Record Details

Evaluating Multi-Level Models to Test Occupancy State Responses of Plethodontid Salamanders

ScholarsArchive at Oregon State University

Field Value
Title Evaluating Multi-Level Models to Test Occupancy State Responses of Plethodontid Salamanders
Names Kroll, Andrew J. (creator)
Garcia, Tiffany S. (creator)
Jones, Jay E. (creator)
Dugger, Katie (creator)
Murden, Blake (creator)
Johnson, Josh (creator)
Peterman, Summer (creator)
Brintz, Ben (creator)
Rochelle, Michael (creator)
Date Issued 2015-11-30 (iso8601)
Note To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by the Public Library of Science. The published article can be found at: http://www.plosone.org/
Abstract Plethodontid salamanders are diverse and widely distributed taxa and play critical roles in ecosystem processes. Due to salamander use of structurally complex habitats, and because only a portion of a population is available for sampling, evaluation of sampling designs and estimators is critical to provide strong inference about Plethodontid ecology and responses to conservation and management activities. We conducted a simulation study to evaluate the effectiveness of multi-scale and hierarchical single-scale occupancy models in the context of a Before-After Control-Impact (BACI) experimental design with multiple levels of sampling. Also, we fit the hierarchical single-scale model to empirical data collected for Oregon slender and Ensatina salamanders across two years on 66 forest stands in the Cascade Range, Oregon, USA. All models were fit within a Bayesian framework. Estimator precision in both models improved with increasing numbers of primary and secondary sampling units, underscoring the potential gains accrued when adding secondary sampling units. Both models showed evidence of estimator bias at low detection probabilities and low sample sizes; this problem was particularly acute for the multi-scale model. Our results suggested that sufficient sample sizes at both the primary and secondary sampling levels could ameliorate this issue. Empirical data indicated Oregon slender salamander occupancy was associated strongly with the amount of coarse woody debris (posterior mean = 0.74; SD = 0.24); Ensatina occupancy was not associated with amount of coarse woody debris (posterior mean = -0.01; SD = 0.29). Our simulation results indicate that either model is suitable for use in an experimental study of Plethodontid salamanders provided that sample sizes are sufficiently large. However, hierarchical single-scale and multi-scale models describe different processes and estimate different parameters. As a result, we recommend careful consideration of study questions and objectives prior to sampling data and fitting models.
Genre Article
Access Condition http://creativecommons.org/licenses/by/3.0/us/
Identifier Kroll, A. J., Garcia, T. S., Jones, J. E., Dugger, K., Murden, B., Johnson, J., ... & Rochelle, M. (2015). Evaluating Multi-Level Models to Test Occupancy State Responses of Plethodontid Salamanders. PLoS ONE, 10(11), e0142903. doi:10.1371/journal.pone.0142903

© Western Waters Digital Library - GWLA member projects - Designed by the J. Willard Marriott Library - Hosted by Oregon State University Libraries and Press