The first British bird to be reintroduced for conservation reasons was the White-tailed Eagle Haliaeetus albicilla, starting in 1975 (after two earlier failed attempts). Since then, the approach has been adopted with increasing regularity. The first Red Kites Milvus milvus were released in 1989, followed by the Osprey Pandion haliaetus project at Rutland Water in 1996. As we entered the new century, the pace picked up, with projects for a suite of species either extinct in Britain or lost from large parts of their former range, including the Great Bustard Otis tarda, Corn Crake Crex crex, Common Crane Grus grus, White Stork Ciconia ciconia and Cirl Bunting Emberiza cirlus. Proposals have recently been put forward for reintroducing the Hen Harrier Circus cyaneus to southern England and the Golden Eagle Aquila chrysaetos in Wales. Success has varied between species with some already well on the way to becoming re-established, while progress for others has been slow and the outcome is, as yet, uncertain.
Reintroductions have always been contentious. They are expensive and resource intensive, and involve a level of direct human interference with wildlife that not everyone is comfortable with. My involvement with the Red Kite reintroduction in England left me in no doubt as to the dissenting views of some birdwatchers (Carter 2019). For many years, the surviving Welsh birds were seen as genuinely wild and worthy of appreciation while the released birds were deemed ‘artificial’ and less widely valued.
Today, I think that a majority of birders accept that reintroductions are justified when they provide hope for birds lost as a direct result of human activities. White-tailed Eagles, Red Kites and Ospreys were wiped out (or almost so) by persecution; Great Bustards, Corn Crakes and Cirl Buntings were adversely affected by a decline in habitat quality. There may have been debate about whether reintroduction was the right approach but few questioned the legitimacy of trying to restore native birds lost, or greatly reduced, in less enlightened times. A little short-term meddling (and perceived loss of ‘wildness’) is a small price to pay for the return of native birds to our landscapes in the longer term.
Early successes and the development of ever more effective captive-rearing techniques has led to a surge of interest in release projects in recent years, particularly for high-profile species that attract publicity. Increasingly, reintroductions form part of wider discussions about rewilding, with the linked aims of restoring large areas of wildlife habitat together with some of the species that would, once again, be able to live there. Birds feature prominently in new proposals owing to their popularity. The UK Government recently threw its weight firmly behind the approach, with its 25-year plan for the environment emphasising the importance of species reintroductions (http://bit.ly/30wgEw7).
An increasing interest in reintroductions is broadly to be welcomed, although the approach comes with significant challenges. A range of issues must be considered, including the potential impacts on existing species and habitats in the release area, and on other interests such as farming. Here, I want to focus on one issue that is easy to overlook – that of deciding which species should be considered as native and so deserving of expensive restoration efforts.
The status of a bird is usually clear enough. There is no doubt that White-tailed Eagles, Red Kites and Corn Crakes were formerly widespread breeding birds in Britain. But for other species the lines are rather more blurred. Take the White Stork for example. There is evidence from place names and bone remains that storks visited Britain regularly in the past, as they do today (Gow & Edgcumbe 2016). But that is not the same thing as establishing that they were once regular breeding birds. In fact, although this is not an easy bird to overlook in the breeding season, the only historical breeding record in Britain is from the fifteenth century (in Scotland).
So, is the release of White Storks at the Knepp rewilding initiative in Sussex (and potentially another site in Norfolk) a reintroduction, or is it seeking to introduce a new breeding bird in southern England? If it’s the latter (and I suggest that it is), then is this something that should be welcomed unquestioningly or is it legitimate to ask if it is appropriate? Many birders take a relaxed view. The attractive White Stork is a scarce but regular visitor, and it might well start breeding naturally in future as climate change helps to create more amenable conditions. Where is the harm in giving it a helping hand? But, increasingly, there are also dissenting views, centred on a feeling that wildlife becomes rather less ‘wild’ when it is only present because of decisions taken by humans.
