In the Top End size range for male Brown Goshawk is 33-42 cm while for Collared Sparrowhawk it’s 30-40 cm (both genders). These measurements are from specimens held at the MAGNT.
Regards Denise Lawungkurr Goodfellow 1/7 Songlark Street, Bakewell, NT 0832 043 8650 835
On 12/1/13 3:46 PM, “Philip Veerman”
> Many of these bird species mentioned are entirely unknown to me and I’m not > going to try to find all of them in books but I will at least guess that for > many of them they are hard to identify because they are closely related, as > in have not diverged much, in which case there is no mystery about it. Also > mostly they are still almost the same in morphology and size (which the C. > Sparrowhawk & B. Goshawk certainly are not). There will of course be > variants in things like bill length among otherwise similar hummingbirds. > Also I would guess that for many of them it is the young, female and > non-breeding plumages that are similar. With often the breeding males (the > ones with the signalling functions) are often very distinct. So these are > mostly different situations to what I was asking. Besides, my question was > not about birds that are difficult to identify (that is not very > interesting) but about why these two species show the same plumage pattern. > As in I am not at all asking about our human perception, although some may > see that there could be an element of circular reasoning in that. > > Philip > > —–Original Message—–From: David Adams [mailto:dpadams@gmail.com] Sent: > Saturday, 12 January 2013 3:31 PM > To: COG line; Birding-Aus Subject: [canberrabirds] Re: [Birding-Aus] > [canberrabirds] Why are the C. Sparrowhawk & B. Goshawk so similar? > > > >> One minor point (I am also a Northern Hemispherian): Which birds are so >> difficult to identify in Europe and North America? Apart from maybe some >> Empidonax in North America and maybe some Phylloscopus, Acrocephalus and >> Hippolais in Eurasia/Africa I can’t think of many species that are that > hard >> to ID there. “Hard” birds are certainly not the norm there. > > Fair comment. I guess confusing is in the eye of the beholder 😉 Empidonax > are hard, for sure…I’d list some of the other tyrants as tough, depending > on how far afield you go. Apart from hawks, terns, gulls, pelagic species, > and shorebirds, I’d also say that in the New World there are hard pairs of > hummingbirds, alcids, flycatchers, ducks (e.g. Scaup), some of the New World > blackbirds, and New World warblers. And vireos…and plenty of young/female > tanagers. And sparrows…and finches. It’s fair to say that corvids are > probably harder here. (Unless you accept that they should all be lumped into > C. indistinctus, as proposed last year…) Even some of the loons Old World > warblers are tough in Europe. > =============================== > > To unsubscribe from this mailing list, > send the message: > unsubscribe > (in the body of the message, with no Subject line) > to: birding-aus-request@vicnet.net.au > > http://birding-aus.org > ===============================
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