SREL Reprint #0863




Structure and Dynamics of Two Breeding Populations of the Eastern Tiger Salamander, Ambystoma tigrinum

Raymond D. Semlitsch



The structure and dynamics of two populations of the eastern tiger salamander, Ambystoma t. tigrinum, were studied during four breeding seasons (1978-1982) in South Carolina.  Drift fences with pitfall traps completely encircled two breeding sites so that a census of all breeding adults and metamorphosing juveniles was achieved each year.

Breeding migrations of adults began in late October or November for males and November through February for females.  Peak immigration occurred in January or February but varied annually depending on climatic conditions.  Peak emigration occurred in either February or March.  Breeding population size and sex ratio varied annually between sites.  The largest number of adults was observed in 1978-1979 and 1981-1982 and the smallest number in 1980-1981, with an average of 87 and 24 adults for the two study sites.  Metamorphic success was apparently related to the amount of time breeding sites retained water during the larval period.  Total production of juveniles varied annually from 0 to 1,041 or at a rate of 0-23.7 juveniles per breeding female.

The physical characteristics inherent at ephemeral breeding sites and annual variation in climatic conditions may account for much of the variation in the number of breeding adults and metamorphosing juveniles.  Environmental factors that affect the drying rate of ponds were implicated as influencing the population size of A. tigrinum that breed in ephemeral ponds.


SREL Reprint #0863

Semlitsch, R.D. 1983. Structure and dynamics of two breeding populations of the eastern tiger salamander, Ambystoma tigrinum. Copeia 1983:608-616.

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