[hilbert42]

Very interesting. Come to think of it I can remember a time when ibises were never about (this was a time of sparrows before miners took over the city). Anyway, one year ibises suddenly appeared as if out of nowhere. (When I first saw them I thought they were some exotic bird that had escaped captivity.)

We may have destroyed their natural habitat but I reckon they're more than just hanging on—they seem to have adapted to our city environment extremely well.

Thanks, you've answered a question I posed above before reading your post when I said they're the dirtiest scruffiest birds I've seen and wondered how clean they'd be in a natural environment.

[donavanm]

Interesting indeed! Im definitely not authoritative, but my partner did some biology research and field work in this general area. My slightly vaguer recollection is that yes for Sydney there was a big mass migration year when the marshes and murray darling were particularly stuffed up.