

^T>" 



Madro-Tertiary Flore 



PLEISTOCENE 



PLIO- 

 CENE 



MIO- 

 CENE 



FIG. 26-5 Changes In the relative proportions of different type 

 (from Axelrod 1950). 



ohave desert regi 



*Red-taiIed hawk 

 Harris' hawk 

 Caracara 

 Gambel's quail 

 Mourning dove 

 White- winged dove 

 Ground dove 

 Roadrunner 

 *Great horned owl 

 Elf owl 



Lesser nighthawk 

 Costa's hummingbird 

 Gilded flicker 

 Gila woodpecker 

 Ladder-backed wood- 

 pecker 



Birds 



Wied's crested flycatcher 

 Vermilion flycatcher 

 Verdin 

 Cactus wren 

 Bendire's thrasher 

 Curve-billed thrasher 

 LeConte's thrasher 

 *Crissal thrasher 

 Black-tailed gnatcatcher 

 Phainopepla 

 *Loggerhead shrike 

 Lucy's warbler 

 Abert's towhee 

 *Black-throated sparrow 



Chuckwalla 



Zebra-tailed lizard 



Fringe-toed lizard 



Spiny lizards 



* Side-blotched uta 



Long-tailed uta 



Tree uta 



*Desert horned toads 



Desert gila monster 



Night lizard 



*Whip-tailed lizard 



Western blind snake 

 Boa snake 

 Whip snake 

 Leaf-nosed snake 

 *Bull snake 

 Common king snake 

 Western shovel-nosed 



snake 

 Mojave rattlesnake 

 Diamond rattlesnake 

 Sidewinder rattlesnake 



In addition to these, several species from the de- 

 ciduous forest-edge, woodland, and chaparral pene- 

 trate into the desert. Bird populations are very low 

 in the open desert (0-37 pairs/40 hectares or 100 

 acres) but may reach 108 pairs per 40 hectares in 

 washes or near water where there is a greater diver- 

 sity of vegetation (Miller 1951, Hensley 1954, Dixon 

 1959). 



Gopher turtle 

 Banded gecko 



Reptiles 



Crested lizard 

 * Leopard lizard 



The list of reptiles is compiled from the studies 

 of Mosauer (1935), Dice (1939), Huey (1942), and 

 Johnson et al. (1948). Amphibians are not common, 

 but the red-spotted toad occurs in small ponds. Little 

 quantitative investigation has been made of the in- 

 vertebrate populations of desert scrub, but grass- 

 hoppers and other orthopterans are especially con- 

 spicuous (Tinkham 1948), and the scorpion and 

 tarantula spider are much in evidence. 



BASIN SAGEBRUSH BIOCIATION 



This community inhabits both the shad- 

 scale and sagebrush associations. There is consider- 

 able overlap of species between the desert scrub and 



336 Geographic distribution of communities 



