Interesting report of Black-naped Terns nesting.
Well of course if the gulls did get one out of every ten chicks, then they
would have decimated them, literally. Decimation is not devastation,
decimation is a rather trivial event in natural populations, unless it is
done repeatedly. All other factors remaining equal, decimation needs to
occur 7 times to halve the population i.e. 100%, 90%, 81%, 72.9%, 65.6%,
59%, 53.1%, 47.8%.)
-----Original Message-----
From: jon wren <>
To: <>
Date: Tuesday, 30 March 1999 19:36
Subject: birding-aus Black naped Terns nesting.
>Gooday birders,
>During December and January this year a group of Black naped Terns
>nested on the long sandspit of Stone Island, just offshore from Bowen
>Queensland, for International subscribers the location is the "Top of
>the Whitsundays".
>David James reported sighting imm.BN Terns early in 1998 and thought
>there was a possibility of a mainland breeding site. The area the birds
>nested would be about 5Km SE of this site where James observed the young
>birds.
>What I found interesting was the adult birds behaviour during the
>nesting period. Quite a few adult birds would fly from the sand spit and
>fly that low over the water that they almost touched it, they always
>done two or three circuits then returned to the nest site. At this time
>the days were extremely hot so you can imagine the temperature of the
>sand spit. I concluded that the birds were cooling themselves as none of
>the birds were feeding, during the time that they were absent from the
>nest Silver Gulls would move in and actually attack and succeed in
>getting a chick, this caused great commotion.
>With hot days continuing for a further fortnight I would have expected
>the nesting site to be decimated, but actually they have succeeded in
>raising a number of young. All observations were from a dinghy and I was
>pleased that the locals gave the island a wide berth during this nesting
>period.
>
>Jon Wren
>PO Box 868
>Bowen
>Queensland
>Australia 4805 Phone 07 4786 2614H or
>Visit the birds of Bowen, click Tourism
>www.lgaq.asn.au/bowen.nsf
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