I saw a Crested Goshawk (Accipiter trivirgatus) building a nest today.
Disclosure: I saw this nest building activity from some distance with only handheld photography and a long lens (150-600mm x 1.5 DX format), with no flash. I kept my distance and only watched for about 18 minutes (4 visits to the nest). The bird was aware of my presence and appeared generally comfortable with my presence and continued building.
I only saw one bird, a female at the nest bringing nesting material (above). In the female the breast streaks and belly bands are more ‘broken’ (better defined in males). The face in males is more grey, here more brown-grey. The nest was located 12-13 meters up a tall tree with an open crown (below).
The nest looked like it was being reused (refurbished). Most of the nesting material was carried in the beak (below) and could be very long sticks; they were collected 100-200 meters away from the nest. Once she spent 5-6 minutes rearranging sticks in the nest.
Of interest is the observation shown in the image below. After the second visit to the nest with sticks, the bird left carrying an item (below). I followed and managed to see that it was a large, dead chick; this surprised me. I did not see the bird eat the chick as it left and I could not follow it.
I asked myself what kind of behaviour was I watching? Some possibilities:
- Was this a failed nesting event, the chick had died and was being removed?
- Was this female Crested Goshawk taking over the nest of another Crested Goshawk and removing their young? I‘d expect some competition from the original parents.
- Could she have lost her mate and was terminating her breeding and staring all over again?
- Could this be an old nest of hers, long unused. And some other bird (heron) was using it for nesting. She was now claiming it back and removing the chicks (to be eaten or disposed away from the nest). I think this is the most likely explanation. Crested Goshawk chicks tend to be white and this chick is brown.
Appreciate other thoughts.
Amar-Singh HSS (Dato’ Dr)
Ipoh, Perak, Malaysia
Location: Ipoh, Perak, Malaysia
Habitat: Secondary growth at city fringe
Date: 24th January 2019
Equipment: Nikon D500 SLR with Tamron SP 150-600mm f/5-6.3 Di VC USD, handheld