Ornithological Observations
An electronic journal published by BirdLife South Africa and
Ornithological Observations accepts papers containing faunistic information about birds. This includes descriptions of distri breeding, foraging, food, movement, measurements, habitat and plumage. It will also consider for publication a v
relevant ornithological material: reports of projects and conferences, annotated checklists for a site or region, specialist other interesting or relevant material.
CARRION ATTRACTION:
Recommended citation format:
Ryan PG, Shaw JM, Van der Merwe R, Van der Merwe E 2012.
Vol 3: 102-106
Ornithological Observations
An electronic journal published by BirdLife South Africa and the Animal Demography Unit at the University of Cape Town
Ornithological Observations accepts papers containing faunistic information about birds. This includes descriptions of distri breeding, foraging, food, movement, measurements, habitat and plumage. It will also consider for publication a v
relevant ornithological material: reports of projects and conferences, annotated checklists for a site or region, specialist other interesting or relevant material.
Editor: Arnold van der Westhuizen
CARRION ATTRACTION: GOSHAWKS AND OTHER BIRDS
Peter G Ryan, Jessica M Shaw, Rona vd Merwe, Emily vd Merwe
Ryan PG, Shaw JM, Van der Merwe R, Van der Merwe E 2012. Carrion attraction: Goshawks and other birds captured on camera trap
URL: http://oo.adu.org.za/content.php?id=49 Published online: 22 August 2012
Ornithological Observations
the Animal Demography Unit at the University of Cape Town
Ornithological Observations accepts papers containing faunistic information about birds. This includes descriptions of distribution, behaviour, breeding, foraging, food, movement, measurements, habitat and plumage. It will also consider for publication a variety of other interesting or relevant ornithological material: reports of projects and conferences, annotated checklists for a site or region, specialist bibliographies, and any
Editor: Arnold van der Westhuizen
IRDS CAPTURED ON CAMERA TRAPS
Peter G Ryan, Jessica M Shaw, Rona vd Merwe, Emily vd Merwe
Carrion attraction: Goshawks and other birds captured on camera traps. Ornithological Observations
/oo.adu.org.za/content.php?id=49 22 August 2012
the Animal Demography Unit at the University of Cape Town
bution, behaviour, ariety of other interesting or bibliographies, and any
RAPS
Ornithological Observations,
Ornithological Observations, Vol 3: 102
CARRION ATTRACTION: GOSHAWKS AND OTHER BIRDS CAPTURED ON CAMERA T
Peter G Ryan1*, Jessica M Shaw1, Rona and Emily van der Merwe
1Percy FitzPatrick Institute, University of Cape Town, Rondebosch 7701, South Africa
2Tierhoek, PO Box 171, Calvinia 8190, South Africa
*Corresponding author:
Southern Pale Chanting Goshawks
diet that includes carrion as well as a wide variety of mammals, birds, reptiles, frogs, insects and other invertebrates. Malan and Crowe (1996) summarise observations of them feeding on carrion, list Spotted Eagle Owl Bubo africanus
capensis, Steenbok Raphicerus campestris
megalotis and hares Lepus spp. We report how a pair of adult Southern Pale Chanting Goshawks fed on a dead Egyptian Goose Alopochen aegyptiaca in the Hantam Karoo
2012. The goose was one of 15 put out under power lines to see which scavengers removed bird carcasses from under the lines.
Such data are important when estimating how many birds are actually killed after colliding with power lines from the numbers detected by researchers who check the lines at regular intervals.
Camera traps (Bushnell Trophy Camera, model 119436
erected next to the geese carcasses to see what animals scavenged from the carcasses.
Southern Pale Chanting Goshawks visited at least two of the geese carcasses, and were the dominant scavenger at one carcass. This latter goose, deployed shortly before sunset on
within 200 m of a Southern Pale Chanting Goshawk nest, where a pair was sitting, probably incubating. Two adult goshawks, presumably from this nest, arrived at the carcass within 20 minutes of it being placed under the power line. They
, Vol 3: 102-106
GOSHAWKS AND OTHER CAPTURED ON CAMERA TRAPS
, Rona and Emily van der Merwe2 Percy FitzPatrick Institute, University of Cape Town, Rondebosch 7701,
South Africa
Tierhoek, PO Box 171, Calvinia 8190, South Africa
*Corresponding author: [email protected]
Pale Chanting Goshawks Melierax canorus have a catholic diet that includes carrion as well as a wide variety of mammals, birds, reptiles, frogs, insects and other invertebrates. Malan and Crowe (1996) summarise observations of them feeding on carrion, listing Bubo africanus, Spotted Thick-knee Burhinus Raphicerus campestris, Bat-eared Fox Otocyon . We report how a pair of adult Pale Chanting Goshawks fed on a dead Egyptian Goose in the Hantam Karoo near Calvinia in July 2012. The goose was one of 15 put out under power lines to see which scavengers removed bird carcasses from under the lines.
Such data are important when estimating how many birds are colliding with power lines from the numbers detected by researchers who check the lines at regular intervals.
