We next come to the Cape St. Lucas bird, described by Mr. Xantus as P. lucasanus. Here the bill and feet become disproportionally larger and more robust than in any described; the black bands of the back larger than the white, perhaps fewer in number. The continuous red of the head also appears restricted to a stripe above and behind the eye and on the occiput, although there are some scattered feathers as far forward as above the eyes. The specimens are, however, not in very good plumage, and this marking cannot be very well defined; the red may really be as continuous forward as in the last variety. The nasal tufts are brown, as in the typical scalaris. The outer three tail-feathers in most specimens show still more white, with one or two indistinct terminal bands only on the outer two; one or two additional spots, especially on inner web, and the sub-basal patch of inner web greatly reduced. Specimens vary here in this respect, as in other races of scalaris, but the average is as described.
Notwithstanding the decided difference between typical scalaris and lucasanus, the discovery of the variety graysoni makes it possible to consider both as extremes of one species. To nuttalli, however, it is but one step farther; a restriction of the red to the posterior half of the top of head, the white instead of brown nasal feathers, and the whiter under parts being the only positive characters. The markings of the tail are almost identical with those of lucasanus. The anterior portion of the back is, however, not banded, as in the several varieties described. For this reason it may therefore be questioned whether, if lucasanus and scalaris are one, nuttalli should not belong to the same series.
We thus find that the amount of black on the tail is greatest in Southern and Southeastern Mexican specimens, and farther north it begins to diminish; in Western Mexico it is still more reduced, while at Cape St. Lucas the white is as great in amount as in the Upper Californian P. nuttalli.
The characters given above for the different varieties or races of Picus scalaris, as far as they relate to the tail, may be expressed in the following table, illustrated by the accompanying diagram, showing the markings of outer tail-feather in scalaris and nuttalli.
Outer tail-feathers with seven distinct transverse black bands.
These bands confluent on inner web near the base … var. scalaris.
Bands distinct on inner web … var. bairdi.
Bands on outer tail-feather distinct on outer webs at end only, obsolete or wanting towards base (as in nuttalli).
Tarsus, .68. Bill and legs as in average … var. graysoni.
Tarsus, .78. Bill and legs very stout … var. lucasanus.