From all the replies, to my question below,
which have
come forward (some of which were really interesting) I don't think we
have come up with any convincing points of advantage for different
bills when waders feed on the breeding grounds. (Except the fascinating
one from Bruce about the Black-tailed Godwit taking rice, and that may
be unrelated to evolution.) As Laurie points out
the breeding birds are spread over a vast area of differing habitats.
The point of focusing on long distant migrants is because their
breeding and wintering habitats are so very different. The question
would be the same if it were the case with resident shorebirds.
There doesn't have to be a convincing reason, I just wondered if there
was one about which I didn't know.
Thanks to you all for your thoughts.
Cheers,
Jill
Jill Dening
Sunshine Coast, Queensland, Australia
26° 51' 41"S 152° 56' 00"E
Jill Dening wrote:
Hi All,
I was recently asked a question about waders which totally fazed me. I
was asked if the length of the bill of different species of wader is of
any advantage on the breeding grounds.
This came up in respect to my saying that here, where waders live in
coastal regions, the length of the bill can allow different species to
feed together in intertidal estuaries without competing. I described
the intertidal substrate as like a department store with several
floors, where different species bought their food on different floors.
And then one thinking person asked the question above.
I want to be able to get back to this person with an answer. I didn't
find any reference to it in my library. I have never been to the
breeding grounds, but there the waders are scattered over thousands of
kms, where I imagine the bill length is no competitive advantage. They
are not communal breeders. I have never heard the bill length discussed
in any context relating to the breeding grounds.
Can anyone help? Can the bill length help some species to eat certain
food on the breeding grounds?
Cheers,
Jill
--
Jill Dening
Sunshine Coast, Queensland, Australia
26° 51' 41"S 152° 56' 00"E
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