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Female Rufous-chested Sparrowhawk which had been feeding the chicks in the nest
As background;
- the location is a mix of bamboo and dense shrubs with patches of Eucalypt trees and located about 800m-1km from the perimeter of the Volcanoes National Park, Kinigi (about 20km from Musanze) and at altitude of c2560m.
- earlier the year Dave had regularly seen a pair of Rufous-chested Sparrowhawks (A. rufiventris) hunting around the lodge area including once seeing an adult take a waxbill.
Today;
- nest located at the edge of a stand of Eucalypt trees about 20-30m high; typical small stick nest - one composite of Dave's photos attached shows a juvenile bird on the nest
- Dave has regularly witnessed the female adult feed the 2 chicks in the nest; the latter fledging about 2 weeks ago - no male bird accipiter was seen anywhere near this location up to this stage.
- my photos of the juvenile, a very obliging model eventually, was just after it had caught and eaten a Chubb's Cisticola and it was very obviously rather stuffed.
Rufous-chested Sparrowhawk - juvenile
Now the 'strangeness' - we both managed to get photos of the female and a juvenile; the undersides are very similar with blotchy, almost streaky rufous marks on the chest going down toward the belly with a stronger rufous wash/patch on the flanks. In the event of this being A. rufiventris, the underside plumage of the adult female is in direct contrast to all literature (Sinclair & Ryan, Zimmerman et al, Kemp, Britton and Stevenson & Fanshawe) which mention that the female is darker underside than the adult male.
Rufous-chested Sparrowhawk - juvenile
The underside plumage of the juvenile as seen and photographed is not illustrated, mentioned or even alluded to in any of the above literature. The only 'agreement' is on the feint /pale eye-stripe and (as mentioned in 2-3 cases) the rufous ear area giving the bird a capped look.
Responses this far;
Callan Cohen (Birding Africa): The juvenile plumage of Rufous-chested Sparr is quite variable, but your bird is certainly consistent with what we see in South Africa (the same race, rufiventris) -- normally the chest is streaked rufous (can be quite dark brownish), but then some of the feathers show some some barring which normally becomes more apparent lower down (you can see some of these barred feathers on this bird). They can end up looking quite mottled. Juvenile birds around Cape Town quite often show those white feathers on the back so it's curious as to why that doesn't seem to be mentioned in the literature.
Etienne Marais (Indicator Birding): Little Sparrowhawk is known to breed while still showing juvenile plumage, in the case of the pair I was monitoring in Pretoria, South Africa the female died of unknown causes and was replaced within ten days by a “young” female still showing immature plumage. I’ve heard other reports of this from Hugh Chittenden in Zululand.
Update (22 Oct)
Michel Louette (Head of Department African Zoology, Royal Museum for Central Africa, Tervuren, Belgium) I have checked the specimens in our collection. These birds are A. rufiventris. The parent bird must be a “second calendar year”. A. rufiventris is very close to A. nisus, based on the COI molecular study (see Van Houdt, J., Sonet, G., Breman, F. and Louette, M. DNA barcoding of European Accipiter and their African relatives. Abstract 2009 EOU Zurich).
Bill Clark: I was shown a nest of a pair near Stellenbosch in Cape Province years ago in which the female was not fully adult. The pair looked just like yours.
Dave Richards managed to get photos of another individual yesterday (21 Oct) that was continuously calling throughout the morning until c.2:30pm. Below is the photo - this appears to be a 5th individual as it's clearly not one of the 1st three we photographed and is also not the male bird we saw fly past us the other that had the dark rufous underside - a textbook version of A. rufiventris male.
(photo by Dave Richards)
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