I post this report because I like to
think that at least some of us are interested in such
first-hand accounts of bird behaviour (especially of species
with close relatives in Australia), and because I actually
think it's an excellent model of how amateurs like us can make
and report valuable observations.
The author, Chris Carter, is a
colleague who is currently working in Arica, at the edge of
the Atacama Desert in northern Chile. He would not describe
himself as a birder (I doubt that he has a field guide with
him), but in the light of what follows that only invites
contemplation of what it actually means to be a birder.
It does seem to me too that we could
take lessons in fish management from the Chileans (the human
ones, that is).
If this is of no interest, my
apologies for taking your time - just delete.
the third day in a row the birds have been getting into the
sardines. I think the sardine season is well under way but the
boats have not been working for the last couple of days – they
are fairly strict as to when and where the boats can fish and
stop them without notice if they think the catches are too high.
I thought you would be interested in the strategies used by the
birds. They tend to group in bunches of several hundred
scattered across several kilometres (from the 16th
floor we have a pretty broad view) just sitting on the water. A
few birds then seem to scout around until the find a school of
fish and then they start diving. This signals the groups to
take to the wing and join in. They are too far out to see
exactly what species the groups are – probably Peruvian boobies
but as soon as the feeding starts, the pelicans [Peruvian
Pelicans, IF] join in along with a few kelp gulls. The other
gulls (not sure which species, totally ash grey [Grey Gulls Larus
modestus, IF]) are shore feeders and don’t bother with
what’s happening off-shore. Yesterday the feeding birds spread
over an area more than a kilometre long. Flocks come in from
everywhere and we watched for about 20 minutes and more were
still coming in. There would have been thousands of birds in
total over a narrow spread. There were several ‘centres’ where
the feeding was taking place with the birds gaining altitude
before spiralling down to dive into the water – hundreds at a
time coming down like they were in a vortex. I don’t know how
long it went on for as we had to leave before they had
finished. It’s a wonder there are any sardines left!
Particularly as there was a pod of dolphins joining in
other observations we have made relate to the pelicans ‘surfing’
the waves. The beach here is quite shallow and the waves (1-2m)
form 100-150m off-shore in a very regular pattern. The pelicans
fly along parallel to the coast in a line about where the waves
form and as the swell rises, they will position themselves in
front of the wave and ‘surf’ the air current as it is uplifted.
Their wing tips look as if they were only a few centimetres from
the wave face. They stay with the wave until it starts to break
and then roll off, head back out and catch the next wave as it
comes in, moving along the coast all the while until they get to
where they are headed – into the sheltered waters of the port
where they roost. Sometimes individual birds will do it, other
times it will be a line of 20 or more. Quite beautiful to watch.
Ian Fraser, m("internode.on.net","calochilus51");">
Environment Tours; Vertego Environmental Consultancy
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