Willet (Tringa semipalmata semipalmata)
9 April 2009, Grande Island, Jefferson Parish, Louisiana.
Same details as previous. This is a different bird with some retained
basic feathering on the back, scapulars and wing coverts. I believe this
was a female, as the presumed male was displaying overhead from telephone
lines.
Earlier I commented that the 47th AOU Check-List supplement inserted this
species between the Greater and Lesser Yellowlegs. I have been advised
that contrary to all reasonable expectations, Greater and Lesser yellowlegs
are not each others' closest relatives. Evidently the similarity is due to
convergence. Genetic data show that the Willet is more closely related to
the Lesser Yellowlegs than either is to each other.
More details at:
http://www.museum.lsu.edu/~Remsen/SACCprop227.html
Full details of the molecular and morphological study are at:
http://individual.utoronto.ca/sergiolp/pdf/Condor2005.pdf
Nevertheless, the Willet is morphologically so different that, until
recently it was placed in its own genus. I remain modestly skeptical of the
adopted arrangement and note that several alternative Bayesian tree
topologies are offered in the Condor paper. E.g. in Figure 1, the tree
using nuclear DNA differs substantially from the one using mDNA and does
not support such a close relationship between the Willet and the Lesser
Yellowlegs.
The statistical methods used to arrive at the various alternative trees are
very interesting, but when they are based on only two Willet specimens, one
of which has no date or locality information, and when the results are so
clearly at odds with common sense, I tend to remain skeptical.
Digiscoped with Panasonic DMC-LZ5 Nikon FieldScope 3 / 30X WA hand-held (no
adapter)