Waterfowl at risk JANET KEAR and GWYN WILLIAMS This review of the waterfowl group Department. Appendix 1 (Endangered) con­ (Anseriformes) gives brief accounts of why tains animals that were considered by species or subspecies are considered to be delegates at the original Convention to be endangered, present numbers if known, threatened by extinction and which are or avicultural history, and any recent conserva­ may be threatened by trade, and Appendix 2 tion projects or proposals. The two main (Vulnerable) contains those that, although sources of information on which animals are not at the moment threatened with extinc­ believed to be at risk have been the Red tion, might become so unless trade is Data Book, and the Washington Conven­ regulated. Appendix 2 also contains the so- tion. In addition, we have included those called ‘look-alike’ species: those not island forms with small populations that, threatened themselves but being so similar although not endangered at present, could to a threatened species that they are included decline suddenly due to loss of habitat, dis­ to aid enforcement. Most contracting coun­ turbance, the introduction of predators, or tries have adopted legislation that controls natural disaster. the import and export of Appendix 1 birds Classification, and therefore the definition fairly tightly, but merely ‘records’ such of species and subspecies, follows A movements for Appendix 2 species. Coloured Key to the Wildfowl of the World, The bird lists of the Washington Conven­ by Peter Scott (1968 edition), except where tion already need revision, and do not always the Red Data Book or the Washington agree with the Red Data Book. In general, it Convention differ from this. Where more re­ is likely that species will be added to the lists cent taxonomic work has questioned the requiring licences rather than removed. The validity of one or two subspecies, particular­ United Kingdom Government has, indeed, ly of geese, this is noted in the appropriate now subjected the majority of animal species place in the text. to licence. List A in the British Endangered The Red Data Book (RDB) Vol. 2: Birds, Species (Import and Export) Act 1976 is compiled and currently being revised by the equivalent to Appendix 1 of the Washington International Council for Bird Preservation, Convention and contains those species that is a guide to those birds that are rare and in are considered seriously threatened. All danger of extinction. Its purposes are to other waterfowl are on List B (equivalent to draw attention to their plight and to provide Appendix 2) with the exception of domestic the information necessary to influence their forms of the Mallard, Muscovy Duck, future. Four headings categorize their status: Greylag and Chinese Goose. Endangered—birds in danger of extinc­ tion and whose survival is unlikely if the causal factors continue operating. Cuban Whistling Duck Dendrocvgna Vulnerable— birds believed likely to move arborea ( Figure 1). into the endangered category in the near RDB Vulnerable future. WC Appendix 2 Rare— birds with small world populations that are not at present endangered or Has declined throughout its range, especially vulnerable, but are at risk. in the last 40 years, possibly due to the in­ Indeterminate— birds that are suspected troduction of the Indian Mongoose of belonging to one of the above categories Herpestes auropunctatus (in 1872 into but for which information is lacking. Jamaica, from where it spread to many The Washington Convention on Inter­ Caribbean islands), excessive shooting, and national Trade in Endangered Species of the collection of eggs for food. More recently, Wild Fauna and Flora (WC in this paper, its habitat (freshwater and brackish swamps) but also known as CITES) was signed in has been partly destroyed by drainage, par­ Washington, USA, in March 1973 by over ticularly in the Greater Antilles. 30 countries, including the United Kingdom. In Cuba and Hispaniola, it is described as It lists ‘Endangered’ species in two appen­ common, but declining. It is still resident and dices, and licences to import or export listed reasonably common on the Cayman Islands birds, and certain bird products, have to be and in the Bahamas; on Inagua and possibly obtained from the appropriate Government Andros, there is a small but secure popula­ 5 Wildfowl 29(1978): 5-21 6 Janet Kear and Gywn Williams Figure 1. Range ofCuban Whistling Duck tion. In Puerto Rico it was thought to be aviculture were felt to be unacceptably high; very rare, although a flock of 80 birds was however, there seems no recent evidence that found in 1970 in the north-east of the island. large numbers of either have been imported It has not been seen in Jamaica since 1960 into North America or the United Kingdom. (W. King, pers. com.). Numbers in the wild are not known, so Hunting is prohibited in the