Common Crossbill
Widespread from the lowlands to the highlands, happy in non-native plantations but also found alongside Parrot and Scottish in native pine woods.
Scottish Crossbill
Used to be thought that this one was very much a bird of the ancient caledonian pine forest but has now been found to be more widespread than this with birds also inhabiting non-native plantations.
Parrot Crossbill
Apparently a relatively recent colonist discovered breeding in the ancient Caledonia pine forest. Subsequent research as shown that is often the commonest Crossbill species in such habitat.
The three species are separable(with experience!) on some types of call and on bill size and structure-at least in typical individuals although there is some overlap in this respect. The agitation 'toop' call is the one that apparently differs, that's the one you often hear from perched birds as they pick up on a threat such as a person walking through the forest. In Common this call is delivered rapidly while Scottish gives it at a slower pace and Parrot also has a rapid pace as well as sounding rather harsh. I've only heard the Parrot on CD but it almost had a Blackbird scurrying away alarm call quality to my ear.
I've had a few crossbills while out and about that have deeper bills than your average Common and had slow agitation calls and so were presumably Scottish Crossbills. I have not spent much time in the right places for Parrots and so look forward to connecting with this species in the future.
Presumed Scottish Crossbill
this bird showed a heavy looking bill with
slightly bulging lower mandible and tip of
lower mandible does not extend above
upper mandible
No comments:
Post a Comment