Already, a diverse range of non-native birds is well established in our countryside as a result of human interventions. Our bird biomass is dominated by the Common Pheasant Phasianus colchicus, while Canada Geese Branta canadensis, Egyptian Geese Alopochen aegyptiaca and Ring-necked Parakeets Psittacula krameri are increasingly widespread and familiar. Even undisputedly non-native birds have their supporters, as highlighted most clearly by opposition to the government-led cull of Ruddy Ducks Oxyura jamaicensis. But most conservationists would happily be rid of them. And it could be argued that the addition of White Storks to southern England is a further step towards ‘de-wildling’ rather than re-wilding the landscape, with the imposition of yet another new breeding species. Far from letting nature take its course to find out what happens next (an appealing central tenet of rewilding), the process is driven solely by direct choices made by humans about the species we would like to see.
There is a raft of new birds waiting in the wings as potential candidates for reintroduction (or introduction) to Britain. The White Stork projects have led to interest in its sister species the Black Stork C. nigra, and birds have already been brought together to establish a captive-rearing programme. This is another infrequent visitor to Britain and there are no previous breeding records; so if releases are undertaken, they could constitute another introduction of a new breeding bird. It is possible that they once bred naturally and were wiped out long ago, but this is no more than guesswork; the same applies to a large number of birds that we do not consider to be native to this country.
If a case can be made for White and Black Storks, then it can also be made for a wide range of high-profile birds that are irregular visitors or occasional breeders. Should we also be helping out the Black-winged Stilt Himantopus himantopus, Glossy Ibis Plegadis falcinellus, Little Bittern Ixobrychus minutus, Night Heron Nycticorax nycticorax, Purple Heron Ardea purpurea, Pallid Harrier Circus macrourus, Black Kite Milvus migrans, Eagle Owl Bubo bubo, Hoopoe Upupa epops and European Bee-eater Merops apiaster? Surely they have just as much right to be here as the storks? Some of these birds would be tricky to work with but techniques are improving all the time and release projects are far from implausible. If these birds are unable to colonise naturally in response to the changing climate, how would we feel about their imposition through the release of captive-reared birds? How much intervention is acceptable in order to facilitate or consolidate the spread of new species into Britain? Where should the lines be drawn to allow natural processes more of a role in future recolonisation events?
One reason why debate is urgently needed is the lack of effective legislation regulating the release of birds into the wild in Britain. Legal restrictions on releasing birds are patchy and inconsistent across countries within the UK and vary from species to species. As in many other areas of wildlife legislation, Scotland is one step ahead of the rest of the UK and has good legislation in place. But in England and Wales it defies credibility (and common sense) that while a licence is needed for the release of White-tailed Eagles, Red Kites and Cranes, none is required for the White Stork, Golden Eagle, Hoopoe or Bee-eater. The Black Stork and Black Kite are two of a number of birds that reside in an unhelpful grey area, with the need for a release licence hinging on whether or not they are considered to be ‘regular visitors’. The term is not defined in the legislation, leaving officials at Defra frantically scrambling to reach a consensus each time a new project proposal surfaces. The risk is that by the time that has happened, events on the ground will have rendered the discussion pointless. We do have a set of internationally respected guidelines on reintroductions (www.iucn-whsg.org/node/1471) but there is no legal obligation to follow them and projects can proceed having ignored them or, perhaps worse, paid lip service to them to gain a veneer of respectability, without taking the requirements seriously.
It is all too easy to voice concerns from the sidelines when individuals are working hard on projects they believe in passionately. I suspect that that is one reason why the Knepp White Stork project has received so little public criticism – together with the fact that in all other respects the rewilding of Knepp is such an inspiring project (Tree 2018). But in the absence of comprehensive legislation, the decisions taken by individuals and small captive-breeding centres have far-reaching consequences for all of us who enjoy watching birds and other wildlife. If nothing changes, the future composition of our ‘natural’ wild bird communities will, increasingly, be influenced by experts in captive-breeding, some of whom are becoming ever more ambitious in their aims, and less and less by chance events and natural processes. Whether that is seen as a good thing will depend on your point of view and your individual philosophy towards wildlife.
I am grateful to Matt Heydon and Ian Newton for providing helpful comments on an early draft (the views expressed remain entirely my own).
Carter, I. 2019. The Red Kite reintroduction: 30 years on. Brit. Birds 112: 422–426.
Gow, D., & Edgcumbe, C. 2016. A history of the White Stork in Britain. Brit. Wildlife 27: 230–238.
Tree, I. 2018. Wilding: the return of nature to a British farm. Picador, London.
Ian Carter took early retirement in 2016 having worked as an ornithologist for Natural England for 25 years.