How to build animal houses and more
The ecological impact of animal nests and burrows
Nest building and burrow construction have costs. These costs are not well known but some attempts have been made to measure them either directly as energy and time consumed, or inderectly as fitness changes. Calculation of the energetic cost of web construction in the spider Araneus diadematus is an example of the former approach, and the cost of nest construction in the Eastern Phoebe measured as clutch reduction compared with nest reuse, is an example of the latter. In some instances at least it can be seen that the result of these buildings efforts is a direct transfer of function from some other system to the artefact through evolution; for example, McNab showed that naked molerats which live permanently in the stable temperature of their burrow system had almost completely lost their power of physiological thermoregulation. 3
Nests and burrows can also reduce the biological hazards of the external environment; for example, the paper carton nest of the tropical polistine wasp Nectarinella Championi is surrounded by a field of hairs capped with sticky droplets apperently to repel ants. The purpose of this paper is to present the argument that by their nature nests and burrows can come to exert important influences upon certain habitats and a number of different ways in which they do this can be identified. These have implications for the understanding of social evolution, species diversity and habitat stability which deserve greater attention. The reinforcement of social life There is evidence that building and burrowing behaviour themselves may be factors promoting social life. The evolution of social life in the Hymenoptera was preceded by a series of changes in the order and nature of nest construction and provisioning behaviour. One of these was from mass to progressive provisioning, a necessary prerequisite for the evolution of cooperative brood care. However, progressive provisioning was accompanied by a slower rate of egg production and longer adult life. Long life and low fecundity are features of a K-selected biology and Hansell, using a model modified from Horn, argued that nest building, by creating a more constant environment, generates a population more frequently near to the carrying capacity of the environment. This makes the foundation of a new colony more difficult How to build animal houses and more
and inhibits leaving of the home nest, leading to more complex colony life and further elaboration of the nest. This association between nest preparation and features of a K-selected biology has been noted by other authors. Halffter and Edmonds describe a negative correlation in dung beetles between nest burrow complexity and fecundity. Kent and Simpson have made the excitng discovery that in the ambrosia beetle, Australoplatypus incompertus, a foundress female of low fecundity is later supported by a small retinue of workers living in galleries, exavated deep in heartwood of living trees, which may remain active for more than 35 years. Nevo lists K-selected biology as one of the results of competition in populations of subterranean mammals. The most extreme evidence of this is shown in by the naked molerat. The possible importance of nest building or burrowing in promoting social evolution has been formulated in an alternative but not mutually exclusive hypothetsis. West Eberhard suggests that the reluctance of individuals to leave the nest results from the high cost of nest foundation. A similar hypothesis stresses the possible prize of inheritance resulting from staying compared to the risks of emigration and energetic costs of construction. It is a prediction of all of these hypotheses that colony sizes may become larger, residence long term and environmental modification progressive and potentially great.
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The alteration of habitats There is evidence that some locations or even major habitat types have been gradually altered and ultimately even dominated by a population of burrowers or nesters that has been resident over what in zoological terms are long periods of time. The nest mounds of a number of species of megapodes are added to year after year. Frith records a mound 3m high and 18m long. There are sites in Northern Australia where several hundred mounds may occur together, some over 10m high with a basal area of 2000m2. These have led to a heated debate concerning wheter they are mdidens created by Aborigines or nest mounds of the scrub fowl, Megapodius reinwardt. In New Caledonia mounds of 50m diameter and 4-5m high have been interpreted as either archaeological sites of former nest mounds of the extinct Sylviornis neocaledoniae. In Cape Province, South Africa, the landscape is covered over large areas with more or less circular mounds about 30m across and 2m high. These are apparently the consequence of the combined burrowing activities of termites. Microhodotermes Viator and molerats. A similar landscape ‘Mima Prairie’ is found in the USA, which is due to the burrowing activity of pocket gophers and in Argentina due to species of Ctenomys. Schroder and Geluso found that the distributeion of occupied and abandoned Dipodomys spectabilis mounds considered together was uniform, suggesting both that interactions between neighbours caused spacing out and that mounds abandoned during population How to build animal houses and more
decline were later reoccupied; effectively, therefore, a situation of long-term gradual habitat modification to a consistent pattern. Termite activity alone may be responsible for even greater landscape alterations. In South Africa the termite Odontotermes is thought to be responsible for a regular corrugation of the land surface into parallel gullies about 50m apart seperated by ridges of about 2m height which may be 1km in length. In the Loita plains, Kenya, termite activity produces circular features about 7m across at a density of 650km2 with an arc of tall grass growth on the up-gradient side. Vegetation arcs which may be several hundres metres across stretch in regular wave-like patterns for many kilometres across otherwise bare semi-arid regions of Somalia. Macfadyen suggests that these are similar to the mima-like landscapes of southern Africa. These arcshaped features are also recorded from other semi-arid subtropical regions, e.g. the Sudan and Australia. I suggest that such major alterations to the topography are the result of consistent, possibly continuous, activities over long periods of time, possibly hundreds even thousands of years. An occupied mound of Macrotermes goliath in Africa was found to contain iron age burials of about 700 years old. Neal suggests that badger setts in Britain of several hundred years old are not rare. Certainly they can attain remarkable complexity; a partially excavated sett was estimated by Roper et al. to have 879m of burrow, contain 50 chambers and have 178 entrances.
