|Adult female in Kings Canyon|
Bufo canorus Camp, 1916
The Yosemite toad (Anaxyrus canorus, formerly Bufo canorus) is a species of true toad in the family Bufonidae. Endemic to the Sierra Nevada of California, the species ranges from the Alpine County to Fresno County. Yosemite toads show an elevational range of 1,950–3,445 m (6,398–11,302 ft) asl.
They are the most sexually dichromatic anuran in North America, with males and females displaying strikingly divergent patterns and coloration at maturity. Adult toads are long-lived with upper age limit at least 15 years, likely an adaptation to their seasonal, high-elevation environment.
The Yosemite toad utilizes montane meadows, sub-alpine meadows, riparian areas, and the surrounding forest matrix, but seldom moves further than 100 meters from water. They are explosive breeders, migrating to breeding pools and flooded areas in late spring while snowbanks still veil the frozen meadows. Males intermittently give an advertisement call from pool margins, under logs, or inside willows to attract females. Their specific name, canorus (meaning "melodious"), reflects the tuneful and pleasant sound produced by this species. When females arrive, they are immediately grasped in amplexus by one or multiple males as the males fight for a limited number of mating opportunities. Breeding sex ratios can be very skewed toward males since females may not breed every years. While in amplexus, females will lay one or more clutches of 1,500 to 2,000 eggs. Females remain for few days, males for few weeks.
Yosemite toads have declined substantially in distribution and abundance across their restricted range. They are assesses as "Endangered" by the International Union for Conservation of Nature (IUCN), are protected by the Endangered Species Act (ESA), and are a California species of special concern.
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