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Sent: Friday, 26 May 2006 11:15 AM
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Subject: CSE seminar Fri 2/6 -
Breaking the evolutionary rules ...Eclectus parrots
CSIRO Sustainable Ecosystems seminar next week.....
Friday 2 June 2006
Breaking the evolutionary rules
Reversed plumage colouration and an unusual mating
system in Eclectus parrots
Rob Heinsohn
CRES, ANU
Time: 3.30 pm
Venue: Caughley
Seminar Room, Gungahlin Homestead, Crace (directions below)
Abstract below,
flyer attached
Enquiries: m("csiro.au","anne.towill");">, ph 6242 1608, or ph reception 6242 1600
Abstract
Brilliant plumage is typical of male birds, reflecting differential selection
for male traits when females are the limiting sex. Brighter females are a rare
phenomenon and are thought to evolve exclusively in response to sex role
reversal. However the striking reversed plumage dichromatism of Eclectus
parrots (green males, red and blue females) does not fit this pattern as they
are not sex role reversed. We quantified their plumage colours using
spectroradiometry and showed that very different selection pressures are acting
on males and females. Male plumage reflects a compromise between the conflicting
requirements for camouflage from predators while foraging and conspicuousness
to conspecifics during display. Females stay at the nest hollow for the whole
breeding season and are liberated from the need for camouflage. Their colours
are a permanently conspicuous signal of hollow ownership. Our molecular and
behavioural analysis of the Eclectus parrot mating system, using eight years of
data from our study population on Cape York Peninsula, revealed an unusual polygynandrous
system. High variance in reproductive success caused by this mating system
appears to have led to strong sexual selection in both sexes of this species.
Location details: The entrance to Gungahlin Homestead
is from Bellenden Street
(off Barton Highway,
approx 500m north of Gungahlin Drive overpass).
The visitor car park is to the right of entrance near front of Homestead
(Reception). Please report to reception for a visitors pass.
Enquiries: m("csiro.au","anne.towill");">, ph
6242 1608 (Mon pm, Tues-Thurs) or phone Gungahlin reception - ph
6242 1600
If you wish to be removed from this mailing list email
m("csiro.au","anne.towill");">
Anne Towill
Marketing and Communication Group
CSIRO Sustainable Ecosystems
'Gungahlin Homestead'
GPO Box
284
Canberra ACT 2601
ph: 02 6242 1608 (Mon PM, Wed, Thu)
fax: 02 6242 1555
e-mail: m("csiro.au","anne.towill");">
CSIRO Sustainable Ecosystems website: www.cse.csiro.au
