John Cantelo
Well-known member
We're all used to Pied/White and Yellow Wagtails knocking around in groups but, family parties aside, it's not something that I've ever associated with Grey Wagtails. I imagine that this probably reflects their typically linear habitat along rivers. However, I was surprised last week to find 14 feeding together in a loose group on a circular bed with a sprinkler (filtration tanks?) on a small local sewage treatment works near Canterbury. Oddly enough, although there were Pied Wagtails present (c20) none of them shared a tank with the Grey Wagtails but almost all congregated on the second of the three tanks. I returned after the recent cold snap and found 24 Grey Wagtails (all but 1 or 2 on the same tank as last time). Numbers of Pied Wagtails had risen to c50 but these were again concentrated on the first two tanks (with no more than one occasionally joining the Greys).
How common are groups of this size? I can't find any records of a larger flock in Kent and several county avifaunas I have to hand suggest groups in double figures are unusual and one doesn't even mention winter counts (although counts on migration are regular). However, the Hampshire county avifauna mentions counts of 50, 60, and 27 all at Eastleigh Sewage Farm (elsewhere the highest was 14 also at a sewage farm). However, two larger (81 & 180+) winter roosts (as distinct from feeding birds) were found in Lower Test Marshes in the same county. So are we missing Grey Wagtails regularly forming small groups and feeding together in winter? If so old fashioned waterworks seem a good place to look (local 'improved' plants don't seem so attractive). Do they always form discrete flocks? In the current context high water levels and/or freezing conditions seem to help as other observers in the area report birds are absent from their usual haunts (also suggesting that any movements are very local). Other similar plants along the river don't seem to hold any concentration of Grey wags.
How common are groups of this size? I can't find any records of a larger flock in Kent and several county avifaunas I have to hand suggest groups in double figures are unusual and one doesn't even mention winter counts (although counts on migration are regular). However, the Hampshire county avifauna mentions counts of 50, 60, and 27 all at Eastleigh Sewage Farm (elsewhere the highest was 14 also at a sewage farm). However, two larger (81 & 180+) winter roosts (as distinct from feeding birds) were found in Lower Test Marshes in the same county. So are we missing Grey Wagtails regularly forming small groups and feeding together in winter? If so old fashioned waterworks seem a good place to look (local 'improved' plants don't seem so attractive). Do they always form discrete flocks? In the current context high water levels and/or freezing conditions seem to help as other observers in the area report birds are absent from their usual haunts (also suggesting that any movements are very local). Other similar plants along the river don't seem to hold any concentration of Grey wags.
