canberrabirds

Raptors vs. Galahs, or was it Galahs vs Raptors

To: "Canberrabirds" <>
Subject: Raptors vs. Galahs, or was it Galahs vs Raptors
From: "John Layton" <>
Date: Wed, 3 Jun 2009 10:43:52 +1000
Thrice during the past 14 days I've witnessed similar encounters between small groups of galahs and what I believe were Brown Goshawks from my Holt backyard. Although I'm aware of the difficulties of raptor ID, and in the cited incidents I was disadvantaged by lack of binos, my ornithological shoes keep walking back to Brown Goshawks despite the challenges of discerning between these and Collared Sparrowhawks. For starters I found the silhouette illustrations in HANZAB Vol.2 p134 went some way in colouring my decision. Also, I was treated to two re-runs of what were very similar screenings of the first sceneing ... I mean scene. Now let's fast forward to the action. So lights, camera ... no, gold darn it! Never had the latter to hand  'sides I would have needed a lens from here to the Pleistocene long for an acceptable outcome.
 
Thursday May 14 during sunny, clear conditions I saw what at first I took to be a flock of 5 galahs wheeling this way & that against an azure sky. Their erratic progress held my attention and I discerned that one of the birds was a smaller to medium-size raptor that didn't seem to be attacking, in fact I wondered if it wasn't being mobbed by the galahs After a few minutes the protagonists drew out of view. Saturday May 20, same conditions and performance i.e. galahs wheeling about willy-nilly issuing continual pealing, tinkling calls and at times the raptor seemed to draw away from the galahs only to be surrounded once again, or were the galahs moving away and the predator moving in among 'em again? Beats me. Incidentally, this time there were ~ 12 Galahs.
 
Monday May 23, again from the outdoor theatre i.e. Cinema de Hills Hoist, I was again attracted by the pealing, tinkling calls of some 25 Galahs and there in their midst was a raptor. But this time, as the Galahs and raptor drew apart momentarily, I noticed a second raptor and concentrated on memorising characteristics that could lead to identification. Going by the size of one raptor, I believe it was a Brown Goshawk rather than a Collared Sparrowhawk, my decision being greatly influenced by the aforementioned  HANZAB diagrams. Sometimes one raptor was in the midst of the Galahs, other times it appeared to be drawing away while its partner was in the melee. After ~ 3 minutes the birds disappeared from view.
 
I recently witnessed what I'm sure was cooperative hunting of Common Starlings between a pair of Brown Goshawks and sent the report to CBN as an Odd Ob, but am wondering if more than one pair will undertake cooperative hunting i.e. were there other goshawks loitering in the area that I didn't see.Other possibilities, perhaps young goshawks practicing their hunting skills, or adults honing already acquired skills and not intent on pressing home a red-in-bill-and-talon attack, Assuming goshawks do, in fact, indulge in such conduct.
 
Or maybe all were just cases of mobbing by Galahs. Dunno. Then, during another look through HANZAB, Vol 2, p138, I noted the following, METHODS OF ATTACK:  Most attacks rely on stealth and surprise  but may make numerous passes at airborne flocks" (Mooney 1987). Hmm, so maybe the hawks were launching serious attacks which emphasises the point that only a minority of predators' forays are successful.
 
John K.Layton.
 
 
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