Corellas

["Tobias Hayashi" <>]

Hi,
I am almost certain that there are three young Corellas which are hybrid 
Little x Long-billed Corellas (see
http://www.flickr.com/photos/callocephalon/2096744204/;

http://www.flickr.com/photos/callocephalon/2095966165/ )

Parents are:
http://www.flickr.com/photos/callocephalon/2096741186/; 
http://www.flickr.com/photos/callocephalon/2094180843/;
http://www.flickr.com/photos/callocephalon/2096740934/;

Reasons for concluding they're hybrids include:
-three young stayed in tree for a couple of days, did not fly much
-preened each other (http://www.flickr.com/photos/callocephalon/2096742724/)
-visited each now and then by two adult birds (one Little, one Long-billed), 
which fed them (http://www.flickr.com/photos/callocephalon/2095964399/), the 
Little more so than the Long-billed.
-young made begging calls to parents when they were around
-young rather shaky on wings, but otherwise normal

Any way of telling the sexes of the adult birds by behaviour/plumage?

Cheers
Tobias