> In the last 20 years the Atlas is showing range increases for the Crested
> Pigeon in the Perth - Busselton area, Port MacDonnell area of SA,
Melbourne
> - Port Phillip area, the ACT area, and the entire length of the NSW South
> Coast south of Sydney.
>
> Rory Poulter
>
Around parts of South Australia I have observed not only an extension of
range of the Crested Pigeons but also a dramatic increase in numbers in the
last five years.
Previously one could see small flocks of 3-5 in many parts of the state. Now
flocks of 15-25 are relatively common in some areas. (This could be a result
of some good breeding years in the areas I visit frequently but it doesn't
explain the wider picture of the extension of their range.)
As an aside, this points out one of the difficulties as I see it with
interpreting the Atlas data because it has not addressed the issue of bird
numbers.
For example, I regularly see flocks of 50 - 200 Galahs flying over, coming
to rest or to feed on our home block. Over the last 15 years I have recorded
Cockatiel on only a handful of occasions, yet when this occurs, each species
receives the same recognition as the Galah as far as the Atlas is concerned.
One Cockatiel is equal to 200 Galahs. This does not give a true indication
of the status of both species in this locality.
Since beginning to use a bird database some 4 years ago I have developed the
habit of always recording the numbers of each species seen, not just a list
of species. The resulting data can be quite interesting and revealing, as in
the case of the Crested Pigeon.
Perhaps what is needed is an Australia wide project like the Atlas which
records abundance as well as distribution. The downside of this would be the
size of the Record Sheets; they would need a space bigger than the existing
bubble to record the number seen thus extending the sheets to 3 or perhaps 4
pages. (This would not be a problem if all records were submitted
electronically, but that would preclude many active Atlassers)
Happy birding,
Trevor Hampel
Murray Bridge
South Aust
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