Quantitative and Other Methods

Science Center Objects

Applying quantitative methods to evaluate ecological hypotheses for wild animal populations is inherently challenging due to the complexity of ecological systems and the sampling process that is used to monitor them.

Amphibians can be especially difficult to monitor because they are often cryptic and use different habitats seasonally. Our lab uses occupancy, capture-recapture, and related analyses (using both frequentist and Bayesian approaches) to correct monitoring data for the sampling process (i.e., imperfect detection, sampling designs, etc.) and provide unbiased estimates of system dynamics. Part of this work involves publishing technical reports and peer-reviewed articles on the development and evaluation of new methods accommodating different sources of uncertainty. Examples of field methods used by our lab include environmental DNA (eDNA) sampling, capture-mark-recapture, radio telemetry, skin swabbing for disease and microbiome, water and sediment sampling, and tissue sampling for genetic analyses. We also provide decision support to identify and address the needs of diverse stakeholder groups and wildlife using a structured process.


USGS technician filters water samples for environmental DNA (eDNA)

USGS technician filters water samples for environmental DNA (eDNA) to monitor for the presence of foothill yellow-legged frogs (Rana boylii) at historically occupied sites. Photo courtesy B. McCreary. 

(Credit: B. McCreary. Free to use with credit to Brome McCreary; Ask permission before altering photo.)