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Suffolk Natural History, Vol. 37 THE ROLE OF REINTRODUCTIONS IN CONSERVING BRITISH BIRDS IAN CARTER
Bird reintroductions and introductions are undertaken for various reasons. Gamebirds and wildfowl are often valued as quarry species and species such as Pheasant, Red-legged Partridge and Greylag Goose are now widespread as a result of introductions for shooting. Following extinction, the Capercaillie was reintroduced to Scotland in the 1830s for the same reason and, despite declining numbers, is still present today. In some cases, birds were introduced for aesthetic reasons, simply because individuals wished to see the species established in their local countryside. The Little Owl was released by several individuals in the second half of the 1800s for this reason and is now relatively common and widespread in England and Wales. This talk will concentrate on reintroductions that are carried out purely for conservation reasons. The term reintroduction will be used in its wider sense to cover not only projects involving species that have been lost from most or all of the country, such as the Red Kite, but also species like the Barn Owl which is still widespread but now has a rather patchy distribution. There has been a rapid increase in bird reintroductions for conservation reasons over the last few decades in Europe and North America, many involving birds of prey. This group of birds is often involved in reintroductions because they are highly sensitive to pesticides (such as organochlorines) and human persecution, and many species have low rates of breeding productivity and poor powers of natural recolonisation. They can therefore be lost from large parts of their range and may find it difficult to spread back naturally. In Europe there have been recent projects involving Eagle Owl, Osprey, Red Kite, Lesser Kestrel, Peregrine, and Black, Griffon and Bearded Vulture. IUCN reintroduction guidelines and legal considerations The following is a summary of the main points contained in detailed guidelines produced by the Species Survival Commission of the IUCN in 1995. English Nature would not support a bird reintroduction project unless it was shown to meet these guidelines in full. • Reintroductions are concerned with the re-establishment of a species or sub-species that formerly occurred in an area.
• The reasons for the loss of the species should be well-understood and should no longer pose a significant threat in the release area. • There should be a sound understanding of the natural history of the species and the release area should provide suitable habitat, despite changes that may have occurred since the species was last present. • Releases should be as close as possibly genetically to the original native population.
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• Collection of individuals for release projects should not adversely affect the donor population. • Local people in the release area should be consulted and be generally supportive of the project. • There should be a well designed programme of monitoring so that the success of the project can be assessed and any problems identified at an early stage. A point not covered by the guidelines, probably because it is simply common sense, is the likelihood of natural recolonisation. There is almost universal agreement that the natural recolonisation of a species is preferable to a time consuming and costly reintroduction. English Nature would not support the reintroduction of a species unless natural recolonisation was unlikely within a reasonable period of time. The IUCN guidelines are not enshrined in British law and there are currently no legal restrictions on the release of most naturally occurring British birds. An individual with legally acquired stock (through captive breeding for example) requires only the permission of the landowner to proceed with a release project. A few species, where specific problems have been identified, have been listed on schedule 9 of the Wildlife and Countryside Act (1981) and now require a licence from government before they may be released legally. These include Barn Owl and White-tailed Eagle in addition to many nonnative species that have become established in the wild. Bird reintroductions in Britain Very few British birds are suitable candidates for reintroduction, meeting all of the guidelines summarised above. This is for two main reasons: 1. Most species that have been lost from parts of their range in Britain have done so as a result of factors that are still operating and so reintroduction is clearly inappropriate. The main factors include loss of semi-natural habitats, intensification of agriculture and, for a small number of species, climate change. 2. Birds are generally very mobile and most species have good powers of natural recolonisation. If the reasons for loss or decline are redressed then most species will spread back naturally within a reasonable period of time. The Sparrowhawk and Peregrine provide two good examples of how quickly natural recolonisation can take place. Both were wiped out from most of their British range as a result of the use of organochlorine pesticides, which accumulated in species at the top of the food chain. These chemicals were restricted in use or banned completely in the 1960s and, within about 25 years, both species had made an almost complete recovery in numbers and range. There was clearly no need for reintroduction projects for either of these species. The table below includes bird species where, for reasons of nature conservation, reintroduction projects have either been carried out, are in
