January 13th – Snow Buntings…are Amazing!!!

I fell in love, so to speak, with Snow Buntings on my first sojourn into the Arctic – Devon Island in 2004. The camp at Cape Vera was at latitude 76 degrees – that’s a long way north. Birds up there have to be hardy! Cape Vera is an excellent place for Snow Buntings to breed as there are large boulder fields at the base of the 300 m cliffs. Buntings build their nests in cracks and holes in and under rocks, sometimes up to 25 cm deep. The males arrive as early as April when temperatures can drop into the -30’s and the females arrive about 6 weeks later. In no time (there’s VERY little leeway for error in the Arctic) the nests are built (by the female) and clutches of up to 8 eggs are laid. The males will feed the females on the nest while she is incubating since, in these climes, leaving the eggs unattended to feed might jeopardize them (at Cape Vera a cold wind seemed always to be blowing: either off the waters of the open ocean or off the glacier just behind). The young hatch asynchronously; that is, unlike most small landbirds where the eggs hatch all at once, Snow Bunting eggs may hatch as much as 36 hours apart, youngest to oldest. So some young may be considerably younger (and thus smaller) than their siblings. This is an interesting strategy by the parents. When food is plentiful all will get fed and fledge. In bad years only the oldest will survive. The birds never know what the conditions will be ahead of time but start off hoping for the best.
The parents feed the young for a few days after hatching but soon stop as they have to take care of their own energy needs – they have to moult all of their feathers quickly before Winter starts. The young gather into large flocks to feed. Joined later by adult birds, these flocks will head south – pushed out by the Arctic storms.
Two years ago Dr. Oliver Love and I came across an article (it was in the airplane magazine on our flight South from Baffin Island) stating that Snow Bunting populations had declined by 64% in the past 40 years due to global warming. We were pretty sceptical about this – that a decline would be due to global warming – and so started out to study them. We had started to do this in the Arctic but discovered very little is known about them when they come South to spend the Winter. (“South” here means the southern parts of the Prairie Provinces, Ontario, Quebec, and the Eastern Seaboard into the Northern United States.)
So we’ve started to study them down here. One thing we’re trying to do is band them with the hope that some will be recovered and we can find out where they go (most of the birds wintering in Southern Ontario are thought to breed in Greenland – due to a few banding recoveries). As well, we are taking feather samples from the birds we catch (just 1 small wing covert feather). From this we are hoping to roughly identify where the birds might be breeding using stable isotopes – a subject too complicated to get into in this article.
Using the expertise and equipment from Ruthven we have had great success. Ruthven banders, Nancy Furber, Christine Madliger (these ladies just got their banding sub-permits!) and I were able to track down a large flock on the Sandusk Road. We put out “bait” (cut corn) and, when the birds started to go to it, put out ground traps to catch them. These birds travel in flocks, sometimes up to 500+ birds although 40-50 is more usual. The flocks are “serendipitous”; that is, they travel around looking for patches of food that they can exploit and, when it’s used up, move on. So a flock you see today could be miles away tomorrow. Unless…..there’s a lot of cut corn lying on the snow. Then they will stay. And there’s an adage that’s very useful in this context:” feeding birds attract other birds”. And this certainly has been the case here. When we first found the flock it numbered ~175 birds. Two days later (with baiting in early morning and later afternoon) we counted over 2,000. The birds have stayed at the site or, I guess it would be more accurate to say that some of the birds have stayed while some have moved on only to be replaced by others. For the past several days there have been 200-300 birds around but we’ve caught only ~10 that we banded before…and at the time of writing (January 12th) we have banded 598!

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