Australian brushturkey: Difference between revisions

They build large nests on the ground made of leaves, other compostable material, and earth, {{convert|1|to|1.5|m|ft}} high and up to {{convert|4|m|ft|abbr=on}} across. Mound-building is done by a dominant male, and visited by a succession of local females, for mating and egg-laying. The male works tirelessly, collecting material from all around, and also diligently repelling rival males, which are keen to usurp his position. The effort involved eventually wears him down, and he will ultimately be defeated by a new king. The eggs are very large (90 × 45&nbsp;mm), and the young are fully fledged on hatching. They can fly within hours, as soon as the feathers are dry. The eggs are hatched by the heat of the composting mound, the temperature of which is regulated by adding or removing material to maintain the temperature in the {{convert|33|–|35|C|F}} incubation temperature range.<ref>{{cite web|publisher=NSW Department of Planning, Industry and Environment, New South Wales Government |url= http://www.environment.nsw.gov.au/plantsanimals/AustralianBrushTurkey.htm |title=Australian Brushturkey}}</ref> The Australian brushturkey checks the temperature by sticking its beak into the mound. Like some [[reptiles]], incubation temperature affects the sex ratio of chicks, but the mechanism is different between reptiles and these birds, with reptiles exhibiting temperature-dependent sex determination, and megapodes exhibiting temperature-dependent embryo mortality. The sex ratio in brushturkeys is equal at incubation temperatures of 34&nbsp;°C, but results in more males when cooler and more females when warmer ([[statistical significance|p]]=0.035). Whether the parents use this to manipulate the sex of their offspring by, for instance, selecting the nesting site accordingly, is unclear. Warmer incubation also results in heavier, fitter chicks (p<0.0001), but how this is linked to sex is also unknown.<ref>{{cite journal|last=Göth|first=Ann|author2=Booth, David T|title=Temperature-dependent sex ratio in a bird|journal=Biology Letters|date=22 March 2005|volume=1|issue=1|pages=31–33|doi=10.1098/rsbl.2004.0247|pmid=17148121|pmc=1629050}}</ref>