At 17:11 8/05/98 +0800, Frank wrote:
>>
>breeding adult Short-tailed Shearwaters from Montague Island (wherever this
>is? Bass Strait?) which were fitted with sattelite transmitters and were
>recorded flying almost to Antarctica (15,000kms round trip in 15 days).
Frank,
Shorty-tailed shearwater is by far the most abundant bird in the Southern
Ocean south of Australia and the Indian Ocean during the Austral summer (at
least from the Ross Sea to Pridz Bay, our "local" quarter of the Southern
Ocean. In fact they outstrip all other species combined by an order of
magnitude. Large flocks have been regularly recorded moving between Aus.
and the Antarctic Convergence and then westwards into the Indian Ocean
sector. They go there to feed on the famous Antarctic krill supplies. They
don't just go to Antarctica occasionally, the species relies on and has a
significant role in the Antarctic food chain. It makes sense really, how
else could a bird breeding on a tiny length of the Australain coast
maintain one of the largest populations and biomass of any bird in the world?
The amount of time that individuals spend at sea (i.e the interval between
visits to the burrow) and therefore probably the distance travelled and
just where they go depends to some extent on the stage of breeding.
The distribution map in HANZAB gives no idea of the distribution of
Short-tails in the SO. This is probably due to entrenched confusion with
Sooty Shearwater which some workers still believe is the common shearwater
in these sectiors of the SO
Radio tagging corroborates evidence of Short-taileds travelling to
Antarctica gained from direct observations in the Southern Ocean. The
Australian Antarctic Division has an enormous data set on the seabird
distribution, abundance and movements in the SO along with phenomenal
amounts of oceanographic and meteorological data. in fact, the data-set is
so good that it may answer a few of the notorious "why" questions as well
as the easier "what" and "where" questions. Unfortunately, the last I heard
the data was not being analysed.
Montsague I. is in NSW, off Narooma.
David James
PO BOX 5225
Townsville Mail Centre 4810
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