Bushnell Trophy Camera, model 119436) were erected next to the geese carcasses to see what animals scavenged
Pale Chanting Goshawks visited at least two of the geese carcasses, and were the dominant scavenger at one carcass. This latter goose, deployed shortly before sunset on 3 July, was located Pale Chanting Goshawk nest, where a ing, probably incubating. Two adult goshawks, presumably from this nest, arrived at the carcass within 20 minutes of it being placed under the power line. They may have been
attracted to the site by arrived less th
carcass for 33 minutes, until it was
period, one bird stood by while the other fed from the carcass, standing on its back and plucking the feathers before eating
The second bi
18:15, 25 minutes after local sunset Later that night a Cape Fox
was apparently scared off by the camera triggering, leaving the carcass largely untouched ove
the carcass at 10
minutes until scared off by a domestic dog (which only sniffed the goose). Presumably
a further 193 minute 118 minutes) until 17
adult goshawk again returned to the carcass on 5 July, spending 173 minutes at the carcass in two bouts (12
16:51). Its feeding rate was slower during this period, probably because it had already removed most of the meat from the carcass.
What impressed us most was the persistence of this bird; assuming it was the same individual in each case, it spent more than 7 ho the carcass over two days. Other birds visited some of the other goose carcasses.
A pair of Verreaux’s Eagles
one carcass in two short bouts within 24 hours of it being put out (Fig 3). This carcass also attracted Cape
albus and a
scavenged at several other carcasses carcasses, and Pied Crows 4 carcasses days. R
despite their regular occurrence in the area.
attracted to the site by a pair of Cape Crows Corvus
ed less than 2 minutes earlier. The goshawks remained at the carcass for 33 minutes, until it was almost dark. Throughout this period, one bird stood by while the other fed from the carcass, standing on its back and plucking the feathers before eating
The second bird left at 18:13, and was followed by the feeding bird at , 25 minutes after local sunset.
Later that night a Cape Fox Vulpes chama visited the carcass, but was apparently scared off by the camera triggering, leaving the carcass largely untouched overnight. One adult goshaw
the carcass at 10:50 the following morning, feeding for another 30 minutes until scared off by a domestic dog (which only sniffed the goose). Presumably the same goshawk returned at 12
a further 193 minutes at the carcass in three bouts (lasting
118 minutes) until 17:31 (Fig 2). With no further nocturnal visitors, an adult goshawk again returned to the carcass on 5 July, spending 173 minutes at the carcass in two bouts (12:21 to 13:41, and 15
. Its feeding rate was slower during this period, probably because it had already removed most of the meat from the carcass.
What impressed us most was the persistence of this bird; assuming it was the same individual in each case, it spent more than 7 ho the carcass over two days. Other birds visited some of the other goose carcasses.
A pair of Verreaux’s Eagles Aquila verreauxii virtually demolished one carcass in two short bouts within 24 hours of it being put out
. This carcass also attracted Cape and Pied Crows
and a Southern Pale Chanting Goshawk. These crows also scavenged at several other carcasses: Cape Crows visited 5 of 15 carcasses, and Pied Crows 4 carcasses, returning for up to three days. Rather surprisingly no White-necked Ravens
despite their regular occurrence in the area.
102
Corvus capensis that remained at the dark. Throughout this period, one bird stood by while the other fed from the carcass, standing on its back and plucking the feathers before eating (Fig 1).
lowed by the feeding bird at
visited the carcass, but was apparently scared off by the camera triggering, leaving the rnight. One adult goshawk returned to 50 the following morning, feeding for another 30 minutes until scared off by a domestic dog (which only sniffed the eturned at 12:58, spending s at the carcass in three bouts (lasting 73, 2 and . With no further nocturnal visitors, an adult goshawk again returned to the carcass on 5 July, spending 173 41, and 15:18 to . Its feeding rate was slower during this period, probably because it had already removed most of the meat from the carcass.
What impressed us most was the persistence of this bird; assuming it was the same individual in each case, it spent more than 7 hours at the carcass over two days. Other birds visited some of the other
virtually demolished one carcass in two short bouts within 24 hours of it being put out and Pied Crows Corvus Pale Chanting Goshawk. These crows also : Cape Crows visited 5 of 15 returning for up to three necked Ravens were seen,
Fig 1. An image of the Southern Southern Pale Chanting Goshawks feeding on the carcass at dusk on 3 July 2012 (taken with infraPale Chanting Goshawks feeding on the carcass at dusk on 3 July 2012 (taken with infra-red flash).red flash).
Ornithological Observations, Vol 3: 102
Fig 2. The
, Vol 3: 102-106
The Southern Pale Chanting Goshawk feeding on the carcass during the dPale Chanting Goshawk feeding on the carcass during the day on 4 July 2012.
104
Fig 3. A pair of Verreaux’s Eagles feeding on aeaux’s Eagles feeding on a goose carcass.
Ornithological Observations, Vol 3:1 102
Acknowledgements
We thank Francois and Marian van der Merwe for their excellent hospitality, and for supporting research on power line collision mortality. Rob Crawford and Bruce Dyer from the Department of Environment Affairs kindly loaned the camera traps for the experiment, and Mick D’Alton and the landowners of the Nuwejaars Wetland Special Management Area
References
Malan G, Crowe TM 1996. The diet and conservation of mono gamous and polyandrous Pale Chanting Goshawks in th Karoo, South Africa. South African Journal of
1-10.
, Vol 3:1 102-106
We thank Francois and Marian van der Merwe for their excellent hospitality, and for supporting research on power line collision Rob Crawford and Bruce Dyer from the Department of Environment Affairs kindly loaned the camera traps for the Mick D’Alton and the landowners of the Nuwejaars Wetland Special Management Area provided geese carcasses.
. The diet and conservation of mono- gamous and polyandrous Pale Chanting Goshawks in the Little
ican Journal of Wildlife Research 26:
106
