Gus Ariss drew my attention last week to a Tweet by Mark Clarke who had seen 37 Red Kites near Shipston and who wondered what was going on? I wondered too. The next day I was followed on Twitter by Keith Jennings whose account had numerous references to a winter roost in north Gloucestershire. I had forgotten about winter roosts and the pieces now fell in to place. Had we an established winter roost in the south of the county? Or had the Gloucestershire roost recently moved north? Gus and I determined to take a look at the end of the week.
We met at Honington at midday. I periodically check that area, with Firecrest and Hawfinch in mind and having drawn a blank on my first post-invasion visit had finally found one of the latter on 11/01. Third time was lucky and I saw 14 on 23/01 when it became apparent they were feeding in Yews in the gardens which run along the western flank of the road to the church. The advantage to the number of birds present is that they are very active and vocal, presenting an excellent opportunity to commit the range of calls to memory and get used to seeing them at all sorts of ranges. That Friday afternoon we also discovered they were, along with c.60 Goldfinches, feeding in three incredibly tall London Plane trees at the churchyard boundary. Gus had quickly noticed the birds often flew west, in the direction of a strip of gallery woodland with an evergreen understorey full of Yew. We walked out of the village to check whether birds were commuting, Gus set up his scope and said quietly, ‘have a look in here’. A flock of Hawfinch were spread across the crowns of three Ash trees. Gus counted 19, I counted 20 and Gus resumed his place at the scope where he got a final count of 22, pretty good for Warwickshire, even this year.
After a half-hour or so of trundling around in the general area for the kites we were driving along a narrow back-lane and discovered four siting in trees right next to the road. There were ten in the immediate area and we knew we had found what we were looking for.
Red Kites at pre-roost gathering.
Having checked that we were in a place consistent with the sightings (the Print brothers having seen a large flock too) we eventually began to see birds which had obviously come some distance, arriving at height on a purposeful track. the number we could see in the trees was not increasing though. Then I picked up two birds which overflew the area we were concentrating on and continued west. We followed them to a copse, Gus put his scope on the section of the wood the birds disappeared in to and found 11 birds in the canopy. We started our count with those and added every bird we saw fly in.
By dusk our tally was at exactly 60 when what Gus rather neatly describes as a ‘dread’ occurred. A crow flew in to the south side of the copse and a few kites moved, apparently in response. After a few minutes, what we took to be the entire roost got up and began milling around low over the tree tops. A precise count was impossible but we were fairly confident that 70-80 individuals were involved. This constitutes the highest tally for the West Midlands region, by a factor of 10 or more. It is, more significantly, a splendid afternoons birding, surrounded as you are by the glorious landscape of the Cotswolds.
Photo by Gus Ariss.
Gus and I have been wondering, why this particular copse? There are after all, woods everywhere in the Cotswolds. We completely forgot to ponder, why roost communally? The answer to the latter question may hint at the answer to the first. Red Kites are social raptors, there are few of them but their number also includes another group of scavengers, the vultures. It has been hypothesised that kites in a roost can see which individuals have fed well, as indicated by a bulging crop, allowing less fortunate birds to follow the corpulent ones back to the location of a carcass the next morning. This theory was not supported by radio tracking work in Spain however which did support another proposed explanation for winter roosts, that birds follow each other from them to forage together. The greater the number of birds searching, the greater the chance of success in finding food. Given the likelihood that a food source will provide amply for several birds or more there is no disadvantage to such cooperative behaviour. So perhaps the physical characteristics of the roost wood are not the key determining factor in its selection. Perhaps, that is simply the proximity of the wood to an expanse of optimal foraging ground.
Finally, in answer to speculation that this phenomenon may herald a boom in the breeding population of Red Kites in Warwickshire, it appears probably not. The reason the species was reintroduced is that it has a really low dispersal rate naturally. I recently posted a photo of a first calendar-year bird taken nearby. What I didn’t know was that the first calendar year is about the only time a Red Kite wanders, after which it returns to the natal area to breed. Winter roosts are thus largely, though not exclusively, comprised of first calendar-year birds. Of the three in the photo included here, two belong to that age class. Keith Jennings has confirmed also that a significant number of birds from the Bourton roost appear to have gone.
I took this last photo at Long Compton some time ago, at a more amenable time of day.