CUCKOOS & TOURACOS

[darren.naish@port.ac.uk]

Reading the cuckoo phylogeny paper by Hughes that I mentioned the 
other day (ZJLS 130: 263-307), remembered some other recent papers 
on the same subject. Is worth collating the lot, as the neornithine tree is 
finally coming together and there are interesting areas of controversy. 

Hughes (2000) argues that parasitic cuculids form a clade, and that 
parasitism evolved once in cuculids. Inclusion of _Coccyzus_ - a 
facultative parasite - in this parasitic clade (Hughes' Cuculinae) 
implies that the earliest _Coccyzus_ was an obligate nest parasite like 
other members of its clade (taperins, eudynamins, other coccygins and 
cuculins). Cuculin cuculines are the only cuculids where the nestlings 
eject the host offspring fromthe nest. The non-parasitic, terrestrial 
cuculid clades of both the Old and New Worlds (Carpococcystinae,   
Centropodinae, Neomorphinae, Crotophaginae and Phaenicophaeinae) 
have basal positions on Hughes' tree.

Aragon et al. (2000) used mtDNA to reconstruct cuculid phylogeny. In 
their tree, neomorphines and crotophagines formed a clade and, in 
contrast to Hughes' tree, _Tapera_ and _Dromococcyx_ were close to 
this clade (in the Hughes tree the Taperini is the basal tribe of the 
Cuculinae). Their inclusion of the parasitic _Clamator_ in a clade with 
_Coccyzus_ and some non-parasitic cuckoos led Aragon et al. to argue 
that brood parasitism had evolved in this clade independently of that 
seen in other cuculines. Overall the Hughes and Aragon et al. tree seem 
to agree as to the general picture AND with the traditional view (where 
neomorphines and centropodines are more basal than phaenicophaeines 
and all are less recently evolved than cuculines) - it is in the details, or, 
in other words, the problematic taxa, that they differ.

Aragon, S., Moller, A.P., Solfer, J.J. and Soler, M. 2000. Molecular 
phylogeny of cuckoos supports a polyphyletic origin of brood 
parasitism. _Journal of Evolutionary Biology_ 12: 495-506.

As noted before, Hughes grouped touracos and hoatzins as sister-taxa, 
and the sister-taxon to Cuculiformes. Further resolution of touraco 
phylogeny has recently been provided by Veron (2000). Veron found 
that extant musophagids fall into two clades - grey touracos 
(_Crinifer_ and _Corythaixoides_) and _Coythaeola_ + turacine-
bearing touracos (_Tauraco_, _Musophaga_, _Ruwenzorornis_ and 
_Gallirex_) [turacine/touracine is a green pigment exclusive to 
touracos]. Within this phylogeny, _Corythaixoides_ is paraphyletic to 
_Crinifer_ and _Ruwenzorornis_ and _Gallirex_ are closer to 
_Tauraco_ than to _Musophaga_. 

Veron, G. 2000. Phylogenie des touracos (Aves, Musophagidae). 
Analyse des caracteres morphologies. _Journal of Zoological 
Systematics and Evolutionary Research_ 37: 39-48.

Where fossils and other neornithine clade would fit into all this would 
be interesting. Are trogons related to the opisthocomiform - 
cuculiform clade? Does the nesting of _Opisthocomus_ within a clade 
where hoatzins and touracos are sister-taxa mean that basal touracos 
had free fingers, like _Opisthocomus_, or is this unique to this genus? 
And is Chandler's hypothesis of an affinity between touracos and 
vulturids and phorusrhacoids untenable in parsimony analysis? Oh 
well, more work to come I suppose.

Wind, rain, wind, rain, wind, rain, and some more wind and rain.

DARREN NAISH 
PALAEOBIOLOGY RESEARCH GROUP
School of Earth, Environmental & Physical Sciences
UNIVERSITY OF PORTSMOUTH
Burnaby Building
Burnaby Road                           email: darren.naish@port.ac.uk
Portsmouth UK                          tel: 01703 446718
P01 3QL