Re: Bird Migration

Subject: Re: Bird Migration
Date: Tue, 26 Aug 2003 14:15:29 +1000

The following from Tony Croker (I hope you don't mind my reproducing it)
Don't know if you've kept up-to-date with Cattle Egret movements across the Tasman. At the time they started coming here in the 70s I was a fairly keen young birder who looked, as we all did, confidently to the day when they would start to breed here. They never did. Then, oddly, they started to diminish in numbers, so that flocks of hundreds dropped to tens, tens to a handful and some "traditional" sites dropped out of view. Who knows why? Incidentally, I remember reading all those papers about the migration based on weather patterns that Max wrote for Notornis.

In addition, your comment about starting out to find land  - most years the NZ beach patrol scheme picks up one or two dead CEs. I recall a record at Milford Sound where a small flock pitched in exhausted. Some of them died at the site and the rest, presumably, headed further east. There's no suitable CE habitat at Milford. They've also been recorded landing on ships mid-Tasman. So it seems to be an unbelievably hazardous venture for CEs. So why do it? Some birds must be making the trip repeatedly, or otherwise they wouldn't coalesce at the same places.

Back to waders  - how do things like the handful of godwits that make it out to the Chathams each year get there, and why? I'm finding this pretty fascinating too! But above all, of course, there's still a hell of a lot we don't know about migration.



I haven't been keeping my finger on the egret pulse but was vaguely aware that numbers had declined in NZ.  Why?  Bloody good question!  

We know that weather systems had a lot to do with actual numbers that went across.  I wonder if a series of years without the right conditions set them back or whether too few birds made the return to Australia for the migration to become properly established.  Of the tagged egrets from Australia seen in NZ none were ever seen back here.  This is in direct contrast to birds that went to places like Tasmania.

I had a least three tagged birds (that I can recall) retrieved from the Tasman (one by a Belgium yachtsman) or from ships.

You're right, there's a hell of a lot we don't know.  Right now I'm struggling with where all the Regent Honeyeaters disappear to!



David Geering
Regent Honeyeater Recovery Coordinator
NSW National Parks & Wildlife Service
P.O. Box 2111
Dubbo  NSW  2830
Ph: 02 6883 5335 or Freecall 1800 621 056
Fax: 02 6884 9382

This message is intended for the addressee named and may contain
confidential information.

If you are not the intended recipient, please delete it and notify the sender. Views expressed in this message may be those of the individual sender, and are not necessarily the views of the NSW National Parks and Wildlife Service.
<Prev in Thread] Current Thread [Next in Thread>

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the birding-aus mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU