Geology topics

Staci Amburgey

Publications and source records attributed to Staci Amburgey.

3 recordsLinked to original sources

USGS2014

The effects of hydropattern and predator communities on amphibian occupancy

Complex, interactive ecological constraints regulate species distributions, and understanding these factors is crucial for predicting species persistence. We used occupancy analysis, which corrects for imperfect detection, to test the importance of abiotic and biotic habitat and landscape factors on probability of occupancy by Boreal Chorus Frog ( Pseudacris maculata (Agassiz, 1850)) tadpoles. We hypothesized that hydropattern and predators are primarily important because they affect desiccation and predation risk and can interact in ways difficult to predict. We surveyed 62 wetland sites across an elevational gradient in Colorado, USA, and modeled patterns in P. maculata occupancy. Tadpoles were most frequently present in intermediate-length hydropattern systems with lower desiccation risk and no predatory fish because of occasional drying. Pseudacris maculata occupancy had a strong negative relationship with fish presence, while tadpoles, odonate larvae, and Barred Tiger Salamanders ( Ambystoma mavortium mavortium Baird, 1850) frequently co-occurred. Dry seasonal conditions will likely result in fewer intermediate-length hydropattern ponds available for amphibian breeding. We hypothesize that this will force P. maculata to breed in habitats with fish. As habitats shrink, predators that co-occur with P. maculata are expected to concentrate in the remaining habitat and increase predation risk for developing tadpoles (assuming predators are similarly constricted in their habitat use as amphibians are).

Colorado↗

USGS2014

Demography of common toads after local extirpation of co-occurring midwife toads

Estimating demographic parameters like survival or recruitment provides insight into the state and trajectory of populations, but understanding the contexts influencing those parameters, including both biotic and abiotic factors, is particularly important for management and conservation. At a high elevation national park in Central Spain, common toads ( Bufo bufo ) are apparently taking advantage of the near-extirpation of the midwife toad ( Alytes obstetricans ), as colonization into new breeding ponds is evident. Within this scenario, we expected demographic parameters of common toad populations tobe affected favorably by the putative release from competition. However, we found the population growth rate was negative in 4 of 5 years at the long-standing population; survival probability at the long-standing population and newly-colonised breeding ponds was lower than reported for other toads living at high elevations and the probability of recruitment was inadequate to compensate for the survival rate in maintaining a positive trajectory for either of the breeding ponds. We assessed weather covariates and disease for their contribution to the context that may be limiting the common toad’s successful use of the niche vacated by the midwife toad.

Amphibia-Reptilia↗

USGS2012

Effects of hydroperiod duration on survival, developmental rate, and size at metamorphosis in boreal chorus frog tadpoles ( Pseudacris maculata )

Understanding the relationship between climate-driven habitat conditions and survival is key to preserving biodiversity in the face of rapid climate change. Hydroperiod—the length of time water is in a wetland—is a critical limiting habitat variable for amphibians as larvae must metamorphose before ponds dry. Changes in precipitation and temperature patterns are affecting hydroperiod globally, but the impact of these changes on amphibian persistence is poorly understood. We studied the responses of Boreal Chorus Frog ( Pseudacris maculata ) tadpoles to simulated hydroperiods (i.e., water level reductions) in the laboratory using individuals collected from ponds spanning a range of natural hydroperiods (Colorado Front Range, USA). To assess the effects of experimental hydroperiod reduction, we measured mortality, time to metamorphosis, and size at metamorphosis. We found that tadpoles grew at rates reflecting the hydroperiods of their native ponds, regardless of experimental treatment. Tadpoles from permanent ponds metamorphosed faster than those from ephemeral ponds across all experimental treatments, a pattern which may represent a predation selection gradient or countergradient variation in developmental rates. Size at metamorphosis did not vary across experimental treatments. Mortality was low overall but varied with pond of origin. Our results suggest that adaptation to local hydroperiod and/or predation and temperature conditions is important in P. maculata . Moreover, the lack of a plastic response to reduced hydroperiods suggests that P. maculata may not be able to metamorphose quickly enough to escape drying ponds. These results have important implications for amphibian persistence in ponds predicted to dry more quickly due to rapid climate change.

Herpetologica↗