about six seconds. Calling males are often outnumbered by satellite males which opportunistically mate with approaching females. Amplexus takes place and a clutch of about 4,500 eggs is laid in shallow water. The eggs take three to six days to hatch and the development period of the tadpoles before metamorphosis depends largely on the water temperature. The tadpoles probably feed on algae and other organisms attached to underwater surfaces but the diet of adults has not been studied. The toads are nocturnal, spending the day in sandy burrows. They enter a state of torpor and remain underground from about September to February. They may live for four or five years and the main cause of mortality is probably predation, with raccoons (Procyon lotor), a medium-sized plover the killdeer (Charadrius vociferus), and the wandering garter snake (Thamnophis elegans vagrans) feeding on the toads. Status The population size of the Arizona toad is believed to be decreasing at a slow rate, probably due to human disturbance of their habitat, and in some localities, such as central Arizona, they are being replaced by Woodhouse's toad (Anaxyrus woodhousii). One threat faced by the Arizona toad is hybridization between these two species. They occupy similar habitat but theoretically should not hybridise because they breed at different seasons. However the male Arizona toad has occasionally been observed to mate with the female Woodhouse's toad. The Arizona toad has also been known to attempt mating with the Great Basin spadefoot toad (Spea intermontana), the Great Plains toad (Bufo cognatus), the red-spotted toad (Bufo punctatus), the canyon tree frog (Hyla arenicolor), the American bullfrog (Lithobates catesbeiana), and the lowland leopard frog (Lithobates yavapaiensis). The Arizona toad has a wide range and is assumed to have a large total population. It is an adaptable species and able to tolerate some degree of habitat modification so the International Union for Conservation of Nature has assessed it as being of "least concern". References Anaxyrus Amphibians of the United States Endemic fauna of the United States Amphibians described in 1867 Taxa named by Edward Drinker Cope Taxonomy articles created by Polbot