Areas The Red Kite example essay topic

CRITICAL REVIEW OF THE POPULATION STATUS OF THE RED KITE Milvus milvus Introduction The Red Kite is one of Europe's most threatened birds of prey. Numbering 11000-13000 pairs, this species is patchily distributed, comprising several populations, some of which have recently suffered major bottlenecks, (May CA, 1993). The Red Kite is a large bird of prey, its body is rusty chestnut-brown with a paler golden to white head with dark streaks. Its characteristic forked pale chestnut tail most easily distinguishes the Red Kite. The Kites legs are bright yellow, as are its eyes and black-tipped beak, (web).

Although the Red Kite dose not feature on the red list of endangered species Red Kite populations have showed declines during the 20th century, as a result of human pressure and changes in land use. The decline in the European population has been reflected within the UK where intense persecution over the past 200 years led to the extinction of the majority of the population. Distribution The Red Kite is globally confined almost to Europe. Remnant populations in western Asia and North Africa are virtually extinct, while populations in south and east Europe are also declining and fragmented. It is only in north-west and central Europe that numbers are stable or recovering. In the northern and eastern parts of the range (Sweden, Poland, Germany, Belarus and Ukraine) the Red Kite is migrant, moving south and west to winter in southern Europe, especially around the Mediterranean Basin, (Summers RE 1997).

Within the UK, Red Kites were once widely distributed, but persecution, especially in the 19th century, led to the native breeding population being restricted to central Wales. More recently, because of intensive protection measures in the 20th century, Red Kites are slowly expanding through Wales again. Recent and ongoing re-establishment programs have resulted in new populations in southern England, and northern Scotland and more recently in central and northern England and central Scotland, (web). Survey methods Popular and commonly used methods for the surveying of Red Kites are the use of road transects, the counting of roosts of breeding populations, nest searching, and the counting of territorial pairs. A paper by (Vinuela J 1997) reported the reliability of road transects as a census method for wintering and breeding Red Kites.

Road transect data were compared with censuses of wintering populations made by roost counts and breeding populations made by a combination of nest searching and detection of territorial pairs. The variation in population density explained a high percentage of the variance of abundance indices provided by road transects during winter ( 90%) and breeding seasons (85%). The estimation of densities from distances to the transect did not provide more accurate results than unadjusted counts. On the contrary, skip counts may consistently bias population estimates in species that are attracted by roads, or may provide unpredictably unrealistic results when the number of observations is low. Winter roost counts made in areas of high breeding density apparently underestimated the real populations, because resident Red Kites usually do not use roosts, and this was detected through the results obtained in road transects. No clear effect was found of forest cover on the delectability of Red Kites, probably due to their selection of open areas for hunting.

Road transects seem to be a reliable method to estimate numbers of Red Kites. Population structures and trends The European population is currently estimated at 17,394-28,185 pairs. Other than a few in the Canary Islands, the Cape Verde Islands, in north west Africa, and possibly in western Transcaucasia, this amounts to the whole world population, (Stor ass T, Wedge P, 2001). The Red Kite is one of the relatively small number of birds of prey on the IUCN (International Union for the Conservation of Nature) Red list of endangered species. The list covers all flora and fauna and classifies entries as Endangered, Threatened, Vulnerable, Rare or Insufficiently Known. The Red Kite falls into the last category.

In 1984 the world population was estimated to be not much more than 15,000 pairs, (web). In certain parts of the Red Kites range the birds have become extinct, such as in Britain in the past, however birds have been reintroduced and populations are increasing, however in other areas the Red Kite is verging on extinction. A paper by (Hille S, Thiol lay JM 2000) reported that extinction of the Red Kite on the Cape Verde archipelago was imminent. In 1996 and 1997, the first census of the Kites on the entire archipelago revealed that fewer than 10 individuals of the species still existed. As expected from the first survey, the tiny population of Kites further declined and only two individuals were found in 1999. The population is expected to become extinct very soon.

The presumed cause of extinction was indirect poisoning, lack of food, changes in landscape, and human persecution. A paper by (Hille S 1998) Reported that while distributed to three islands in the 1980's the Red Kite Milvus milvus, is now only found on Santo Ana to, the Westernmost island. There is no evidence of breeding from any of the Kites. Europe south of the 60th Parallel (southern Sweden). A realistic world population of 22,500 pairs at the start of the last decade (1900 - sadly these figures must be probably be revised downwards) distributed roughly as follows: (Birdlife in Europe 2001) Germany - 9,200 to 12,000 Spain - 3,000 to 4,000 France - 2,500 to 3,000 Switzerland - 800 to 1,200 Sweden - 700 to 800 Poland - 500 to 600 Great Britain - 250 to 300 Italy - 150 Figures represent pairs of breeding Red kites. The Red Kite has declined across most of its European range, even in the bird's stronghold of Germany.

