Interview with Ian Carter about the Red Kite in the UK

Date of the interview: 06 September 2010

In this interview Ian Carter, an ornithologist from Natural England talks about the current situation of the Red Kite in the UK. Ian is one of the leading experts on the Red Kite in Europe and author of a popular and highly praised monograph on the Red Kite (The Red Kite, 2nd edition, 2007, Arlequin Press, ISBN 9781905268030). He is currently working on a book about bird reintroductions in Britain for the Poyser series.

Markus Jais: What is the current status of the Red Kite in the UK?
Ian Carter: The Red Kite population is increasingly rapidly in the UK thanks to the continued recovery of the Welsh population and reintroductions into various parts of England, Scotland and Northern Ireland. In addition, a reintroduction into the Republic of Ireland is currently being undertaken.

Ian Carter

Ian Carter

Markus Jais: How has the population developed during the 20th and 21st century?
Ian Carter: This species was once one of the UK’s most widespread and abundant birds of prey. It would have been a regular sight in both rural areas and in some of our major towns and cities. It declined as a result of improved standards of hygiene in urban areas and direct human persecution in the countryside. At one time, anything with a hooked beak and talons was regarded as a threat to livestock and gamebirds and persecuted relentlessly. The Red Kite, being a scavenger, and not especially wary of humans, was especially vulnerable and poison baits, traps and shooting accounted for large numbers of birds. The low point was reached in the early decades of the 20th century when only a handful of breeding pairs remained in the remote uplands of central Wales.

There has been a steady increase in the Welsh population over recent decades. At first this was rather slow and there were still only around 30 pairs by the early 1970s. In recent years the population has increased more rapidly, due to much reduced levels of persecution. There were over 100 pairs by the mid-1990s and an estimated 900 pairs by 2009. The Red Kite has now been reintroduced at eight different sites in England and Scotland with an estimated population of 800 pairs in England and 150 pairs in Scotland by 2009.

Markus Jais: How important was the reintroduction program for population growth?
Ian Carter: This programme has been very important for restoring the Red Kite to England and Scotland. Since the programme started back in 1989 the population has gone from being completely absent to an estimated 950 pairs in the two countries. The Welsh population has now spread just over the border into western England but this involves only a very small number of pairs. Without the reintroduction programme the species would still be very rare outside of Wales.

Markus Jais: The population in Scotland grows more slowly than the one in England. What are the reasons for this?
Ian Carter: The very obvious discrepancy between the reintroduced populations in England and Scotland is the result of far higher levels of human persecution in Scotland, much of it associated with the management of upland grouse moors for recreational shooting. The contrast is most apparent when considering the first release projects which took place in the Chiltern Hills, southern England and the Black Isle, northern Scotland. Although the same numbers of birds were released over the same period, and levels of breeding productivity are very similar, the Chilterns population has increased to over 600 pairs whilst the Black Isle population has increased only very slowly to around 50 pairs. This is a very clear demonstration of just how much damage can be done to raptor populations through human persecution even today.

Two young Red Kites from central Spain in their release pen in central England in the mid-1990s.

Two young Red Kites from central Spain in their release pen in central England in the mid-1990s.
© Ian Carter

Markus Jais: What is the preferred habitat of the Red Kite in the UK?
Ian Carter: Work on Red Kites in the UK has shown that it is a very adaptable, generalist species, able to do well in a wide range of different habitats. All it requires are open areas where it can forage for food and at least some woodland habitat to provide nesting and roosting sites. For example, central Wales is an upland area with a damp, cool climate and large areas of rather unproductive grassland and moorland. This has resulted in very low levels of breeding productivity for Red Kites but has not prevented the population from increasing in recent decades. In central England open habitats in the release area are dominated by intensive arable farmland with only a low proportion of grassland. Despite this, the population has increased rapidly and enjoys a high level of productivity. Based on what we have seen so far, we expect the Red Kite to eventually spread to a very high proportion of the available countryside in the UK. Only the highest upland areas and perhaps a few areas of low-lying fenland with few trees may not be able to support this species, or perhaps will support only very low densities.

Markus Jais: Is there competition with other raptors like Common Buzzards?
Ian Carter: Although this has not been quantified, it is likely that there is some competition between these two species as there is considerable overlap in the diet and foraging behaviour. The two species can, of course, coexist and they are often found together in the same areas but it is likely that either species would reach a higher breeding density in the absence of the other. The two species often nest in the same blocks of woodland and there can be some aggression between them in the breeding season. Cameras set up at Red Kite nests have even shown Buzzards attacking young Red Kites in the nest although this is not thought to be common. It is likely that there is also competition for animal carrion between Red Kites and other species, primarily Magpies, Carrion Crows and Ravens. Elsewhere in Europe it is thought that there may be some competition between Black and Red Kites, although again, this is difficult to quantify.

