One of the most difficult identification tasks for a lot of birders is splitting Sparrowhawk and Goshawk. I have been very fortunate over many years to have regularly seen both and this is certainly true where I now live in Wales. We have a few pairs of Goshawks in this region as well as Sparrowhawks.
If you do not see Goshawks regularly then the perceived ID problems will be on your mind time and time again. First of all forget the regularly used warning of “Watch out for big female Sparrowhawks”. It is true that this can be an ID pitfall but once you realize that a male Goshawk and a female Sparrowhawk are so different then the problem will go away.
Goshawks are powerful birds and every bit of their courageous reputation is true. A female should pose no problems as they are roughly the size of a Common Buzzard but there the comparison disappears. I reckon that my first impression of a female Goshawk is that at glance it can resemble a Hen Harrier. It is slimmer, longer tailed and more stream-lined than a Buzzard. This is particularly true of its flight. The slow steady wing beats are just nothing like the fluttery fast wing movements of both sexes of Sparrowhawks.
It gets a bit more difficult with male Goshawks. They can look a bit small but the deep chesty appearance is diagnostic as is the tail shape. Goshawks tend to have a more rounded tail. If you get a good view the white under tail coverts are also very striking. Sometimes you can get the impression that the white extends up the sides of the tail and even over the rump. The latter is an illusion probably caused by the long under tail coverts extending over the tail area in flight.
Sparrowhawks generally show much blunter wingtips whereas Goshawk wings are sharper at the ends and the head is much more protruding.
What is certain is the the jizz of both species is so different. The smaller Sparrowhawk is slight in stature and fluttery in flight. The Goshawk is larger and much more powerful looking. To be confident you need to see a lot of both species. This may not seem possible but I am convinced that there are more Goshawks out there then we may be led to believe. You just have to practice.
All of these features are well illustrated in the Crossley ID Guide and where else could you have such an assembly of photographs illustrating the points I have raised. It is not a question of using the Crossley Guide as a replacement for any other guide but more a case of using it in conjunction with the rest of your library. As further support for the Crossley Guide method think of this – If looking for a criminal would you rather have a painting or a photograph of the suspect? Think about it. Richard Crossley himself has told me that in most bird photographs you have an unfocused background but in his book the background is both in focus and a relevant habitat. For me this new volume will be essential as an additional aid in identifying difficult species.