Red Buzzards still pose mystery in South Africa’s Cape Peninsula By Ann Koeslag

 

The eastern slopes of Table Mountain, South Africa, were covered with pine trees until the widespread fires of summer 1999-2000. Though the Constantiaberg was hardly affected by the fires (while other areas were completely denuded of trees), there has been a determined deforestation effort in the area, taking the form of harvesting of the pine trees in the interests of alien clearing. An offshoot of the Black Sparrowhawk Project (about 30 prs of Black Sparrs use the plantations  for nesting in and around the mountain) has been the monitoring of other tree-nesting raptors. What we found was a mystery species of buzzard nesting in the plantations on the Constantiaberg and elsewhere in the Western Cape.

In 2002 a plain reddish buzzard was seen nesting with a very dark looking bird. Both birds superficially looked like Steppe Buzzards (Buteo vulpinus) but more uniform reddish-brown. They raised one chick which didn’t have the usual pale breast with streaks that is usually seen on young Forest Buzzards  (B. trizonatus) – the only buzzard that typically nests in the area. The following year two Red Buzzards raised two chicks in the same nest.  Both of these juveniles were very similar to the previous year’s youngster.  At that point the nest tree was felled because the trees were being harvested for timber. Subsequently, a Red Buzzard bred  to the north of the original nest in 2007 and 2008, fledging five chicks in all. Those juveniles were either red or brown chested.

 

Birders and photographers, Rob Martin and Jessie Walton reported that they have also had a number of very dark and red buzzards breeding in the plantations around Grabouw (60 km away) for a number of years.

This is both interesting and mysterious because, besides Jackal Buzzards (mainly cliff nesters), the Forest Buzzards, which are pale chested with brown blotches, should be the only buzzards breeding in this area. At first we surmized that the Red Buzzards were Steppe Buzzards who had over-wintered in the area, and had subsequently decided to breed here. That could still be the case, but the puzzling thing is that these Red Buzzards don’t appear to have much barring on their chests, bellies and flanks. Furthermore, the bird on the Constantiaberg is entirely red. To complicate things, in the last two seasons her mate has been a typical Forest Buzzard! And then to really confuse us, two buzzards, one red and the other dark brown, were found breeding on a cliff face of Table Mt above Kirstenbosch Botanical gardens in 2006 and 2007. Neither Steppe nor the Forest Buzzards are known to nest on cliffs!

So we have ourselves a mystery we are trying to solve. It was decided to trap some of these odd birds, but they have, so far, proved too wily to be trapped at the nest. We have managed to get some specimens from six chicks and hope that their DNA will give us some answers.

I have examined buzzard skins at the Cape Town Iziko Museum but other than three dark brown birds there were no totally red buzzards. David Allan kindly had a look at what was at Durban Museum, but unfortunately they didn’t have any specimens either.  Museums have not been preparing skins for some time, so if these birds are a recent phenomenon they are likely to be present in skeleton form only, rather than as skins.

We would be very interested to ascertain if anyone has observed these red buzzards breeding in other areas of Southern Africa. Photographic images of these birds have been sent to Dr Anita Gamauf who suggested that they may be “Long Legged Buzzards” (Buteo rufinus) though there are morphological differences, and the Western Cape is well beyond their reported range.  

– Ann Koeslag (Volunteer for the Black Sparrowhawk Project)

  Percy Fitzpatrick Institute

  University of Cape Town