As the last geese withdraw from Ireland on their long journey, they tend to gather at preferred sites. Local to me here in County Down, this is in Inner Dundrum Bay, Killough Harbour and at the Strangford Lough Narrows.
One thing to look out for at this stage is the high percentage of juveniles. These young birds are generally still fairly obvious, with the white edging to their back feather plumage, and this differentiation will still be observable whilst we are in Iceland next month. Some, however (presumably resulting from the earliest broods last summer), are now less so, and only one or two small flecks of white remain on those feathers, usually located nearest to the bird's rump.
A local example of this build-up has been at Millquarter Bay in the Strangford Lough Narrows. Two days ago, I counted 61 juveniles out of a flock of 134 birds (46%), and yesterday, at the same location, there were 27 juveniles in a flock of 76 birds (36%). It is apparent that having a family in tow can hold back the migration progress, and research, resulting from collating observations of individual birds which have been ringed, has shown that this delay can result in such adults being unable to take advantage of the narrow breeding window in High Arctic Canada, often leading to only year-about success.
No comments:
Post a Comment