Saturday, 30 April 2016

Late Season Birds in Ireland...

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.

Friday, 29 April 2016

Icelandic conditions in Ireland

The sudden cold snap has no doubt left our arriving summer migrants wondering if they've perhaps made a sea crossing too far; for our Brent, well a bit of ice and snow is familiar territory. But, aside from the length of the days one could be forgiven for thinking it was February or March!

As expected numbers of Brent at many of our sites have significantly dropped away in the last few weeks and the recent high pressure and slack winds were the catalyst for that. These last few weeks into early May mean it's the end of the 2015/16 chapter for Brent Geese in Ireland.

Shortly the Brent team will, for just about the tenth successive year, be in the staging grounds in Western Iceland: reading rings, downloading GPS data from the Dublin-tagged birds (which will give us information on the timing, route and duration of the migration from Dublin to Iceland), studying behaviour and rates of energy gain and catching and marking more birds.

Thanks to all for contributing your valuable sightings this year to Graham and for helping with cannon-netting catches. And thanks of course to Graham for his unwavering hard work at reading lots of rings himself, communicating with the large volunteer network and so many hours under desk lamp processing records. Our dataset is near-unique, has enormous benefits for understanding so many aspects of the ecology of this flyway population and each and every contribution is valuable.

Watch this space for further updates from the Iceland end of things as this last spring chapter unfolds.

Monday, 18 April 2016

The journey to Iceland and beyond: insights from past telemetry

Now with birds already in Iceland, numbers building there and falling here (and some passage and short-term stopover en route north through Ireland and W Scotland) weather will play a key role in determining the speed of the migration to SW Iceland.

Information on how this journey is conducted is limited to just a few satellite-tracked birds now about a decade ago. Birds from Co. Kerry (n=2) migrated via the west coast (Inner Galway Bay) and birds tracked from Wexford headed up the east coast, staging at Dundalk, Carlingford and Strangford for up to around 1 week.

Our most detailed series of tracks show a bird leaving Wexford on 16th April in SE winds, stopping at Dundalk (< 1d), Carlingford (2d) and Strangford (5d) - a total of ca. 7 days - and then making the flight at nightfall on 23rd April. Within 24 hours the bird was at Alftanes in SW Iceland but it had made landfall by 18:00 (about 20 hours after departure) taking a route E of Rathlin Island and to the west of the Outer Hebrides. That bird was in fact seen at Castle Espie and at Alftanes at either end of the journey!

That individual staged in W Iceland until 30th May and as this season progresses we'll describe the stages of the journey to give a flavor of the timings and routes that the birds of 2016 will be experiencing.