Interesting. While reading your post it occurred to me that if Eastern Grey Kangaroos are interrupting seed set then there might be a relationship between Eastern Grey Kangaroo numbers and pigeon numbers.
My immediate interest in reducing feral pigeon use of some buildings and bridges is related to hazards to aircraft rather than reducing the total feral pigeon population (also desirable). The flock that used
to frequent the Fyshwick Sewage Ponds area has moved on, perhaps due to the changed management of the surrounding grasslands which are now regularly mown, this might have reduced seed availability.
I’ve examined crops of pigeons from many parts of Australia and recorded the foods taken. Pigeons mostly ingest their food with minimal processing, unlike parrots which can remove seed coats, pods etc. Some
favoured foods in our district include grain from stock feed, other exotic species such as Wireweed (Polygonum aviculare), various thistles (high fat content) and clovers (high protein). Seeds of native and exotic grasses are eaten, mainly those in
which the seeds fall without encumbering bristles or spikey bracts (e.g. Panicum, Echinochloa, Eleusine, Setaria). Drought will affect food availability directly through reduced seeding of plants and indirectly through overgrazing of food plants by
stock (might be replaced by grain fed to stock). Drought is likely to temporarily reduce pigeon breeding success and numbers, and perhaps distribution when more might forage for waste food in parks and town centres.
I hope that the increase in Crested Pigeon numbers in our district in the last 50 years has also introduced a bit of native competition for seed.
Alison R
Wow! As well as the listing of local breeding sites and roosts, there are many good general observations here about Canberra’s feral pigeons, with special thanks to Alison and Con among others.
Educating and persuading engineers to prevent pigeons breeding, when they design structures such as bridges, makes sense, of course. But for demographic reasons, the benefits will be local to the site (things
like reducing fouling from droppings). It will not change the number of Canberra pigeons. Demographics tell us that pigeon population size may be relatively insensitive to reduced breeding, and more sensitive to reduced adult survival. And there are many
alternative breeding sites available. Therefore if nests under solar panels kill the adult pair, as mentioned, installing more solar panels and not clearing away the nests at an early stage, would be better for pigeon control than good bridge design. That
interesting observation will sound cruel and barbaric to some. But here I am merely illustrating some interesting ecology, not advocating actions. I agree that killing animals by heat stroke may be less desirable than using approved pigeon control methods
such as the use of appropriate toxins in food. (Ideally we would do better still by widespread change in human attitudes and practices, and elimination of most of the food sources for feral pigeons by changing things like urban waste management, equestrian
recreation, and agriculture, but those would be impractical goals in the foreseeable future.)
I agree that many of Canberra’s concrete bridges and road overpasses provide safe roosting and nesting sites for feral pigeons and I would like to see these crevices removed at the design stage as retrofitting
exclusion devices is expensive and can block access for maintenance.
The flock that used to roost on the Campbell Park Offices may have been excluded by the netting on the west side of the building. Some of these birds probably moved to the Malcolm Fraser bridge (where Majura
Parkway crosses Fairbairn Avenue) as numbers there have increased in the last five years. They presumably have a ready food source (wheat and oats from hand-feeding) in the horse agistment paddocks in this area, as similar overpasses further north on the Parkway
which are surrounded by pine plantations and woodland have no pigeons.
Alison R
Geoffrey
In Civic I have from time to time found pigeons dead but with very full crops. I assume that these birds had been poisoned by building managers. Examination of the crop contents included items such as corn kernels which would not normally have been available
to feral pigeons in Civic.
Also in Civic, and formerly, there were also a high proportion of pigeons with deformed feet. I assumed that these were the result of chemical warfare by building owners to deter pigeons from roosting on their buildings.
The biggest regular flocks I used to see were those that used Campbell Park Offices as a roost. This flock still exists, but is now drastically reduced - I assume because of actions taken by building management. This flock may also have been impacted by
the drought and the impact on seed production in the peri-urban paddocks where it can be seen from time to time in the company of Galahs and Little Corellas.
Other than that, I have seen several local and smaller flocks rise, flourish and then fall. There used to be a flock of around 50 that hung around a certain residence in Turner near Sullivan's Creek. Either the owner changed his behaviour or the residence
changed hands. That flock is gone. that flock used to feed in Haig Park and in the playing fields and rough grasslands adjacent to Sullivan's Creek. Similarly there used to be a flock that hung around the O'Connor shops but which now seems to be gone.
From observation, I believe that if Pied Currawongs can reach the squabs then breeding success is not sufficient to replace the adult birds. Some of our bridges have currawong-proof niches and crevices and these have virtually perpetual populations of pigeons.
Such 'safe' sites have recently been added in tens of thousands to the ACT - solar panels. I have observed something like half a dozen attempts to breed in such places. I believe that the householders intervened in all cases but one to destroy the nesting
attempt. In that case the breeding attempt was destroyed when the adult birds perished under the panels during an exceptionally hot day.
I don't know whether the modern multi story buildings in the ACT include deliberate provisions for eliminating pigeon roosting and/or breeding sites.
The tide of gentrification whereby older houses with breeding crannies are being replaced by houses with none may be having an impact.
Increased competition with Common Myna scavengers may be having an impact.
Are schools more effective in recycling and reducing food waste behaviour by children in the playgrounds, thereby reducing a food source? Shopping Centre managers ditto? Have wheelie bins altered the availability of food scraps? Is the ever-declining proportion
of urban backyard space and nature strips having an impact?
Did water pricing and the drastic consequent impact on householders refusing to water their grassy spaces have an impact? (I believe that this may have reduced Canberra's worm population and hence Canberra's Common Blackbird population.)
In 2008 in Paris we observed various measures taken by the authorities aimed at reducing or eliminating pigeons. This included in targetting the numerous folk who took pleasure in feeding pigeons. This was in direct response to bird flu. I don't know whether
the ACT took similar measures to discourage/eliminate pigeons.
regards
Con
On 8/28/2019 10:14 AM, Geoffrey Dabb wrote:
I am engaged on a little project on the local feral pigeons. I’m interested in any reports of regular feeding aggregations or major roosting or nesting sites.
At the moment we are not seeing the large flocks we used to get around the open areas and on powerlines at JWNR. There are a few flocks to be seen on lawns in the parliamentary triangle.
The flock regularly seen flying over south Canberra is probably based at a local loft i.e. privately owned. There are probably similar flocks in North Canberra, which is the home of an active pigeon racing club.
Does anyone on this chatline keep pigeons?
