World status of the Red Kite A background to the experimental reintroduction to England and Scotland Ian M. Evans and M. W. Pienkowski n 1989, the Nature Conservancy Council (NCC) and the Royal Society Ifor the Protection of Birds (RSPB) started a joint experimental programme to re-establish the Red Kite Milvus milvus in its former range throughout Britain. This followed a long period of detailed assessment by the NCC and the RSPB as to the desirability and practicality of such a project. It also followed the collaboration of these and other organisations in reintroducing the White-tailed Eagle Haliaeetus albicilla to Britain, a project which has now achieved all its early targets. The purpose of this paper is to set the context for this programme by reviewing the Red Kite's world status; outline the features to be considered before embarking on a reintroduction programme; and summarise progress so far. Historical status The Red Kite was formerly common throughout Europe. During the nineteenth century, it inhabited the area now covered by Italy, France, Switzerland, Germany, Denmark, Sweden, Norway, European USSR, the Netherlands (although rather rare), parts of north Africa, Siberia and 'the greatest part of Asia' (Morris 1904), although the last is perhaps rather sweeping. In Britain, it was said to have 'swarmed in the streets of London' in the fifteenth and sixteenth centuries (literature quoted by Nisbet 1959) and was protected by legislation on account of the cleaning benefits of its scavenging habit. More recently, the geographic range (fig. 1) was described by Walters Davies & Davis (1973) as extending north from Iberia, through southern and eastern France and Germany to southern Sweden. It extended eastwards as far as the western Soviet Union, from the Baltic Republics in the north to the Balkans and the Caucasus in the south. Within this range, the distribution was rather fragmented, since it was absent from most of [Bri(.fimfc84:171-187,Mayl991] 171 172 World status of the Red Kite Fig. 1. World distribution of Red Kite Milvus milvus, reproduced from Cramp & Simmons (1980, The Birds of the Western Palearctic, vol. 2), by kind permission of Oxford University Press. RED = breeding distribution; GREY = winter distribution southern Poland, Czechoslovakia, eastern Switzerland, Austria, Hungary, Denmark, Norway, Belgium, the Netherlands and northwestern Germany. Outside Europe, populations survived in parts of northwestern Africa and in the Canary and Cape Verde Islands. The northern breeding popula­ tions (with the exception of those in Britain) are mainly migratory and winter in the Mediterranean area. In recent years, however, increasing [A donation from ZEISS Germany has subsidised the inclusion of fig. 1 in colour] World status of the Red Kite 173 numbers of individuals have remained in Sweden and Germany through­ out the year (see also Cramp & Simmons 1980). The decline in the abundance of the Red Kite during the nineteenth century has been attributed mainly to human persecution. To some extent, this continues today, despite legal protection. As a consequence, this species is rare over much of its present range, and it is considered vulnerable in world terms. It is one of three British species on the World Checklist of Threatened Birds (Collar & Andrew 1988). It has been given protection under Annex 1 of the EEC Bird Directive, Schedule 1 of the Wildlife and Countryside Act 1981, and the Berne and Bonn Conventions. This legal protection (and in some cases physical protection of nest sites) has been beneficial, since it has halted the decline in several countries and encouraged some recovery of range. In Britain, such measures have allowed the small remnant of British Red Kites in Wales to increase and expand in range slightly. Low breeding productivity, however, partly caused by egg-collecting, and illegal poisoning remain problems in Wales (see below). Present status In the past, there have been few attempts to census the entire world population of the Red Kite. Recently, Meyburg & Meyburg (1987) assessed the status of raptor populations in countries bordering the Mediterranean, whilst Gensb0l (1986) has covered the Western Palearctic. In a number of areas (e.g. Wales, Sweden, Belgium, Denmark and Corsica), regular monitoring has meant that the population status is relatively well known. In many others (e.g. mainland France and Germany), however, only rough estimates can be made, whilst in the rest (e.g. Morocco and the USSR) quantitative data are lacking. We sent requests for information to ornithologists in all countries in Europe, North Africa and the Middle East where Red Kites were thought to have bred or wintered in relatively recent years. Contributors were asked to provide recent information on the actual number of breeding pairs in their country as well as recent and past population trends. A literature survey was also undertaken. The results of