Markus Jais: What is the preferred food of the Red Kite in the UK? Is there enough suitable prey?
Ian Carter: The Red Kite is the ultimate generalist raptor and studies of the diet in the UK have shown that it will scavenge on a very wide range of different prey. Small and medium-sized birds and mammals are taken regularly with Rabbits, Brown Rats, Woodpigeon, Pheasants and Red-legged Partridges forming a significant part of the diet in many areas. Large mammals are also scavenged and Sheep carrion is an important food in Wales. As with the Buzzard, earthworms can form an important component of the diet and Red Kites are often seen flying low over damp grasslands, dropping down to feed on earthworms on the surface of the field. The majority of bird and mammal food is taken as carrion although some live prey is also taken. For example, young pigeons and crows are sometimes snatched from their nests.

Markus Jais: How does illegal poisoning and shooting affect the Red Kite?
Ian Carter: As mentioned above, illegal persecution remains a problem for the Red Kite, particularly in parts of Scotland where it has prevented reintroduced populations from becoming more firmly established. As a scavenger, it is especially susceptible to the use of illegal poison baits and because it is a highly social species, a number of birds may be killed by the same bait. In many cases these illegal baits are probably aimed primarily at other species such as Foxes or crows but the Red Kite is often affected. Shooting and trapping also still occur although only at relatively low levels.

Two young Red Kites killed by an illegal poison bait in central England.

Two young Red Kites killed by an illegal poison bait in central England. The Brown Hare carcass had been laced with the highly toxic agricultural pesticide carbofuran and left out in the open. A third dead Red Kite and two dead Buzzards were found nearby. Illegal persecution remains a problem for birds of prey even in the 21st century.
© Ian Carter

Markus Jais: How do wind farms affect the species?
Ian Carter: There have been a small number of Red Kites killed by wind turbines in Wales and Scotland in recent years. Based on current information and the existing densities of windfarms in the UK, this is not thought to be a major threat to Red Kite populations.

Markus Jais: What are the other threats to the Red Kite in the UK?
Ian Carter: Accidental secondary poisoning by highly toxic second-generation anticoagulant rodenticides and by lead is known to kill large numbers of Red Kites in the UK. The rodenticides are ingested when feeding on rodents killed by poison and, being persistent, can build up to lethal levels. In some cases, the poisons used are so toxic that just a single rodent body may be enough to deliver a lethal dose. Publicity campaigns to encourage the use of alternative methods of rodent control and to use poisons with care have been undertaken to try to minimise the dangers.

Secondary poisoning by lead occurs when Red Kites scavenge on pest or game species that have been killed by lead ammunition, mainly from shotgun cartridges. A recent study found that 14% of Red Kites found dead in England had lead levels in their tissues sufficient to have caused their death. Whilst lead has been banned from use over most wetlands and for killing waterbirds it remains in common use in terrestrial habitats with consequences that are largely unseen unless specific studies are undertaken.

Small numbers of birds are killed by collisions with road vehicles and trains, or electrocuted on powerlines but these are not sufficient to represent a serious threat to populations.

Markus Jais: Why do you think the population in the UK is doing much better than in many other European countries?
Ian Carter: There has been considerable discussion about this point in recent years and, it is fair to say, some differences of opinion between Red Kite workers in different countries. My personal view is that the Red Kite is such an adaptable and generalist species that, in the absence of human persecution or accidental poisoning, it is able to do well in the majority of landscapes across Europe. We have seen this in the UK where it has increased rapidly in unproductive upland habitats on the western fringes of Europe in Wales, and has also done very well in parts of lowland England dominated by intensively managed arable farmland, reaching very high densities. There are very few areas of Europe that would not be capable of supporting this species. That is the good news!

The downside is that because the Red Kite is primarily a scavenger, and is not afraid of foraging close to farms and other human settlements, it is extremely vulnerable to human persecution, especially the use of illegal poison baits, and accidental secondary poisoning. Others factors, such as the intensification of farmland, may of course make the countryside less suitable for birds like the Red Kite and result in reduced breeding densities. But where recent declines have been rapid or where the species has been reduced to very low levels or even become extinct, I believe that more direct human factors, primarily poisoning, are to blame. Because the Red Kite is partly a migratory species these factors may affect breeding populations even in areas where persecution is not a serious problem. Continued problems with high numbers of poisoning cases in Spain, where most of the central European Red Kite population winters, remains a major concern. This is the single greatest threat to the Red Kite in Europe and something that the largely resident populations in the UK have not been subjected to.

