Pennsylvania Project: Incorporating radio telemetry data in tag-return studies

Pennsylvania Project

Incorporating radio telemetry data in tag-return studies

August 2010 - May 2013

Personnel

Participating Agencies

Pennsylvania Game Commission

White-tailed deer have been captured and either ear-tagged with reward tags or radio collars. Because capture occurs in winter (Jan-Apr) and harvest doesn't occur until autumn, mortality between capture and harvest is estimated from radio-collared deer. We are evaluating how these data can be combined to provide more accurate and precise estimates of harvest rates.

Research Publications

Research Publications	Publication Date
Buderman, F. E., D. R. Diefenbach, M. J. Casalena, C. S. Rosenberry, B. D. Wallingford. 2014. Accounting for tagging-to-harvest mortality in a Brownie tag-recovery model by incorporating radio-telemetry data. Ecology and Evolution 4:1439-1450. \| Abstract \| Download \| Publisher Website	March 2014	The Brownie tag-recovery model is useful for estimating harvest rates but assumes all tagged individuals survive to the first hunting season; otherwise, mortality between time of tagging and the hunting season will cause the Brownie estimator to be negatively biased. Alternatively, fitting animals with radio transmitters can be used to accurately estimate harvest rate but may be more costly. We developed a joint model to estimate harvest and annual survival rates that combines known-fate data from animals fitted with transmitters to estimate the probability of surviving the period from capture to the first hunting season, and data from reward-tagged animals in a Brownie tag-recovery model. We evaluated bias and precision of the joint estimator, and how to optimally allocate effort between animals fitted with radio transmitters and inexpensive ear tags or leg bands. Tagging-to-harvest survival rates from >20 individuals with radio transmitters combined with 50–100 reward tags resulted in an unbiased and precise estimator of harvest rates. In addition, the joint model can test whether transmitters affect an individual's probability of being harvested. We illustrate application of the model using data from wild turkey, Meleagris gallapavo, to estimate harvest rates, and data from white-tailed deer, Odocoileus virginianus, to evaluate whether the presence of a visible radio transmitter is related to the probability of a deer being harvested. The joint known-fate tag-recovery model eliminates the requirement to capture and mark animals immediately prior to the hunting season to obtain accurate and precise estimates of harvest rate. In addition, the joint model can assess whether marking animals with radio transmitters affects the individual's probability of being harvested, caused by hunter selectivity or changes in a marked animal's behavior.

Theses and Dissertations

Theses and Dissertations	Publication Date
Buderman, F. E. 2012. A joint Kaplan-Meier known-fate and Brownie tag-recovery model to estimate harvest and survival rates. M.S. Thesis, Pennsylvania State University, University Park, Pennsylvania.	December 2012

Cooperative Fish and Wildlife Research Units Program: Pennsylvania Education, Research and Technical Assistance for Managing Our Natural Resources

Pennsylvania Project

Incorporating radio telemetry data in tag-return studies

August 2010 - May 2013

Personnel

Participating Agencies

Cooperative Fish and Wildlife Research Units Program: Pennsylvania
Education, Research and Technical Assistance for Managing Our Natural Resources