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Re: Little skulls & cuckoos

I have just finished reading The minds of Birds, by Alexander F. Skutch, which makes some interesting points about the behaviour of parasatic birds – most of which is not beyond leaving fossil evidence behind if this is what occurred with the Velociraptors in Mongolia. I made five bullet point notes as I reread that chapter:



The Minds of Birds by A. Skutch, Texas A&M University press 1996

(ISBN 0-89096-671-0)

Balda and Wiltschko 1991; Coulson 1972; Dowsett-Lemaire 1979; Howard 1952; Nice 1943; Nolan 1958, 1978, Rappole and Warner 1980; Shwartz 1963, 1964; Sherman 1952; Skutch 1953, 1954, 1976; Wall 1990; Welty 1975

Samuel Barnett

Actual headline of Saturday’s Guardian: "They were vicious, stupid and doomed, So why can’t we resist a dinosaur?"

----- Original Message -----
From: dbensen <dbensen@gotnet.net>
To: <hunt@u.washington.edu>
Cc: <dinosaur@usc.edu>
Sent: Friday, October 22, 1999 3:43 PM
Subject: Re: Little skulls & cuckoos

> >>  The cost of cuckoo-egg-rejection behavior is that occasionally a host
> bird will accidentally destroy one of its own eggs, misidentifying it as a
> cuckoo egg.  There has been a fair amount of mathematical modelling &
> field studies of the evolution of cuckoo egg rejection and it is partly a
> trade-off of "risk of accepting cuckoo egg" vs. "risk of accidental
> destruction of own egg". The risks, of course, vary with appearance &
> variation of cuckoo eggs & host eggs, alertness of the host to other cues
> (e.g. presence of a cuckoo female in the territory), cuckoo population &
> host choice by cuckoos. Ditto for other brood parasites....
>   As for symbiosis, I haven't heard of any observed benefits to hosts
> from brood parasites (pipe up, anyone), while the costs (death of
> offspring & "overworking" of parents) are well-documented.<<
> Okay, so cukoos and their hosts are in a state of dynamic equilibrium.  I had
> wondered about that, since the arrangment never seemed that stable.  How do
> the host birds raise enough chicks to maintain their population?  What keeps
> them from rejecting the chicks that obviously arn't theirs?  Now I have an
> answer.  Thanks.
> Dan