thumbnail

Life history plasticity does not confer resilience to environmental change in the mole salamander (Ambystoma talpoideum)

Oecologia

Courtney L. Davis; David A.W. Miller; Susan C. Walls; William J. Barichivich; Jeffrey Riley; Mary E. Brown
By:
https://doi.org/10.1007/s00442-017-3810-y

Links

Abstract

Plasticity in life history strategies can be advantageous for species that occupy spatially or temporally variable environments. We examined how phenotypic plasticity influences responses of the mole salamander, Ambystoma talpoideum, to disturbance events at the St. Marks National Wildlife Refuge (SMNWR), FL, USA from 2009 to 2014. We observed periods of extensive drought early in the study, in contrast to high rainfall and expansive flooding events in later years. Flooding facilitated colonization of predatory fishes to isolated wetlands across the refuge. We employed multistate occupancy models to determine how this natural experiment influenced the occurrence of aquatic larvae and paedomorphic adults and what implications this may have for the population. We found that, in terms of occurrence, responses to environmental variation differed between larvae and paedomorphs, but plasticity (i.e. the ability to metamorphose rather than remain in aquatic environment) was not sufficient to buffer populations from declining as a result of environmental perturbations. Drought and fish presence negatively influenced occurrence dynamics of larval and paedomorphic mole salamanders and, consequently, contributed to observed short-term declines of this species. Overall occurrence of larval salamanders decreased from 0.611 in 2009 to 0.075 in 2014 and paedomorph occurrence decreased from 0.311 in 2009 to 0.121 in 2014. Although variation in selection pressures has likely maintained this polyphenism previously, our results suggest that continued changes in environmental variability and the persistence of fish in isolated wetlands could lead to a loss of paedomorphosis in the SMNWR population and, ultimately, impact regional persistence in the future.

Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Life history plasticity does not confer resilience to environmental change in the mole salamander (Ambystoma talpoideum)
Series title:
Oecologia
DOI:
10.1007/s00442-017-3810-y
Volume:
183
Year Published:
2017
Language:
English
Publisher:
Springer
Contributing office(s):
Wetland and Aquatic Research Center
Description:
11 p.
First page:
739
Last page:
749