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The concentration of resources The extension of a nest or burrow over time represents an accumulation of building effort and material; food storage within it also represents the concentration of the habitats’ resources. This altered and patchy redistribution of valuable resources in the habitat has important consequences. Nest material In honeybees a considerable proportion of a growing colony’s energy input is needed for the synthesis of wax comb. In mature colonies, however, this cost can be largely ignored, since the wax is then recycled. Comb wax has altered mechanical properties compared with freshly secreted scale wax resultin from mandibulation and addition of salivary secretion. Recycled wax therefore saves on behavioural and psychological costs of comb manufacture using fresh wax scales. Recycled wax may also contain fragments of larval cocoon silk adding to the comb’s strength and stiffness. Comb recycling is also shown by stingless bees, e.g. Trigona terminata. Recycling of nest material is widespread in the manufacture of paper nests by social wasps; for example, in the stenogastrinae and vespinae. All Vespa species also reinforce comb pillars by adding pieces of recycled cocoon silk. In the ponerine ant Prionopelta amabilis, fragments of former silk cocoons are used to line pupal nest chambers apparently to control humidity. How to build animal houses and more
Food Larders and granaries are especially likely to evolve in habitats where food supply has periods of surplus and scarcity and where it is amenable to long-term storage. This is best illustrated by storage of honey, hay and seeds. The honey of the honeybee Apis melifera and of stingles bees such as Melipona and Trigona is essentially nectar made resistant to fermentation. In honeypot ants, such as Myrmecocystus and other genera it is again mainly sugars which are stored using the greatly swollen crops of the largest workers as the storage containers. The storage of hay and seeds is characteristic of specialists among widely different animals. Magnetic termites, Amitermess meridionalis and Amitermes Luarensis gather and store large quantities of plant fragments in their 2-3m high mounds, as do members of certain other termite genera, notably Nasuitermes, repanotermes and Trinervitermes. Among mammals, hay storage is shown by pikas in the meadows of their mountain habitat. The largest hay piles can be 6000g, enough to last a pika an estimated 6months. Seed-storing ant specialists are found chiefly among the subamily Myrmicinae. Typical of these are species of Monomorium, Pheidole and Messor. Colonies of the desert ant Messor pergandei have been reported to use seed stores to survive 12 years of severe drought.
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Building animal houses
On the next pages you’ll see some building plans to make your own animal houses. There won’t be perfect descriptions how to make it, only the requirements and sizes of certain planks and other material will be given. Animals do not have instructions either, they have to build their nests and burrows with things they have found in nature. Keep in mind that animals need a lot of space. Would you like to be locked up all day? Don’t think so. Use your brain and creativity to make the perfect house for your animals.
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e c
1.1
a
b b
a
b
b
d
d 2
a
3
b
a
2
e d
b b
c 1.2
2x
b
4 a
e d
a
5 e
How to build animal houses and more
Birdhouse
Requirements: 10 mm wooden planks hammer nails wood glue Sizes: a: 290 cm b: 300 cm c: 110 cm s: 70 cm
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b
b g
2x
i
g
e
h
2x
b
2x
e
4x
b
b f
f
b
b
c
a
a d
2x
e
How to build animal houses and more
Rabbit house
Requirements: even wooden planks nettings hammer nails stapler Sizes: a: 110 cm b: 41 cm c: 35 cm d: 75 cm e: 85 cm f: 12 cm g: 8 cm h: 50 cm i: 20 cm
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c
a
4x
a
a
2x
a
d
b
3x
e
26x a 15x a
How to build animal houses and more
Insect hotel
Requirements: even wooden planks hammer nails wood glue bamboo twigs
Sizes: a: 40 cm b: 60 cm c: 20 cm d: 10 cm e: 85 cm
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a b
2x
c b
4x
b
How to build animal houses and more
Burrow
Requirements: garden or open space in nature plastic pipelines shovel some muscles sizes: a: 300 cm b: 20 cm c: 150 cm
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a
b
2x
c
2x
b
a
How to build animal houses and more
Ant house
Requirements: glass 10 mm wooden planks sand sizes: a: 100 cm b: 40 cm c: 10 cm
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COLOFON
Title: How to build animal houses and more Lay-out: Silke Vandekerckhove
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Index 1. The ecological impact of animal nests and 3 burrows 2. Building animal houses Birdhouse Rabbit house Insecthotel Burrow Ant house
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3. Colofon
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How to build animal houses and more