Can someone who knows explain exactly what the definition of a 'feral' bird is? I'm aware that it is not quite the same as an 'escape' living successfully in the wild, but what is the differrence. For instance, I'm thinking (Redcar watchers will know what I mean) of the Barnacle Goose and the couple of Greylags that are living with the local Canada Goose flock. And what of Greylags in general - which are wild and which are 'feral'?
Confused...
Quote from: steveduke on January 30, 2009, 08:37:56 PM
Can someone who knows explain exactly what the definition of a 'feral' bird is? I'm aware that it is not quite the same as an 'escape' living successfully in the wild, but what is the differrence. For instance, I'm thinking (Redcar watchers will know what I mean) of the Barnacle Goose and the couple of Greylags that are living with the local Canada Goose flock. And what of Greylags in general - which are wild and which are 'feral'?
Confused...
Actually that's how I'd describe one - a bird that has been in captivity and having escaped has managed to survive and even to establish breeding population in the wild.
See here for a more detailed description/definition - http://www.stanford.edu/group/stanfordbirds/text/essays/Feral_Birds.html (http://www.stanford.edu/group/stanfordbirds/text/essays/Feral_Birds.html)
Greylag Geese in Cleveland are a mixture of feral and wild birds. eg. a local farmer introduced Greylag Geese to Scaling Dam about 20 years ago (using winged birds he had rescued) and they have built up to around 400 birds through breeding but the population is supplemented by immigrant wild birds from the Icelandic population and Scotland. The well known neck collared bird NDF is an example of this.
The Barnacle Goose situation is more complex. A feral population in Yorkshire (once up to 200 birds but I don't know the current population) appears to have originated from free flying birds at Flamingo Park Zoo in the 1980's. Bizarrely, they sometimes 'migrate' to Hornsea Mere in the winter. Some Yorkshire birders will only tick Caerlaverock migrating birds (the big numbers in late September or early October). Odd birds in Cleveland with Canada Geese are probably mostly feral (possibly from the Yorkshire population). However, the compexity of the situation is well illustrated by the two Barnacles on Coatham Marsh on 24 to 31 October 86. They seemed far too tame to be wild birds and in a very enclosed urban area for a week but they had both been ringed in Spitzbergen so were undoubtedly wild.
Canada Gese are obviously feral apart from the few USA birds which appear in Scotland (eg. 3 races this winter at Caerlaverock). Mini Canada Geese with Atlantic race Canadas in England are probably all interbred mixed up birds of no particular race (eg. the Locke Park/ Coatham area bird in January 03 which was wrongly published as Parvipes in the TBC report).
Pink-footed Geese are also a problem. Up to 3 at Scaling Dam are feral (put there originally by the local farmer) but I tend to tick any larger groups seen in winter. Odd birds around Saltholme also appear to be feral (again, if you see a large enough flock you are on safe grounds).
Snow Geese in Cleveland have all been feral in my view so it should not be on the county list. There used to be a feral population in Yorkshire but I was told recently that this has died out. However, it is only a matter of time before one of the birds migrating between Scotland & Norfolk gets seen here and they are generally regarded as tickable (eg. by Birding World). Ironically, if Ross's Goose gets added to the UK list in category A, the Saltholme bird on 5th October 07 is a much better candidate than any of the Cleveland Snow Geese. Pity I missed it!
Incidentally, introduced species on the UK list on this basis (such as Mandarin, Egyptian Goose and Canada Goose) are tickable despite being feral but feral examples of wild species (eg. an escaped Red-crested Pochard) are not tickable. This can seem a bit complicated to new birders. Dave Britton