class="tbldt">0.064-0.157

0.097 0.070 0.007 0.067    Michoacán: Tafetan  21 0.103-0.157 0.128 0.039 0.009 0.186    Michoacán: Apatzingán  84 0.064-0.126 0.089 0.051 0.005 0.060               sacki occidentalis  50 0.086-0.183 0.130 0.021 0.003 0.042

 

 

From the geographically adjacent populations of sacki (sacki and occidentalis), zweifeli differs in coloration and scutellation (see Tables I-III). Cnemidophorus sacki sacki has a dorsal pattern in adult males of dark brown cross-bars on a tan ground-color. Both occidentalis and zweifeli have variable, diffuse color patterns in large adults, but zweifeli differs from occidentalis in having a blue spot on the pink throat.

Ecology.—In the arid Tepalcatepec Valley Cnemidophorus sacki zweifeli lives at elevations of 160 to 1300 meters. In the lower parts of the valley the lizards live primarily in open scrub forests, characterized by deciduous trees offering only partial shade from the sun, especially during the prolonged dry season. Common trees in this scrub forest are Acacia cymbispina, Cercidium plurifoliolatum, Mimosa distachya, and Prosopis juliflora.

During the dry season (November through May) adult males apparently aestivate; several large series collected in the winter include only subadults and females. This absence of males is corroborated by personal observations in the Tepalcatepec Valley in April and May. In the summer rainy season the lizards are active in the morning and again in the late afternoon; only Cnemidophorus calidipes is active during the heat of the midday. In some areas of the scrub forest Cnemidophorus sacki zweifeli is found in association with Cnemidophorus communis communis. Throughout the scrub forest C. sacki zweifeli occurs with C. deppei infernalis. In some of the more dense scrub forest, where C. sacki zweifeli is not so abundant as in the more open forest, it has been taken with C. lineatissimus exoristus. In the open Acacia-Cercidium associations on the valley floor C. sacki zweifeli occurs with C. calidipes.

This subspecies is not restricted to the scrub forest. On the lower slopes of the Cordillera Volcanica in Michoacán C. sacki zweifeli has been collected in open pine-oak forest near Zirimicuaro and Ziracuaretiro.

Distribution.—Cnemidophorus sacki zweifeli inhabits the valley of the Río Tepalcatepec in Michoacán and probably extreme southwestern Jalisco, and the western part of the Balsas Basin in Michoacán. No specimens have been seen from extreme western Guerrero, but C. s. zweifeli may occur there.