RE: No honeyeater migration yet

[Peter Woodall <>]

Hi David and Alastair

Migration is complex, as David indicated, but there is no doubt that in
some parts of
the country, friarbirds are/were regular migrants, in the sense that they
were absent for
some time of the year and then present at other times and this was a
regular, annual pattern,
although the magnitude varied from year to year,

The late JS (Jack) Robertson was a bander and an accurate and regular
observer at his property
"Terete" at Wellington Point jutting out into Moreton Bay,
south of Brisbane.  I analysed and published
his detailed records for 1963-1976 (Sunbird 1983 17:1-14) and both Noisy
and Little Friarbirds were
absent or at very low numbers over summer (Nov-Jan) and then increased in
numbers to a peak in
April-May.  On several occasions in May he counted over 100 Noisy
Friarbirds per hour, flying north 
past his property, a maximum was 208/hr in July 1966 over a period of 2
hours.

I am not sure if the movements are still so obvious, and in another study
in the Brisbane Valley that
I'm currently writing up, Noisy Friarbirds have shown a significant
decline in the last third of a 24-year 
period and Little Friarbirds show a similar (but not statistically
significant) decline.

In many of these cases there seems to be a good deal of year-to-year
variation and therefore it is 
essential to have data covering long periods so that the underlying
pattern can be discerned.  I tried
(and failed) to come up with good reasons for the annual variation,
trying to do simple correlations
with factors like rainfall and honey production.  I think the real
reasons are much more complex, as
David indicated, and we need more detailed information on the flowering
of individual species of eucs.
in many localities to explain this variation - and that info is very
difficult to obtain.

Peter

At 09:44 AM 1/04/2005 +1000, you wrote:

> Alastair wrote
> "My understanding is that while
> you have mentioned Noisy Friarbirds on the move in the context of
> honeyeater migration, friarbirds are not migrants in the true sense of
> the word (i.e. moving from cooler to warmer), rather they move between
> areas of flowering eucalypts, which may take them in any
> direction." 
>
> First things first.  There are many, and varied,
> definitions of migration.  Most people picture migration as the
> classic Point A to Point B, back to Point A.  This may fit many
> northern hemisphere migrants but is not a terribly good fit for many
> Australian species.  A number of texts on migration (that I
> Unfortuneately don't have in front of me at the moment) deal with
> migration simply as a series of movements that may, or may not, be
> regular or take the animal back to it's starting point.  One author
> went to the extreme suggesting that migration is any movement that takes
> the animal outside it's immediate area of familiarity (there's better
> word!) - ie over the hill, across the river. 
>
> This was a concept I was dealing with when researching
> Cattle Egret migration.  We had birds that would migrate from their
> natal colony in northern NSW to Victoria (1000 km) each year, some birds
> wintering in the same paddock each year while others switched wintering
> areas.  Most of these would return to the natal colony to breed
> while others bred at other sites.  Then there were the birds (from
> the same colony) that would move 500 km, 100 km or even just 10 km away
> for the winter.  All of these birds were deemed to have
> migrated.  In short, migration can be a complicated concept.
>
> Back to friarbirds and honeyeaters.  Honeyeater
> migration is generally not well understood.  There are the strongly
> migratory species - Yellow-faced and White-naped, for example but even
> these species may have more resident components within populations. 
> I personally regard Noisy Friarbirds to be among the more migratory of
> the honeyeaters - up there with the Yellow-faced and White-naped. 
> Yes, they do move between flowering areas but, then again, so do the
> smaller migratory honeyeaters.  The very nature of the Australian
> bush dictates that they must.  Only a few areas (eg some heathlands)
> have what could be deemed to be a reliable nectar flow.  The
> temperate woodlands of south-eastern Australia may have Mugga Ironbark
> flowering one winter, White Box in another or nothing at all.  Where
> there is flowering you will often find large numbers of migrating
> honeyeaters.  No blossom (or more strictly n! o nectar) = no
> honeyeaters.  This is obviously an oversimplification but you get
> the general message.   
>
> This scenario is something I'm trying to come to grips with
> in regards Regent Honeyeater movements.  I personally think Regent
> Honeyeaters have a movement pattern that is largely programmed. 
> This however, can be, and often is, easily over-ridden by environmental
> factors. (such as a rich nectar flow).  In some years Regents move
> far greater distances than in others.  I don't think these movements
> are random (the species was previously thought to be "nomadic"
> - a state some authors encompass as just another form of
> migration).  I think they move through a series of resource-rich
> patches (by which process - eg a "collective memory" - I don't
> know) testing each and moving on if they fall short until they reach an
> area where resources are sufficient for their needs.  As I say, I
> think the process is complicated, often masked by environmental
> factors.  Mind you, here is a chance I'm complete! ly wrong and that
> I know absolutely nothing about Regent Honeyeater movements.
>
> Now, there's some food for thought. 
>
> Cheers 
>
> David Geering
> Regent Honeyeater Recovery Coordinator
> Department of Environment & Conservation
> P.O. Box 2111
> Dubbo  NSW  2830
> Ph: 02 6883 5335 or Freecall 1800 621 056
> Fax: 02 6884 9382
>
>
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