Re: The Hoatzin - Is It Still a Cuckoo?

[ornstn@inforamp.net (Ronald Orenstein)]

>Since birds and their relationship to dinosaurs has been a recent topic of
>discussion, I would like to ask those Avian palaeontologists out there to pass
>comment on the Hoatzin's (Opisthocomus hoatzin) place in the bird family tree. 
>
>Is it still a cuckoo? Or is it something else?
>
>Many thanks,
>
>Joseph  McKee

Well, I suppose it depends on whom you read.  For what it's worth, Sibley
and Ahlquist place it within their Cuculiformes, and provide an extensive
discussion of its taxonomic history (Phylogeny and classification of birds,
Yale UP 1990, pp.373-379) to which I refer you for details. S&A conclude on
the basis of DNA-DNA hybridization evidence that "the hoatzin is a
highly-modified cuckoo, most closely related to the Guira Cuckoo, the anis
(Crotophaga) and the roadrunners (Neomorphidae)."  Gill's 1995 text
"Ornithology" (2nd ed) accepts this placement.  The "Handbook of the Birds
of the World, vol. 2 p. 434 (1994) notes (p. 14):

"...this species has often been placed in the Galliformes, although there
has been a strong movement in recent years to transfer it to Cuculiformes, a
proposal, which, in turn, has received forceful criticism.  The answer seems
to be that nobody really knows where this species belongs, so for the time
being it has been deemed most suitable to award the Hoatzin an order of its
own, Opisthocomiformes, alongside the Galliformes, as it does not appear to
be closely related to any other living species."

So, you pays your money, you takes your choice...
--
Ronald I. Orenstein                           Phone: (905) 820-7886 (home)
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