At 12:26 AM 5/6/98 +1000, Chris Barnes wrote:
>Had a chance to visit Little Desert NP briefly & had a spectacular 45
>minutes when 1,505 honeyeaters flew north on a broad front early one
>morning. At least 75% were White-fronteds, about 20% Tawny-crowneds & the
>rest New Hollands. The blossum was patchy where I was but saw 12 sp of
>honeyeaters in a relatively small area. Are these numbers of White-fronted
>usual? Would be interested to hear if others have had similar experences.
>
Hi Chris,
Such erruptions of White-fronted Honeyeaters (WFHEs) are sometimes recorded
in the Australian mallee. The most impressive erruption that I have
personally witnessed was in the early 1980s, in the mallee surrounding the
Eyre Bird Observatory, Nuytsland Nature Reserve, in Western Australia.
Several thousand WFHEs arrived at Eyre literally overnight in early 1981.
When numbers reached their peak, there was an estimated 5,000 birds within
a 1 km radius of the observatory. Prior to this occasion, WFHEs had only
been recorded once in the area in very small numbers since the
observatory's operation in 1975.
This influx coincided with massive flowering of the mallee after unsually
heavy rains. Interestingly, WFHEs have been regularly recorded at Eyre
since this big erruption. However, such large numbers haven't been seen
there since 1985, even though smaller erruptions have occurred since then.
Purple-gaped Honeyeaters (PGHEs) were very common at Eyre before the WFHE
erruption. However, they pretty much disappeared from the immediate area
when the WFHEs arrived, and did not return until WFHE numbers dropped
considerably. It is very tempting to say that WFHEs, when in large numbers,
competitively excluded PGHEs from the area. However, this was never tested
experimentally.
Such events demonstrate the importance of permanent or long-term
observatories, especially in the semi-arid zone, so that incidents like
these can be recorded.
Cheers,
Stephen
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Dr Stephen Ambrose
Research Manager
Birds Australia (Royal Australasian Ornithologists Union)
Australian Bird Research Centre
415 Riversdale Road,
Hawthorn East,
VIC 3123.
Tel: +61 3 9882 2622
Fax: +61 3 9882 2677
Email:
1997 Australian Bird Research Directory is on Birds Australia's
home page: <http://www.vicnet.net.au/~birdsaus>.
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