Black-shouldered Kites

["Philip Veerman" <>]

Hi Benj,

All you say is quite correct. The GBS Report does say this (some bits put in bold here):

 

Black-shouldered Kite Elanus axillaris

This is a conspicuous small raptor with obvious hunting method of hovering over grassland and habit of perching on the pinnacle of dead tree tops or power lines. It is interesting that the results for this species confirm the independently known very irregular pattern of abundance. Even though overall it is a fairly common species of raptor, its occurrence is inconsistent. Because of its habitat preferences, records are likely to be influenced by locations of observers bordering large open areas. However, that cannot be the full story as there is always a selection of sites fitting that description. The Nankeen Kestrel, with similar habitat preferences, shows no similar population variability and both these species readily fly over suburban areas close to favoured habitats. This species is more of a specialist hunter than other local raptors, with a strong preference for rodents. Rodent numbers are also very variable, not just locally but in surrounding parts of NSW and this bird probably responds to this. As with other raptors, its seasonal pattern shows an increase during the breeding season. This raptor is unusual however in that it is a winter breeder. Numbers are at a peak in July then drop smoothly down to a minimum by February, with an immediate rise from March to June leading to the July peak. Numbers by year were high in the first two years followed by a drop in 1983. Numbers then built up inconsistently but slowly for the next nine years with a peak in 1993, then a drop off and increase again. One breeding record, a nest July to August in Year 12 at Site 236.
Graphs on page: 92, Rank: 73, Breeding Rank: 80, A = 0.01796, F = 12.22%, W = 25.7, R = 1.456%, G = 1.23.

I would add that none of the falcons build their own nest, the kestrel nests in hollows, on buildings, and in other birds discarded nests like chough's nest and stick nests (the later is what most of the falcons do). The two species do compete for prey to some small extent as in they don't have completely separate diet, more just different proportions. I believe the kestrel eats more birds than the BsK. I don't think that "when one is common the other leaves", they can partition prey preferences but when there is a real mouse plague, there is more than enough food for all the avian predators available.

 

As for "professional birders on the list" you are right. Whether or not someone is a professional anything, primarily relates to whether they earn money from it and this is not related to having a University degree.

 

Philip