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progress, or, have been proposed for the future. This currently involves only ten species in Britain and Ireland, a very small proportion of the 250 or so regularly occurring species. They fall into two main categories: 1. Raptors that have been lost from all or parts of their range as a result of human persecution, but where the landscape remains suitable. 2. Species lost from all, or parts, of their range as a result of the loss or inappropriate management of their habitat but where the reinstatement of appropriate management may now provide suitable conditions. Bird Reintroductions for conservation reasons in Britain and Ireland Projects carried out Projects in progress Project proposed Barn Owl1 Osprey Chough Goshawk Red Kite Cirl Bunting White-tailed Eagle Corncrake Golden Eagle (Ireland) Great Bustard 1
Projects ongoing in some areas
Objections to reintroduction projects Although there is no doubt that the Red Kite is a suitable candidate for reintroduction, meeting all the IUCN guidelines, and the project enjoys overwhelming support in the release areas, there are some people that believe this, and other similar projects, should not be carried out. The main objection has come to be symbolised by the plastic, coloured wing-tags that are fitted to Red Kites before they are released as part of the necessary monitoring procedures (see Plate 8). On several occasions I have met birdwatchers who have been watching a Red Kite in the wild but found that the experience was not an enjoyable one because the bird had clearly visible wing-tags. For these people, there is no pleasure in seeing such a bird because the wing-tags show that it has been handled by man, possibly in captivity, and is therefore not considered truly wild. I sympathise with this viewpoint and I can remember having similar feelings when a Black Vulture I was watching in the northern hills of Mallorca came close enough for its wing-tags to become apparent. Suddenly, what had been a hugely impressive symbol of these rugged, wild mountains came to represent the degree to which man’s activities had adversely affected the area’s wildlife, necessitating hands on conservation action. Despite this sort of, perfectly understandable, reaction, it is vital to try and take a long-term view. The wing-tags are a necessary part of a project of this nature in the first few years but, if all goes well, and Red Kites continue to increase and spread, then, in a few years time, they can simply be left to themselves with no further need for human interference. Not too many birdwatchers think twice about the history of the species when watching a Little Owl or Capercaillie, because these birds have been established in the wild for a long time and man’s involvement has been all but forgotten. Human
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interference has long been an accepted part of the management of semi-natural habitats and, in the few cases when it becomes necessary, it is perfectly acceptable to give individual species a helping hand. The benefits of reintroduction projects Reintroductions are not only of direct benefit to the individual species involved but also confer wider conservation benefits that generally fall into one of three categories. (i) Encouraging a wider interest in nature conservation though work with high profile species. The Red Kite project has been an excellent example of using work on a high profile ‘flagship’ species to generate interest in bird conservation. The release of the young birds from their aviary attracts considerable media interest each year, leading to widespread coverage in both local and national newspapers, radio and television. The birds themselves are very obvious in the release areas, as they spend much time drifting slowly, low over fields and villages, and even people with only a vague interest in wildlife are often keen to find out more about ‘their’ local Red Kites. Talks given in villages within the reintroduction areas can attract up to 200 local people, showing just how high the interest levels are. All this positive publicity has been valuable at a time when raptors generally have been getting something of a bad press in sections of the media. The Red Kite project has only been possible as a result of cooperation with farmers, gamekeepers and landowners, and is a useful example of what can be achieved when conservationists and landowners work together. (ii) Promoting improved management of important wildlife habitats and in the wider countryside. There is currently a proposal to reintroduce the Chough to Cornwall, although, as yet, it is not clear whether there is a sufficiently large area of suitably managed coastal grassland to support a self-sustaining population. The reintroduction proposal may encourage interested landowners and conservation organisations to try to increase the area of grassland under appropriate management in order to improve the chance of the project being given the go ahead. This will clearly be of direct benefit to the Chough but will also help a range of other species that are dependant on well-grazed coastal grasslands. Work carried out to help Cirl Buntings in south Devon has already resulted in changes to arable stewardship prescriptions and an increase in uptake rates among local farmers. The Cirl Bunting population is currently restricted to a relatively small area, surrounded by intensively managed farmland that is not suitable for the species. It is therefore highly unlikely that the population will be able to expand its range naturally and spread to other suitable landscapes in southern England. One idea currently being discussed is to reintroduce the species to an, as yet unknown, area in south-east England where agrienvironment measures such as arable stewardship could be used in the same way as in south Devon to improve the landscape for Cirl Buntings.