In Germany, where 60% of the European population was found, the overall population declined 255 from 1994 to 1997 alone. Near Halberstadt, a population of at least 230 pairs was down to 35 in 2000, (Schreiber A, Stubbe M, Stubbe A, 2000). In north eastern France, where about 2/3 rds of the French breeding population was found, it has drastically declined everywhere (Alsace, Lorraine, Franche Comte) and even disappeared from large areas (Champagne-Ardennes). Recent reports from other areas indicate that the population, once considered to be safe, now shows signs of decline. The steady downward trend of the number of migrants counted through the Pyrenees (Orambideska) is a reliable indicator of this general evolution of the European population, (Hancock M, Gibbons D, Etheridge B, Sheperd M, 2000).

In Spain, reports of declines come from most provinces, involving both breeding and wintering populations. It has even disappeared from large protected areas such as the Don anan National Park, where it was numerous and well studied. On the island of Minorca, a 1989 census gave 140 individuals, whereas in 1998 only 4 breeding pairs were found. In Italy, where it was once found almost throughout, its distribution has now shrunk to only 5 small populations, the largest one in the Apennines (150 pairs).

The decline was equally sharp in Sicily, where 15-25 pairs survive thanks to the sustained conservation action, (Hancock M, Gibbons D, Etheridge B, Sheperd M, 2000). Other European countries harbour relatively minor populations. Denmark, for instance, was recolonised in 1976 and the population peaked at 25 pairs in 1993 but halved shortly after and was always low and unstable, with poor breeding success. Austria was also recolonised in the 1980's, soon reaching 5-10 pairs that are now reduced to 0-2 along the eastern border. Two small countries still hold an apparently stable, but no longer increasing, population: southern Sweden and Switzerland. Great Britain is an exception; after 15 years of an aggressive re introduction program the small surviving Welsh population was reinforced by several English and Scottish new populations and the total number of breeding pairs in the country as a whole now exceeds 350, (Evans IM, Summers RW, O'Tool L, Orr-Ewing DC, Evans, Snell N, Smith J, 1999).

Legal protection since the 1950's, and the reductions in the use of DDT and other organochlorine compounds from around 1970, made recovery and resettlement of Red Kites possible in both Britain and the Netherlands, (Lensing R, 1997). Re-establishment programs in other parts of the UK were initiated in 1989 and 1998 the re-established populations in southern England and northern Scotland 100 pairs. In an attempt to extend the breeding range of the Red Kite within the United Kingdom, 93 (48 males and 45 females) juvenile Red Kites, originating from Spain, Sweden and Whales, were released in southern England. In 1989-94, and 93 (52 males, 40 females) juvenile Red Kites, originating from Sweden, were released in northern Scotland in 1989-93. Minimum estimates for first year survival were 83.1% and 78.0% for male and female Red Kites in England, and 50.0% and 52.5% in Scotland, respectively. Annual survival improved in the second and third years.

Several sick or injured birds were recaptured and returned to the wild. Successful breeding started in 1992 in England and Scotland. There was a minimum of 59 clutches laid in England and 29 in Scotland in 1991-95. Clutch size averaged 2.9 (England) and 1.6 (Scotland).

Demographic parameters were used to construct deterministic models for population growth. At current rates of growth, it is predicted that the English and Scottish populations will exceed 100 breeding pairs by 1998 and 2007, respectively, (Evans IM, Summers RW, O'Tool L, Orr-Ewing DC, Evans, Snell N, Smith J, 1999). A report by (English nature magazine 1999) reveals that Red Kites are making a comeback in Yorkshire after more than a centuries absence, signalling the latest advance in the English Nature Species Recovery project to reintroduce the birds throughout England. The Re-establishment programme is looking good in both the earlier re- introduction's areas, the Chiltern's and the Midlands. The southern population, now numbering at least 75 pairs. Threats Poisoning, in recent years there have been increases in the number of incidents of Kites being killed by eating poisoned rats, a new generation of highly toxic rodenticide's are to blame, (English Nature magazine, 1996).

The decline of the Red Kite across its European range may be can be attributed to several aspects associated with habitat changes, such as in Wales (Newton I 1996) afforestation of the Welsh uplands might affect Kites adversely, by reducing the area of open foraging habitat. At present, only 16% of the total area used by Kites in Whales is under trees. Habitat quality is ultimately the main influence that determines weather Kites can breed and how well they breed, (Evans IM, 1998) this has been a major influence on the decline of the species throughout Europe over the past decades. Man has altered large tracts of the bird's habitat; as a result the species distribution has been altered. Conclusion The Red Kite a species which has showed a decline in its population over almost all of its European home range.

Extinction of the Red Kite in the UK was only prevented by an intensive programme of protection work and the re introduction of the species to other parts of the country. The Red Kite is a species, which requires national monitoring to enable conservation groups to ensure the birds survival. If the Red Kite continues to decline in the same way that it has over the past century populations species may become extinct in certain areas of its range.