Markus Jais: Should the reintroduction programs continue or is the population capable of growing on it's own?
Ian Carter: In England and Scotland the Red Kite population should now be able to increase and spread without further human assistance. Although there is still one active project in the north-west of England where releases are ongoing, there are no further plans for any more release projects. Some people are rather suspicious of reintroduction projects and believe that they represent unnecessary human interference and meddling with a species. Hopefully these views will become less strongly held as the population continues to increase and spread naturally with no further need for human interference. I believe that reintroductions should only be instigated when there is a clear need for human intervention and natural recolonisation has little chance of restoring the population within the short or medium term.

In Northern Ireland and the Republic of Ireland the reintroduction process is still in its early stages and further release projects may be needed to secure the future of the Red Kite in these countries.

Young Red Kite being released in Northamptonshire, central England in 1996.

Young Red Kite being released in Northamptonshire, central England in 1996.
© Ian Carter

Markus Jais: Where did the reintroduced Red Kites come from?
Ian Carter: The reintroduction programme in the UK has been a truly international effort and the contributions made by those who helped to provide young birds should not be underestimated. Birds released in England in the early years came mainly from northern and central Spain, with birds released in Scotland coming mainly from Sweden in the early years and later from Germany. More recently it has been possible to take young birds from the well established reintroduced populations for release in other parts of the UK. Birds released in Ireland have been sourced from the expanding Welsh population.

Markus Jais: What do you recommend to other conservationists who want to reintroduce raptor species into places where they have gone extinct?
Ian Carter: I think that reintroduction is a very valuable conservation technique but should only be used when the conditions are right and when it is really necessary. Natural recolonisation is preferable (and far less expensive!) and should be allowed a chance if it may result in the restoration of populations within a reasonable period of time. When reintroductions are undertaken it is vital that they are well planned and resourced so that the released birds can be monitored and any remaining threats identified and tackled. If the factors that lead to extinction in the first place are still operating then a reintroduction will not succeed. The internationally agreed IUCN guidelines for reintroductions are an essential starting point for anyone considering a new reintroduction project.

Markus Jais: What can birdwatchers and other people do to help the Red Kites?
Ian Carter: It is always useful to receive sightings of birds in areas where they were previously absent or rare, especially breeding records or records of communal winter roost sites. Birdwatchers can also play a useful role in raising awareness of the threats still faced by the Red Kite and other birds of prey. Dead birds should be reported to the authorities so that they can be sent for analysis and any suspicious dead animals that may be poison baits should also be reported. Birdwatchers can also help by discussing threats such as anticoagulant poisons and lead ammunition with local farmers and landowners.

Markus Jais: How do you see the future of the Red Kite in the UK?
Ian Carter: The future for the Red Kite in the UK is very bright. Whilst unnecessary deaths have slowed things down a little, the Red Kite is still increasing rapidly in most areas. Despite this, the rate of spread to new areas has been rather slow for two main reasons. Firstly, this species is able to breed at very high densities (more than 50 pairs/100km2) so it takes a long time for the immediate areas close to the release sites to become saturated. Secondly, the Red Kite is a highly social species and individuals are usually reluctant to settle to breed in new areas away from existing populations. These factors help to explain why the Red Kite is still absent from many areas of the UK and elsewhere in Europe, despite the presence of perfectly suitable habitat.

Markus Jais: What is the status of the Black Kite in the UK?
Ian Carter: The Black Kite is a rare but increasing summer visitor to the UK with the occasional bird overwintering. There has been at least one record of a Black Kite, paired to a Red Kite, breeding successfully in northern Scotland. With further climate change likely, it is always possible that it could become established as a regular breeder but there are no signs of this happening just yet.

Markus Jais: What was your most amazing experience with Red Kites?
Ian Carter: I will never forget the visits to Segovia, Salamanca and Valladolid in central Spain to collect young birds for release in central England in the mid-1990s, and the huge amounts of generous help received from fieldworkers, foresters and the government authorities there. This helped to the central England reintroduction project possible. Cooperation and help from others in Spain, Wales, Sweden and Germany has been essential for the other reintroduction projects in the UK

I am fascinated by the communal roosting behaviour of the Red Kite and have regularly watched up to 100 birds at their main roost in central England. I’m always amazed by the variation in behaviour at these roost sites depending on the local weather conditions. A strong wind often results in birds indulging in spectacular aerial displays before they finally settle in the trees to roost. In contrast, on cold, still evenings the birds tend to glide towards the roost purposefully, often heading straight for the roost wood or nearby isolated trees where they gather to perch. Flight is clearly less onerous for these birds in windy conditions and the result is often spectacular.

Markus Jais:Ian, thank you very much for the interview.