Budgie numbers more common in February-April

I am wondering if I see a pattern now over these past years in Aus where
huge flocks of budgies are more common in February – April rather than
typical Aussie spring months of lets say September – November?

I did see a flock of about 1000 at Bowra in September of 2008 but perhaps
the pattern is for more fall winter abundance?

Thanks for the input and as always I appreciate this site!

Don Kimball