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nialltkeogh
December 13th, 2009, 04:07 PM
Hi all,

On the 22nd July this year I mist-netted an Accipiter sp. in a cashew plantation adjacent to some secondary forest edge/farmland at Labundo Bundo village, Buton, SE Sulawesi. Mist-netting was being carried out as part of ongoing monitoring of the avifauna of the Lambusango forest reserve & surrounding buffer zones by Operation Wallacea.

My gut feeling is that it was a Small Sparrowhawk (Accipiter nanus), as opposed to Spot-tailed Goshawk (Accipiter trinotatus) which was the original ID made by the local bird guide at the time. The only other hawk species recorded on the island which it may be is Vinous-breasted Sparrowhawk (Accipiter rhodogaster).

The attached pics were taken by Phil Wheeler. I had better pics on my own camera but managed to wipe my memory card before I got home! I am trying to see if I can retrieve these as they show the underparts, thighs and legs which would be important for ID. Rather foolishly I decided to take pics as opposed to writing a detailed description at the time!!!

Some of my own (limited) notes on the bird:
- The bird is thought to have been a "sub-adult" due to the brownish, faded & worn unmoulted tail compared to the mostly fresh adult-like plumage on the rest of the bird. The colour on the cere and loral skin wasn't particularly strong indicating signs of immaturity. The underwing was also barred which may or may not have implications on ageing?
- The eye is distinctly yellow which is unknown for Spot-tailed Goshawk (dark eye) in any text or pics I have found.
- The cere & loral skin looks like they are coming through as yellow as opposed to the more orange colour expected of Spot-tailed Goshawk.
- The tail showed three faded pale spots alright which were used to ID it as Spot-tailed Goshawk at the time but these spots seem to be part of a pale/dark barring pattern which fits more in line with Small Sparrowhawk. I’ve found a few pics of Small Sparrowhawk on the internet which show adults having very faded spots on the tail.
- The rest of the tail was NOT black as seen in Spot-tailed Goshawk (of all ages).
- I believe that the colouration of the upperparts and crown are too pale for Vinous-breasted Sparrowhawk.

I hope there is enough info here to come up with a definite species ID. Small Sparrowhawk has been recorded on the island of Buton, but not in the Lambusango forest reserve as far as I'm aware and certainly not in the last ten years. A low altitude record of Small Sparrowhawk such as this would also be significant as it is meant to be a montane species according to Coates & Bishop (1997), with the lowest altitude recorded by them being at 550m. The site where this bird was caught is near sea level.

All the best,
Niall

pete
December 14th, 2009, 10:35 PM
Hi Niall

The bird is clearly not Spot-tailed Goshawk as you say. Habitat and altitude would strongly point to Vinous-breasted, and the bird does not look compact and petite like a Small Sparrowhawk, so I would guess it is most likely Vinous-breasted. Attached is a Small Sparrowhawk from Lore Lindu NP for comparison.

Cheers

Pete