Over the last few weeks, walkers in Hemsted Forest near the Rogley Wood entrance will have been surprised to see so many people with telescopes looking up into what appeared to be just pine trees. It has been the first major bird “twitch” in the area for a long time. Winter bird watching in the forest can be quite a dull affair but the coniferous trees do attract quite a few winter visitors such as Crossbills, Bramblings, Siskins and Lesser Redpolls. Over the years the Rogley Wood area has had a number of sizeable winter flocks of Crossbills that have come from Northern Europe. There is strong evidence that Hemsted Forest also has its own breeding flock, albeit only a small one. As Crossbills feed their young on pine seeds ground by the parent bird, they are able to breed much earlier than other birds and can start as early as November. There are four species of Crossbills in Europe and it is always worth looking through a flock for the other species, although it can be difficult to separate them from one another. One keen eyed-observer spotted, amongst a flock of Common Crossbill, a Two-barred Crossbill which derives its name from the two relatively broad wing-bars. Male and female crossbills have very different colours, the female being a well camouflaged green colour whilst the male has a bright red plumage which stands out strongly.

This Two-barred Crossbill was a lovely bright male and when word got around it immediately attracted a great number of birders from across Kent. Up until this year there have only been 182 records of this species nationally since 1950, averaging just under 3 records a year. 2013 has seen an unprecedented influx and birds have been recorded from The Orkneys down to Hemsted involving some 30 birds. This number might increase as more records come to light. This appears to be only the fourth record in Kent, the previous three being back in 1990/1 with two in Bedgebury Forest and one in Round Green, Goudhurst. The actual breeding range is the very north of Scandinavia to Eastern Siberia and it is mainly a resident bird in its breeding range, rarely travelling far. They obviously mix with their more common cousins who do wander more frequently and hence make the occasional crossing to the UK in search of pine cones, particularly in poor cropping years. There are not many opportunities for birders to see this species in Kent or the South East and it is not surprising that so many people came to view it and the excitement grew when an even keener-eyed bird watcher discovered a small flock of Parrot Crossbills amongst the flock. The Parrot Crossbill is slightly larger than the Common Crossbill but distinguished from it by the size of its bill which is getting on to be twice the depth of the Common. Otherwise its plumage is identical to that of the Common. It is because of this similarity that it often goes unnoticed. Excellent close up views are needed to separate the two species when the larger beak is obvious. Their call notes are similar but an expert ear can distinguish them, otherwise the use of a sonogram is a must. The Parrot Crossbill breeds in North East Europe and has bred in Northern Scotland. With its large bill it specialises in eating seeds from pine cones whereas the Common and Two-barred, who both have smaller bills, specialise in cones from Norway Spruce. However this cannot be relied on as a diagnostic feature as the smaller species will feed on pine cones when the cones release their seeds in spring. The Parrot is far less rare than the Two-barred as it often travels in years when there is a poor pine cone crop. Some irruptions do occur in the UK and over a hundred have been recorded such as in 1982 and 1990. Very surprisingly there seems to be only one record for Kent when one was caught in a bird trap in 1990 in Sandwich Bay.

I spent some time up in the forest watching them and on one occasion was lucky enough to see all three species in one tree. The Parrot Crossbill seem to have an individual feeding technique, using their beaks to grab pine cones on the end of the branch and walk back along the branch to a more sturdy point where they can use their feet to hold the cone before extracting the seed. This was frustrating at times as it made them more difficult to see. The Common tend to extract seed with the cone in situ. I suspect they are choosing the cones where the scales are more open and the seed easier to extract.

I mentioned earlier in the article that there were four species of Crossbill in Europe, the fourth being the Scottish Crossbill which is endemic to the pine forests in Northern Scotland. It is the only endemic bird species in the UK and much is made of this fact. However as its morphology is exactly between that of the Common and Parrot and with its plumage being also similar, it is impossible to identify with certainty in the field. The size of its beak being mid-way between the other two species seems to make it ideal for extracting seeds of the Scots Pine. Although it is restricted to Northern Scotland both the other species are also recorded there and some ornithologists believe the Scottish is a hybrid of the other two and not a separate species, however some DNA work supports the separate species argument.

Eleven out of the fourteen remaining Cuckoos are now in The Congo with two on their way there. There is concern for one Cuckoo from Sussex for whom no data has been received for two weeks and it may have perished.

Charles Trollope cetetal@btinternet.com