the review are given below and breeding aspects summarised in table 1. This can be viewed against the distribution map reproduced from Cramp & Simmons (1980) in fig. 1. In order to aid identification of patterns of change, the review below is ordered approximately geographically. We have tried to minimise breaks in the list where the distribution is fairly continuous. To do this, we start in the northwest, and proceed eastwards across central Europe, south­ wards to the Mediterranean, and finally westwards to Iberia and the Atlantic islands. NORWAY There have been no breeding records this century, although apparently there was a very small population in the county of Ostfold up to about 1880. The species has remained a rare visitor. There has, however, been a marked increase in the number of records in recent years, with three to four annually. These birds are probably from Denmark or Sweden (Geoffrey Acklam in litt.). 174 World status ofthe Red Kite SWEDEN Since the early 1970s, the population in the south has increased steadily. By 1980, there were 50 pairs, of which 42 were successful, and, in 1981, 54 pairs, of which 49 were successful (Svensson 1982). By 1986, the population had increased three-fold, to 150 pairs (Sylven 1987), and, by 1989, to over 200 pairs. Productivity has been estimated at 1.98 young per successful pair and 1.54 per territorial pair (Magnus Sylven, Roy Dennis in litt. and verbally). DENMARK The large population of Red Kites was exterminated at the turn of this century, but breeding was occasionally attempted between 1920 and 1970. During the 1970s, the species returned as a regular breeder. Only 10-15 pairs have become established, breeding annually during 1980-89, mainly in southeast Jutland (Hans ErikJorgensen in litt,). Breeding success ranges from 53-63% of nests in the core area of southeastern Jutland to more than 50% in other areas. An average brood size of 2.1 young from a total of 54 successful nests has been recorded (Jorgensen 1989). BRITAIN & IRELAND Formerly bred in every county, but during the nineteenth century relentless persecution exterminated this species from England, Scotland and Ireland. Only a small remnant group of approximately 12 individuals survived in the more remote parts of mid Wales. This population has, as a result of nest protection, increased very slowly up to the record level of 69 territorial pairs (of which 52 actually nested and 32 fledged young) in 1989, and 62 nesting pairs producing 70 fledged young in 1990 (P. E. Davis in litt. and verbally). Before 1980, almost all the known breeding was confined to an area of about 70 X 45 km in mid Wales (Davis & Newton 1981). Since 1981, the population has expanded slightly outside this area. Recolonisation of former haunts is, however, continually hampered by the illegal use of poison baits and to some extent by the destructive practice of egg-collecting. The productivity during 1951-80 was notoriously poor, with, on average, only 0.54 young per territorial pair. This is equivalent to 0.66 young per nesting pair and 1.34 young per successful pair (n=676). During 1964-80, mean clutch and brood sizes of 2.20 and 1.35 respectively were recorded, and only 40% of all nests fledged young (Davis & Newton 1981). Recent breeding statistics for 1985-89 indicate that productivity has remained around these levels (P. E. Davis in litt.). FRANCE Thiollay & Terrasse (1984) estimated 2,300-2,900 pairs in 1979-82. No more-recent survey has been undertaken for the whole of France. The main breeding areas for the Red Kite in 1982 were Lorraine (740-790 pairs), Franche-Comte (700-1,000 pairs), Champagne- Ardenne (480-550 pairs) and Midi-Pyrenees (800-1,000 pairs). Smaller populations are also found in the Massif Central, Auvergne and Burgundy. Recent estimates are 400 pairs in Franche-Comte (Atlas da Jura by Joveniaux et al., cited by Dr J. Francois in litt.) and 100 pairs in the Haute-Loire, Auvergne (Bernard Joubert in litt.). In Champagne-Ardenne, the large population appears to have decreased in the last five to seven years; this is thought to be related to habitat loss and increased cultivation. Many winter roosts have also disappeared in this region; this has been attributed to successive cold spells and a decline in refuse dumps. In Champagne, Red Kite productivity of 1.51 young per breeding pair and 1.86 young per successful pair has been recorded from 53 occupied nests in 1971-82 (Christian Riols in St). Poisoning, both legal and illegal, is the main form of persecution and can occur on a very large scale. For instance, a plague of voles (Microtinae) led to a poisoning campaign over 150,000 ha in southeastern Haute-Marne, one of the best areas for birds of prey in northeastern France. Also, in the western part of Marne department, raptors are still poisoned, trapped and shot despite legal protection: the Red Kite is the most vulnerable species (Christian Riols in litt.).