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

Washington Project

Integrated abundance and movement models for marine mammals

September 2018 - March 2021


Participating Agencies

  • North Pacific Research Board

Capture-recapture and telemetry methods are frequently used to evaluate marine mammal density, habitat use, and movement, providing important information on sustainable harvest, the effects of a warming environment, and spatial and temporal overlap with commercial fisheries. In general, capture-recapture methods provide population-level demographic parameters, while telemetry methods provide individual level information on habitat use, movement, and behavior. Although the two approaches share information on population dynamics, the resulting data are generally analyzed separately, which can lead to inefficient estimators and substantial bias. We propose development of a framework for integrating spatial capture–recapture (SCR) and telemetry data to simultaneously estimate density, habitat use, and movement of marine mammals. Integrated SCR telemetry models have the potential to (1) address shortcomings of traditional capture-recapture methods; (2) allow estimation of abundance, density, movement, dispersal, and habitat selection using all available data; and (3) be applied across a variety of study designs used for marine mammal monitoring. We propose to develop SCR-telemetry models using capture-recapture and telemetry data for polar bears in the Chukchi Sea during the period 2008 – 2016. We also propose to use simulation methods to evaluate the performance of SCR-telemetry models and provide monitoring design recommendations of broad applicability to polar bears and other marine mammals. Improved monitoring methods are critical to obtaining accurate information on polar bear abundance and distribution, which is needed for management and conservation under national laws and international agreements, and SCR-telemetry methods show great promise for providing that information. More broadly, SCR-telemetry models provide researchers and managers with a framework to integrate multiple data types – including data from
emerging technologies (e.g., satellite tags, acoustic sampling, autonomous drones) – to improve the accuracy and efficiency of marine mammal monitoring programs across the Arctic.

Research Publications Publication Date
Regehr EV, NJ Hostetter, RR Wilson, KD Rode, M St. Martin, and SJ Converse. 2018. Integrated population modeling provides the first empirical estimates of vital rates and abundance for polar bears in the Chukchi Sea. Scientific Reports 8:16780. November 2018
Hostetter NJ, NJ Lunn, ES Richardson, EV Regehr, and SJ Converse. 2021. Age-structured Jolly-Seber model expands inference and improves parameter estimation from capture-recapture data. PLOS ONE 16:e0252748. June 2021
Presentations Presentation Date
Hostetter NJ, NJ Lunn, ES Richardson, EV Regehr, and SJ Converse. 2019. Integrating age data to improve estimation of polar bear abundance, survival, and recruitment in open-population Jolly-Seber models. American Fisheries Society & The Wildlife Society Joint Conference, Reno, Nevada. 29 September - 3 October. September 2019
Hostetter NJ, EV Regehr, RR Wilson, NJ Lunn, ES Richardson, JA Royle, and SJ Converse. 2020. Data integration approaches to estimate polar bear abundance, survival, movement, and recruitment. Alaska Marine Science Symposium, Anchorage, Alaska. 27-31 January. January 2020
Hostetter NJ, AA Yackel-Adams, SM Amburgey, WA Link, and SJ Converse. 2020. Optimizing eradication strategies for an incipient population of brown treesnakes on Cocos Island. Brown Treesnake Technical Working Group, Online. 9 Nov - 19 Nov. November 2020