The Collared Sparrowhawk A Review and Comparison
with the Brown Goshawk.
Czechura, Debus, Mooney
Vol. 12, No. 2, June 1987 ,pages 35 - 62
This paper should be read by all who want to more confidently
identify the two birds.
Here are some extracts...
... " While the difference in tail shape is real and
important, our field experience and check of museum spesimens suggest that some
qualification is required. "
... " since a tail which is square when folded is often
rounded when fanned "
... " Feather disarray, moult or abrasion can affect tail
... " We suggest that other characters (e.g. silhouette,
flight pattern) be used to supplement field identification, and that observers
be aware of exceptions to the general rule. "
An interesting note is
... " The main distinguisher field character, tail shape, has
been common knowledge only since 1970 (Slater 1970) "
This would mean that observations before this date would
have to be suspect ?
My table is an attempt to summarise some other identifying
features, in a simple form for the non specialist observer.
Regards, Bob Forsyth, Mount Isa, NW Qld.