume

58,00

40,60 39,70

57,70

41,20

62,69

42,49

61,98

42,61

57,93

39,88

61,00

41,75

57,10

41,70 40,90

69,30

61,80

41,70

60,40

41,50

62,10

41,20

59,47

40,13

59,50

42,00

58,20

42,00

62,30

41,56

31,20

40,22

61,18

41,04

57,40

41,70

59,20

39,50

Mean Standard Deviation

1,00

60,31

41,17

2,82

0,91

Nest n째 # eggs

Mean Standard Deviation

1,00

length

width volume

60,31

41,17

2,82

0,91

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

DATA SHEET FOR MEASURING EGGS

SHEET N째 SPECIES:

SITE:

DATE:

OBSERVER:

Nest n째 # eggs

Mean Standard Deviation

1,00

length

width volume

60,31

41,17

2,82

0,91

Nest n째 # eggs

Mean Standard Deviation

1,00

length

width volume

60,31

41,17

2,82

0,91

MANUAL FOR MONITORING

APPENDIX 5 DATA SHEET FOR MEASURING CHICKS

SHEET N° MtG/03/01 SPECIES: Mouette à tête grise

SITE: Bijol Islands

DATE: 14 mai 2003

OBSERVER: Formation 2003

Ring n°

Head+bill

Body mass

Ring n°

Head+bill

61,05

170

61,05

Body mass 170

66,69

202

66,69

202

70,14

218

70,14

218

69,53

229

69,53

229

67,46

225

67,46

225

58,91

62,94

171

62,94

171

58,03

142

58,03

142

67,80

181

67,80

181

70,30

229

70,30

229

67,20

225

67,20

225

64,90

210

64,90

210

68,30

231

68,30

231

65,20

206

65,20

206

72,50

257

72,50

257

66,29

215

66,29

215

64,00

206

64,00

206 179

73,00

179

73,00

58,30

151

58,30

151

65,75

241

65,75

241

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

DATA SHEET FOR MEASURING CHICKS

SHEET N째 SPECIES:

SITE:

DATE:

OBSERVER:

Ring n째

Head+bill

Body mass

Ring n째

Head+bill

Body mass

MANUAL FOR MONITORING

APPENDIX 5 CONTINUATION GRAPHS FOR PLOTTING DATA ON CHICK CONDITION

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

MANUAL FOR MONITORING

APPENDIX 6 RINGING FORM Ringing form to be used in the field only (make copies). Afterwards the data need to be transferred to the relevant foreign Ringing Centre in electronic format, which differs per Ringing Centre.

RINGING LIST Ringed by: ...................................... ...................................... ......................................

Ring size ............. mm

Use only one ring size on each form. Note rings in an orderly way, i.e. .....01, .....02, ....03, etc. Indicate the date as follows: DD-MM-YY. Immediately make copies of each list and keep in a safe place. Age: P = chick; FL = fledgling (chick able to fly); FG = full-grown; 1CY = first calendar year, 2CY = second calendar year, etc.; ? = age unknown. For further details see back of form.

Ring n째

Species

M/F

Age

Locality Date (Village/province)

Details

BREEDING COLONIES OF TERNS AND GULLS ALONG THE WEST AFRICAN COAST

Ring n째

Species

M/F

Age

Locality Date (Village/province)

Details - only use the following codes: JU - juvenile plumage EC - eclipse plumage (ducks) MN - notes of moult taken OA - Escaped from captivity

OM - bird sick or injured BC - put on colour rings DE - displaced (give details)

Details

The Atlantic Ocean bordering West Africa is very rich in fish. As a consequence the area is also very rich in fish-eating birds, which breed in huge numbers in colonies in protected areas, such as the Parc National du Banc d’Arguin (Mauritania), the Parc National du Delta du Saloum (Senegal) and the Bijagós Archipélago (Guinea Bissau) and a few other sites. Seabirds are increasingly threatened by fishing activities, pollution, predation, disturbance and egg-poaching by humans... Breeding sites are especially vulnerable and urgently need protection. In order to better protect West African seabirds, FIBA has taken the initiative to develop the ALCYON project, which is funded by the MAVA Foundation. In the framework of this project, breeding colonies of terns and gulls are studied and park staff is trained in monitoring techniques, which are described and explained in this manual. The data collected are used by BirdLife International to identify the marine Important Birds and Biodiversity Areas (IBAs), implement appropriate measures and achieve effective protection for the most important seabird areas.