Hey Sandy! Ever seen the swifts roosting? Or suspected you might be in a place where that happens? Some of us witnessed this many years ago near Brisbane – a lone bird flying repeatedly past a particular point at dusk ended up landing and roosting in a cluster of foliage near the top of the tree. Apparently this is normal behaviour for this species, but rarely seen. Cheers, Chris. On 06/12/2014 07:02 PM, Sandy Gilmore wrote: > Hi everone, > > A very timely question since I frequently get Yellow-tailed Black Cockatoos flying over and infrequently get Glossy Cockatoos flying over. > > While enjoying the sunset a few days back I had both species fly over a few minutes apart and it was abundantly obvious that Glossy Cockatoos flap their wings at twice or more the rate of Yellow-tailed Black Cockatoos. > > This is in the situation where I presume both were returning to their night time roosts and were flying high over a mixture of forest and cleared paddocks. > > Aerodynamics experts would be able to explain this inter-specific difference based substantially on their relative body weights, and wing areas and wing spans. > > See http://jeb.biologists.org/content/150/1/171.full.pdf > > On another matter I have increased my White-throated Needletail sightings over summer by an order of magnitude, plus observing other interesting birds, by taking time to observe the sunset as often as possible. > > Cheers, > > Sandy > > > > Sandy Gilmore > Arid Zone Ecologist > > Bush Heritage Australia > “Morinda” 240 Mafeking Road, Goonengerry NSW 2482. > > Conservation Support Centre > Level 5, 395 Collins Street, Melbourne Vic 3000 > www.bushheritage.org.au
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Swifts at sunset.Comments are closed. |
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