Bahamas, counts of both species are required. The Cuba, Puerto Rico, the Virgin Islands and Black-necked Swan breeds fairly readily in Jamaica, although enforcement is generally captivity, but the Coscoroba much less so. non-existent, except in Puerto Rico. It is sometimes shot on Cuba, where it occurs Bewick’s Swan, Western race Cygnus colum­ with the Fulvous Whistling Duck D. bicolor, bianus bewickii a species that may be legally hunted, and is said to be something of an agricultural pest. Whilst the total number of this race is It is not protected on Hispaniola, although a probably as high as it has ever been closed hunting season during the species’ (estimated to be at least 10,000 individuals), breeding season has been proposed in the the population is still small and vulnerable. Dominican Republic (W. King, pers. com.). Although legally protected throughout its It is widely represented in waterfowl range (apart from Poland, where the Mute collections throughout the world, and breeds Swan C. olor is protected and the Bewick’s is freely in captivity (although it is not par­ thought to benefit from this), X-ray examina­ ticularly hardy in the northern winter). It is tion has shown that 44% of the adult popula­ thus a species that might benefit from captive tion carries at least one lead shot-gun pellet rearing and re-introduction into areas, es­ (Evans et al. 1973). pecially islands, where hunting could be con­ The swan breeds in northern Siberia trolled and the mongoose is rare or can be between the Pechora delta and the Lena exterminated. delta, an area that is likely to be increasingly disturbed by, for example, the search for oil, and by projects such as the reversal of the Coscoroba Swan Coscoroba coscoroba Rivers Ob and Yenesi to irrigate the desert Black-necked Swan Cygnus melanocoryphus areas of central USSR. In such cir­ cumstances, reserves may have limited value, WC Appendix 2 since the swans breed far apart and the areas required would be vast. Listed in the Washington Convention ap- In the winter, Bewick’s Swans migrate to prently because numbers exported from the Germany, the Netherlands, Britain and wild in South America for the purposes of Ireland. They traditionally feed on wet Waterfowl at risk 1 pastureland, a habitat fast disappearing 2,848 were counted in 1968 and 3,400 es­ through drainage, and there has been con­ timated as a minimum figure, and readily siderable alteration in the distribution of this enough conserved to be no longer swan within its wintering range (for exam­ threatened. In February 1975, the US Rocky ple, the last twenty years have seen decreases Mountain population stood at 595 adults on the flood plains of the Rhine and Waal, and 128 cygnets, and had been fairly stable and increases on the Ouse Washes in eastern for some 20 years. It breeds quite freely in England). Sites holding large numbers and captivity in North America and Europe. A sites where there is a gradual increase in booklet ‘A Guideline for Propagation of numbers should be secured as reserves. Captive Trumpeter Swans' has recently been ‘Baiting’ wintering populations with grain published by the Trumpeter Swan Society has been shown to be successful in in­ (Box 32, Maple Plain, Minnesota 55359, creasing numbers at two existing reserves in USA), for those wishing to keep and breed Britain. To some extent, this has the disad­ this species. vantage of rendering large proportions of the population vulnerable to hazards such as pollution. Swan Goose Anser cygnoides It is one of the paradoxes of the The Swan Goose is a migratory species, Washington Convention that ‘Jankowski’s breeding in the steppe and forest-steppe Swan’ is listed, while Bewick’s Swan is not, zones of central Asia—in the USSR, from especially as some taxonomists argue that Sakhalin west to the Altai and Saissan the taxonomic distinction does not exist Depression; north to Transbiakala. Lake (Scott et al. 1972). Baikal and the Minusinkaya Depression; and southwards into west Mongolia and north­ Bewick’s Swan, Eastern race (Jankowski’s east China. It winters in eastern China from Swan) Cygnus columbianus jankowskii the Yangtze to Fukein and the Kwankug coast, occurring irregularly in Japan, WC Appendix 2 (as Cygnus bewickii although until 1950 it used to be a common jankowskii) winter visitor there, particularly to Little is known about the numerical status of Shinhama, Chiba Prefecture. It is now rare this race but it is likely that the population is in the two most northerly Japanese islands larger than that of the western one. It breeds (Yamashina 1974). It formerly occurred in between the Lena and Kolyma deltas on Korea but is no longer found there in winter northern Siberia and migrates to Japan, (G. Archibald, pers. com.). Korea and western China as far south as Despite the lack of a reliable population Kwangtung province for the winter.