Iteroparity in the Variable Environment of the Salamander Ambystoma tigrinum

Authors:Wilbur, Henry, Department of BiologyUniversity of Virginia Church, Don, Department of BiologyBailey, Larissa, Department of BiologyHines, Jim, Wildlife Research CenterUS Geological Survey

Abstract. Simultaneous estimation of survival, reproduction, and movement is essential to understanding how species maximize lifetime reproduction in environments that vary across space and time. We conducted a four-year, capture–recapture study of three populations of eastern tiger salamanders (Ambystoma tigrinum tigrinum) and used multistate mark–recapture
statistical methods to estimate the manner in which movement, survival, and breeding probabilities vary under different environmental conditions across years and among populations and habitats. We inferred how individuals may mitigate risks of mortality and reproductive failure by deferring breeding or by moving among populations. Movement probabilities among populations were extremely low despite high spatiotemporal variation in reproductive success and survival, suggesting possible costs to movements among breeding
ponds. Breeding probabilities varied between wet and dry years and according to whether or not breeding was attempted in the previous year. Estimates of survival in the nonbreeding, forest habitat varied among populations but were consistent across time. Survival in breeding ponds was generally high in years with average or high precipitation, except for males in an especially ephemeral pond. A drought year incurred severe survival costs in all ponds to
animals that attempted breeding. Female salamanders appear to defer these episodic survival costs of breeding by choosing not to breed in years when the risk of adult mortality is high. Using stochastic simulations of survival and breeding under historical climate conditions, we found that an interaction between breeding probabilities and mortality limits the probability of multiple breeding attempts differently between the sexes and among populations.

Ambystoma tigrinum, breeding probability, cost of reproduction, environmental variability
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Source Citation:

Wilbur, Henry, Don Church, Larissa Bailey, and Jim Hines. "Iteroparity in the Variable Environment of the Salamander Ambystoma tigrinum." ECOLOGY 88.4 (2007): 891-903. Available: [""].

Ecological Society of America
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Sponsoring Agency:
National Science Foundation

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