Hi everyone,
An off-list question from a member prods me to give a little more
information about Little Terns, not wishing to mislead for want of
information.
It gets even murkier, but I didn't want to addle the situation with more
complexity. You see, there are three populations of Little Tern in
Australia. Well, that's how it's described for want of better knowledge.
1.
The northern hemisphere population is a clearcut overseas breeder, as I
wrote in the earlier email.
2.
The east coast breeders all tend to arrive from September and breed
through the spring down the east coast. We don't know where they arrive
from.
3.
The northern Australian population, reaching from the western Gulf of
Carpentaria across the Top End as far as the Kimberley. This population
has been studied by Ray Chatto of NTNPWS, and from his aerial and some
ground surveys (as you can imagine, access to NT coastal areas can be
difficult) has shown them to be breeding in almost every month of the
year. We don't understand much at all about the breeding drivers in this
northern population, but it could be opportunism rather than
seasonality. I'm not aware of any recent findings to change that belief.
Cheers,
Jill
Jill Dening
Sunshine Coast, Queensland, Australia
26° 51' 41"S 152° 56' 00"E
On 15/03/2011 9:46 PM, Jill Dening wrote:
Hi Martin,
To explain to those who aren't familiar, the Gull-billed Tern occurs in
Australia in two subspecies. The one resident all around the country is
Sterna nilotica macrotarsa, while the Asian Sterna nilotica affinis
migrates in small numbers every summer from Asia. Mostly they are seen
in north-west Australia.
No, I have never seen an affinis here in SEQ. I have never laid eyes on
one, but would dearly love to. Now that's a bird I would travel to see.
I am very much aware of them (from Danny Rogers' excellent paper), but
have actually not seen many macrotarsa Gull-billed Terns in recent
times. I put this down to the recent abundant inland conditions. So an
affinis would stand out like the proverbial if one were present here. I
wonder if an affinis would follow macrotarsa Gullbills inland?
Paul Walbridge reported an affinis in Brisbane a good decade ago, but I
don't think there has been another reported since then - around here. I
guess it makes sense that if they are going to turn (!) up on the east
coast of Australia, Cairns is a likely place for them, being closer to
Asia. Half your luck for being able to see them.
Cheers,
Jill
Jill Dening
Sunshine Coast, Queensland, Australia
26° 51' 41"S 152° 56' 00"E
On 15/03/2011 7:43 PM, martin cachard wrote:
Hi Jill& others
I have read about your tern counts Jill with great interest.
Do you have any records in recent times on the Sunshine Coast of
afinnis Gull-billed Terns amongst the visiting terns you've surveyed?
Myself& Adam Arnold first noticed them here in Cairns amongst the
visiting Aussie breeding Gull-bills in very small numbers in October
2007 (3 birds). We have had them here in small numbers in summers
since, but the most we've had on the Cairns Esplanade site at any time
is 4 birds. They arrive late October& have usually gone by early March
(there are none here at the moment).
Very curious if you get them down there with any regularity....??
Cheers
Martin Cachard
Cairns
0428 782 808
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