Raptor identification
Birds of prey present a notoriously troublesome challenge when it comes to identification. This is partly because they are often seen fleetingly, or distantly, or because they are just seen in flight, or because many species look pretty similar. Fear not, though, we have only a relatively low diversity of raptors in this country, so confident ID can usually be achieved with most birds of prey encountered. Here are some key factors to look for.
Broad grouping: broad-winged or falcon
The falcons are traditionally regarded as being in the same taxonomic order as the other diurnal birds of prey
(ie hawks, harriers, kites, eagles etc), but modern genetic studies have suggested that in fact they are probably only distantly related, but just have similar looking hooked bills and talons. Whatever classification you follow, our falcons tend to be small and pointed winged, whereas the rest of the ‘hawks’ tend to be larger, broader and blunter winged.
Overall size
Although judging absolute size of a bird is one of the trickiest of all things, with luck, there will be another bird (eg a mobbing crow) or some other feature of the landscape to compare any given bird you encounter. Smaller raptors include Merlin, Kestrel, Hobby and Sparrowhawk. Medium-large birds include harriers, buzzards and Red Kite, while we have just two whoppers: White-tailed and Golden Eagle.
Wing shape
Check out the amount of pointedness, the aspect ratio (ie how long a wing is compared with how broad it is), how ‘fingered’ the primary flight feathers (at the wing tip) are, and how many separate ‘primary fingers’ you can count.
Tail length and shape
As it says ‘on the tin’: how long is the tail, how wide is it, and is the tail rounded, square or forked at the tip?
Body shape
Does the bird look chunky or slim, does the head look small or large?
Colour and pattern
Many raptors (particularly the Buzzard) are highly variable in their colours and pattern. Others are pretty fixed. Some are diagnostic, such the orange-brown colour of Kestrel upperparts or the longitudinal streaking of juvenile Goshawk.
Flight style
One good way of identifying flying raptors is by the jizz of their flight style. Sparrowhawks have a flap-flap-glide direct flight; harriers and Buzzards glide with wings held in a shallow V; Honey Buzzards hold their wings flat in a glide, and so on.