Taxonomy and biogeographic populations. The Slaty Egret (Egretta vinaceigula), also previously known as the Brown-throated or Red-throated Egret, belongs to the family Ardeidae (Order CICONIIFORMES) which includes herons, tiger-herons, night-herons, bitterns and egrets. The Slaty Egret first became known to science on the basis of two specimens obtained in the 1870s by Xxxxxx Xxxxx and housed in the collections of the British Museum (Natural History). Originally wrongly identified as juvenile Black Herons (Egrets) (E. ardesiaca), they were then shown to represent an unnamed species Melanophoyx vinaceigula (Xxxxxx 1895, Potchefstroom, Transvaal). In 1958 a third specimen was obtained, by R.H.N. Xxxxxxxx, in the Caprivi Strip. The work by Xxxxxx et al. (1971) showed on morphological and ecological grounds that the Slaty Egret was a separate species and not a colour phase of the Black Egret. Xxxxxx et al. believed that the Slaty Egret was found chiefly in the Chobe River system of northern Botswana although it is now known that the Okavango Delta holds a much larger population and that it occurs widely in Zambia. The Slaty Egret is monotypic, birds being similar morphologically throughout the range of the species. Distribution throughout the annual cycle Birds appear to breed following xxxxxxx of high rainfall. In Botswana and Namibia the breeding season is from March to July but colonies are not used every year. Birds move within the Delta according to the state of floods. They follow floodwater into newly inundated areas and also favour areas that are drying and where fish are concentrated. Within the Okavango system and the Chobe River floodplain distribution therefore, varies through the year. Some birds, particularly dispersing immatures, may wander beyond the core breeding and feeding areas, especially outside the breeding season (non-breeding between October and January). At such times they may appear in South Africa (particularly in the sub-tropical north-east, rarely in the arid west), in Mozambique in the Zambezi Delta and in other areas of Zimbabwe. Habitat requirements Slaty Egrets forage at the edges of wetlands or in shallow often vegetated water in pans, lagoons and rivers. They roost communally either in mixed species or single species roosts in xxxx-beds and in Water Figs on islands in lagoons. Breeding sites in Botswana include xxxx (Phragmites australis) beds, Date Palm (Phoenix reclinata) thickets on islands in swamps, thickets of Water Figs (Ficus verruculosus) on islands in la...
Taxonomy and biogeographic populations. Phylum: Chordata
Taxonomy and biogeographic populations. Phylum: Chordata Class: Aves Order: Anseriformes Family: Anatidae Tribe: Mergini Species: Clangula hyemalis (Linnaeus, 1758) Common names Danish: Havlit English: Long-tailed Duck (also previously known as Oldsquaw in North America) Estonian: Aul Faroese: Ógvella Finnish: Alli Gaelic: Xxxx-bhinn German: Eisente Greenlandic: Alleq Icelandic: Hávella Inuktitut: Aggiajuk Latvian: Kākaulis Lithuanian: Xxxxxx xxxxx Norwegian: Havelle Polish: Lodówka Russian: морянка Swedish: Alfågel The Long-tailed Duck is monotypic, and there are two biogeographic populations in the African- Eurasian region: i) Iceland & Greenland, ii) West Siberia/North Europe. This Action Plan covers both African-Eurasian populations. Two further populations in i) East Asia and ii) North America are not included in this Action Plan.
Taxonomy and biogeographic populations. The Bewick’s Swan (Cygnus columbianus bewickii) is the Palearctic sub-species of the Tundra Swan2. The Tundra Swan is most closely related to the two other northern migratory swans – the Whooper Swan (Cygnus cygnus) and Trumpeter Swan (Cygnus buccinator) (Xxxxxx 1999). The Bewick’s Swan breeds on Arctic tundra across northern Russia, from the west coast of Cheshskaya Bay (east of the Kanin Peninsula) to Kolyuchin Bay in the Chukchi Sea. Bewick’s Swans in eastern Asia were previously considered to be a separate subspecies, X. x. xxxxxxxxx, but it is now generally held that these birds are of the race bewickii (Xxxx et al. 1997). Three populations of C. c. bewickii have been identified based on their wintering grounds. A large population of 21,500 individuals breeds in northeast European Russia and xxxxxxx in NW Europe. A much smaller population, of approximately 1,000 individuals, breeds further east and xxxxxxx in the Caspian region. The third population occurs in East Asia, outside the area covered by the Africa- Eurasian Migratory Waterbird Agreement (AEWA). This action plan deals only with the population that xxxxxxx in NW Europe.
