Saturday, 30 August 2014

Coming soon to a golf course near you?

This week, the American Birding Association Checklist Committee voted unanimously to accept the Egyptian Goose (Alopochen aegyptiacus) as an established exotic in south-eastern Florida and added it to the official ABA Checklist.  Birds have been present in Florida for 20 years and there have been numerous records of breeding; without doubt the population is now self-sustaining. Although the species is found elsewhere in North America (e.g. Arkansas, California and Texas) those populations are not yet regarded as being established and presumably therefore are not ‘tickable’ but it seems likely to be just a matter of time.

Egyptian Geese were introduced to Britain as early as the 17th century and have bred in the wild for over 200 years.  Until comparatively recently they were more or less confined to Norfolk but there has been a gradual increase in numbers and fieldwork for Bird Atlas 2007-11 has shown a significant recent range expansion including scattered winter records from Shetland, west Wales, Cornwall and even Ireland.

In Holland, too, there has been considerable expansion and the population there has been estimated at about 11,000 pairs, or 50,000 individuals post-breeding.  There are also breeding populations in France and Germany.     

This week’s Noticiário Ornitológico included a record of 13 Egyptian Geese at the Alqueva reservoir near Évora in eastern Portugal, close to the border with Spain.  This continues the trend that we have seen this year for increasing reports of this exotic species in Portugal.  In June and July birds were seen in the Algarve at Lagoa dos Salgados.  These latest birds were seen on 23rd August south of Roncão and they represent the largest flock seen so far.  Not so long ago reports of Egyptian Geese were referred to as escapes from captivity but this description has now been dropped and the reality surely is that these birds are arriving from the established and expanding feral populations in Northern Europe.  

Two of the most obvious field marks of the Egyptian Goose are the chestnut eye patches surrounding its yellow eyes, and a brown chest patch.  There is also a brown stripe that forms a collar around the nape of the neck.  The bill is pink, with a black tip and a dark base. The male has green secondaries, but a large portion of the adult wing is white. The white usually remains hidden when the bird is at rest, however, the white wing feathers are easily seen when the bird is in flight. The under tail coverts are cinnamon colored:  the upper tail is black.  The sexes look alike, but the female is slightly smaller.  Juvenile birds are similar to adults but lack the distinct facial markings.

Of course, the Egyptian Goose isn’t really a goose at all; it is believed to be most closely related to the shelducks (genus Tadorna) and their relatives, and is placed with them in the subfamily Tadorninae.

Egyptian Geese are native to sub-Saharan Africa where they are widespread and numerous; we have seen them on most of our visits to Africa.  In many areas they are regarded as agricultural pests because they sometimes feed on or trample crops and in South Africa they occur in large numbers on golf courses where they cause physical and financial damage to the courses and are a nuisance to golfers and golf course managers.  In Holland they are reported to be aggressive towards breeding waders.  We do wonder therefore whether we should be looking beyond the novelty of having these birds arriving and instead considering the potential for them to quickly become an unwelcome nuisance.

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