Central Canberra Gang-gang Census 1 August
Background
A census of the central Gang-gang population was arranged for Sunday 1
August 2010, from 11am-12pm. The idea originate in an online
disagreement between two Canberra bird-watchers over the size of the
winter Gang-gang population in central Canberra, one participant
favouring a low figure of 50 birds, the other a high figure of 250.
The time of day was chosen from knowledge of Gang-gang and other
cockatoo behaviour; it was anticipated that at this time the
Gang-gangs would be feeding in groups and not flying around. This
would help to eliminate duplicate counting of birds.
Observers were recruited from the canberrabirds mailing list and
selected or were assigned areas to survey during the Census period.
Central Canberra was designated as the likely number of volunteers was
not anticipated to be large enough to cover a wider area. The
following areas were surveyed during the Census:
1. NW O’Connor, O’Connor Ridge
2. suburban Turner
3. suburban Ainslie
4. Mt Majura fringes
5. CSIRO Black Mountain area
6. ANU Campus
7. Australian National Botanic Gardens
8. Campbell
9. Commonwealth Park
10. Black Mountain Peninsula
11. Weston Park
12. Parliamentary Triangle
13. Telopea Park
14. Narrabundah eastern boundaries
15. suburban Forrest (north-eastern Red Hill)
16. suburban central Griffith
17. Narrabundah/Griffith suburb
18. southern Red Hill
19. northern Red Hill and Deakin
20. north-western Red Hill
Observers were asked to move around in their area for the hour, noting
groups of Gang-gangs, their location, and their composition
(male/female/immature male). Observers were also asked to note
Gang-gangs heard calling but not seen, and Gang-gangs flying (with
time and direction, to help eliminate duplicate reporting).
Results
The morning of 1 August 2010 saw a cold front crossing the ACT; before
the Census period and up until 11.45 there were cold gusty
north-westerly winds blowing, and in addition at 11.45 rain began to
fall. These were not ideal observing conditions.
All areas surveyed during the Census recorded nil returns except for
Commonwealth Park, where 9 birds were observed (4 males and 5
females), and Griffith (Flinders Way), where 3 birds were observed
flying over.
In addition 3 birds were observed flying over Forrest shortly after
the Census period (these may have been the same birds observed earlier
over Flinders Way).
Discussion
12 Gang-gangs observed in the entire central Canberra area is unlikely
to be a good reflection of actual numbers. In the poor weather
conditions it is likely that Gang-gangs were sheltering in dense
foliage (as were the Commonwealth Park birds) and so escaped
detection.
The Gang-gang is not a well-studied species and reference works such
as HANZAB do not provide overall measures of abundance. The winter
concentration of Gang-gangs in central Canberra (and over the wider
Canberra urban area) is well-known and is the only winter
concentration in or near a urban centre. If monitoring of this
population is undertaken long-term it is likely that useful data on
the population level locally can be gained. The 2010 Census provides a
baseline for further data. It is hoped that this Census can be
repeated annually.
Thanks to all observers.
--
John Leonard
Canberra
Australia
www.jleonard.net
I want to be with the 99,999 other things.
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