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Encouraging farmers to retain weed-rich stubbles over the winter is just one of the measures that would benefit Cirl Buntings as well as other priority farmland species such as Linnet, Corn Bunting and Tree Sparrow. (iii) Publicising and helping to tackle conservation problems. The Red Kite is highly vulnerable to the use of illegal poison baits in the open countryside. Intensive monitoring carried out as part of the reintroduction programme, including radio-tracking, has helped to highlight this problem. Pictures of birds that have been poisoned are very effective in raising the profile of this issue and can provoke strong reactions from people concerned about this type of activity taking place on their doorstep. As it is very difficult to gather enough evidence to prosecute someone for using illegal poison bait, the influence of local people on individuals within their community is one of the most effective means of changing long-established practices. Red Kites are also vulnerable to accidental secondary poisoning through scavenging on rats poisoned with highly toxic anticoagulant rodenticides. Once again, the Red Kite has been used to draw attention to this issue and as a ‘flagship’ to encourage people to use the less toxic products such as warfarin and to follow guidelines on the safe use of rodenticides. If further monitoring of Red Kites shows that secondary poisoning is preventing populations from increasing and recolonising new areas then it may be necessary to press for legal restrictions in the way that the more toxic rodenticides can be used. Any action taken to reduce the threat from illegal poisoning and secondary poisoning will benefit a range of other species that are also affected by the same problems. Buzzards and Ravens may be able to increase the rate at which they are currently spreading from west to east, following past persecution, if illegal baits become less frequent. Barn Owls, Polecats, Weasels and Kestrels may all benefit from the safer use of rodenticides as all are known to feed on poisoned rodents. Inappropriate reintroductions Despite the undoubted conservation benefits of carrying out well-planned reintroductions there are some very real dangers from carrying out projects that are inappropriate and, for this reason, it is vital that the IUCN guidelines are always followed carefully. Examples of some of the most obvious potential problems are dealt with under the headings below: (i) The potential for direct adverse impacts on wildlife. Before the release of Barn Owls was restricted by the inclusion of the species on schedule 9 of the Wildlife and Countryside Act it was thought that as many birds were released each year as were already present in the wild. In some cases the captive-bred birds were poorly adapted for life in the wild and, although they stood little chance of surviving in the long-term, in the shortterm they competed for resources such as nest sites with wild birds. There were also examples of birds of non-native races being released, and the risk that diseases picked up in captivity could be spread to birds in the wild.
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(ii) Attracting attention away from the main factors adversely affecting a species. If reintroductions are carried out inappropriately, either because the habitat is unsuitable, or natural recolonisation is likely within a short time, there is a risk that the real reasons why a species is doing badly will be forgotten. Farmers may not worry too much about the way that they manage their land if simply releasing more birds is seen as an effective conservation strategy for species that are lost. English Nature sometimes receives proposals for reintroductions involving species that are still widespread in Britain such as Tree Sparrow, Skylark or even Song Thrush. These species, along with other farmland seedeating birds, have declined because of the increasingly intensive way in which our farmed landscape has been managed. Where the habitat remains suitable they are still common and, if conditions are improved in an area from which they have been lost, they are able to recolonise naturally. (iii) Animal welfare issues If birds are released in circumstances where they have little chance of survival this is likely to be in contravention of legislation under the Abandonment of Animals Act (1960). This might apply if birds are released into an area of unsuitable habitat without an adequate food supply, or if projects involve captive-reared birds that have learnt to associate food with humans and are poorly adapted for life in the wild. Conclusions The title of this conference is ‘Playing God or Gardening’. Unfortunately, we have been playing God in Britain for a very long time and, as a result, a small number of bird species that were formerly widespread have had their ranges drastically reduced or have been lost completely. Carefully planned reintroduction projects are now being used, with just a handful of species, to put this right and restore what is a more natural situation. These projects are also being used as an opportunity to help generate a wider interest in bird conservation, encourage improved management of wildlife habitats and tackle some of the problems that are affecting a range of our native wildlife. Despite the obvious benefits of species reintroductions this type of project should remain as a relatively small part of bird conservation in Britain. The loss or neglect of semi-natural habitats and the intensive management of much of the wider countryside are by far the most important threats to the majority of declining species, and inappropriate and unnecessary reintroductions should not be allowed to distract attention away from these, and other, problems. Ian Carter English Nature Northminster House Peterborough PE1 1UA
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I. Carter Plate 8: The main objection to the release of captive-bred Red Kites has come to be symbolised by the plastic, coloured wing-tags that are fitted to the birds before they are released. For some people, there is no pleasure in seeing such a bird because the tags show that it has been handled by man, possibly in captivity, and is therefore not considered truly wild (p. 10).