Common Buzzards in Co. Cork

The Bird Atlas fieldwork is not yet complete, but, from the preliminary maps already available, it is clear that one big winner since the previous Atlas is Common Buzzard, which has increased in range and population size. For those not familiar with the status in Ireland, the species was driven to extinction some time in the 19th century, recolonising in the middle of the 20th, but, for some time, it was more or less confined to Northern Ireland as a breeding species, due, mainly, to the fact that use of strychnine was legal in the Republic.

Since this was made illegal, in 1991, the situation has improved, and, by the late 90s, the species could be found along much of the east coast (the population in Co. Wicklow, which is believed to have possibly originated from Welsh birds, was established in the late 70s, but, as far as I am aware, they were never common there through the 80s...anyone with more exact data, feel free to comment). This spread caught our attention down here in Co. Cork, but, at that time, we felt that the rate of spread would see breeding birds reach us by around 2020, maybe earlier.

Small numbers of Common Buzzards started to be seen in the county much sooner than that, in 2001, but these always seemed to just disappear come the spring, and proof of breeding eluded us, though it was suspected in 1-2 areas owing to the presence of small groups in winter. Finally, in 2004, two pairs were proven to breed, the first proven breeding in Co. Cork (though it is almost certain that the species bred here centuries ago). Numbers increased over the next few years, but we still felt that they were quite scarce, for the most part.

A national soaring survey was held this spring, in an effort to estimate densities, map the range spread and such. While there had been a few sightings of small groups in spring before, nothing concerted had been attempted before, so a group of us here decided to survey as many known areas (and some where the species was not yet known) as we could, in addition to the allotted 10km squares. What we found was that there were far more Common Buzzards than we had ever believed, though admittedly some soaring birds seen in spring will have been in their 2nd calendar year, and, as such, would not have bred this year. In particular, in some favoured squares, densities are starting to rise, and the species could perhaps best be described as localised, yet common in some areas...in parts of east, south and mid Cork, especially.

In tandem with this soaring survey, it was decided to attempt to trap and ring/tag as many Buzzard chicks as we could manage, so this meant a lot of walking through woodland in an effort to find nests. In many areas, having only seen soaring birds in March, there was little or no indication of where the nest would be, so this work was often quite time-consuming. Where birds had been present for a number of years, there was also the problem of deciding whether a given nest was the current one, or one used in a previous season. Despite the difficulties, and the fact that some nests were just inaccessible, we managed to tag over 20 chicks, with others that were too small to tag just being ringed. All birds tagged in Cork this year have orange tags on their left wing (to denote the year of tagging) and dark blue tags on their right wing (denoting the area): anyone seeing one of these birds should contact either Dr. Allan Mee at allanmee AT goldeneagle.ie or Tony Nagle at tnagle AT eircom.net (replace 'AT' with '@').

I decided, as a sideline, to attempt to document the variation, of lack of it, within the growing Common Buzzard population in the county. For a very variable species, I had gotten the impression that our local birds were pretty uniform on the whole, and, while I wouldn't say that I have anywhere near enough data yet in the form of pics to draw any meaningful conclusions, it would seem that this is so. Regrettably, the most interesting birds I saw this year in terms of plumage variation were mainly 2cy+ birds seen in flight, or, in one instance, a very dark juvenile was at a nest in north Cork, but it and its sibling were deemed old enough to possibly end up jumping were the nest approached, so they were never handled. Interestingly, one of the parents at this nest was also darker than average: I hope to get some flight shots obtained by another birder on site at some stage. The other interesting birds were a bird with a whitish tail base and rustier area towards the tip (almost mirroring a typical pattern seen on adult pale/intermediate Long-legged Buzzard, though with the rusty area less rufous, and with an obvious dark subterminal band as is usual on adult Common Buzzard), and a 2cy bird seen near Cork city which was quite pale below, though not as much so as the really pale birds that turn up in countries like the Netherlands, say, in winter.

So, without further ado, here are some images.

Two images of the same chick, at a north Cork site. This bird was very close to fledging, and its sibling flew away a short distance when the nest was approached, and could not be ringed or tagged.

A complete brood ringed, tagged and ready to be returned to the nest (east Cork).

This lone chick was already quite mature on a date when other nests still had downy chicks...there seems to be a fair bit of variation in this respect. (mid/north Cork)

The first chick ringed in 2011. (east Cork)