U.S. Department of Agriculture: Animal and Plant Health Inspection Service


Date of this Version

May 1996




Little is known about the longevity of amphibians in nature. Records from captive specimens have demonstrated life spans of 10 to 20 yr for a number of anuran species, including 36 yr for Bufo bufo (Duellman WE, Trueb L. 1986. Biology of Amphibians. New York: McGraw-Hill. 670 p). Here, we report on a male Woodhouse's toad (Bufo woodhousii) which appeared in 1978, and has apparently remained since, in a basement window well of a brick home in an unincorporated western suburb of Denver, Colorado (T3S, R69W, 530). In the intervening years no other toads have been observed in any of the other window wells around the house and no distinctive differences in size and appearance of this toad have occurred, which makes it unlikely that multiple animals over time could have been assumed to be a single individual. This individual has now been observed continuously during the warmer months for 19 yr. Although we cannot know its age when it first dropped into the window well, it is likely that this individual exceeds 20 yr of age. The site in which this toad trapped itself is well protected or removed from most potential predator species and offers reliable food sources (insects, spiders, earthworms), factors which undoubtedly provide optimal circumstances for maximal longevity. The window well structure is in a small garden along the east face of the home. A 1.5 m wooden fence to the south protects it from the sun, while a nearby faucet provides moisture from early spring through mid-fall.