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Current Research Projects

Life History Transmitters (LHX) in Steller sea lions: assessing the effects of health status, foraging ability, and environmental variability on juvenile survival and population trends.

Using newly developed, life-long Life History Transmitters, we will determine survival rates, causes of mortality and multi-year longitudinal dive effort in individual, free-ranging juvenile Steller sea lions (Eumetopias jubatus).

Video-based attendance patterns of Steller sea lions (Eumetopias jubatus) at the primary nursery haul-out in Oregon

We will use video cameras to record Steller sea lion attendance patterns at Sea Lion Caves in Oregon.  This method of examining maternal attendance patterns is a way to infer the availability and quality of food resources in the area.

                                                                                                                                                                                            Modeling of Pinniped Population Trends

Current approaches to determine the statistical power and significance of data collected through various methods and to estimate survival rates of animal populations of interest have substantial limitations.  We are now developing information-theoretic models for testing the power and significance of pinniped survival rate estimates using differing monitoring techniques, including the newly developed LHX transmitters. 

                                                                                                                                                                                                                                                                                                                                                             Remote infrared thermography of homeotherm animals

We are adding infrared thermography capability to our SLiDAP remote imaging system.  These measurements will be used to extend remote census operations into low-light or night-time conditions, and for the assessment of health and reproductive status of pinnipeds.  In addition, we are validating the novel application of remote thermography for the assessment of subcutaneous blubber thickness and associated body condition trends of individual seals and sea lions. 

                                                                                                                                                                Aging in Weddell Seals: Proximate mechanisms of age-related changes in adaptations to breath-hold hunting in an extreme environment.

Pinnipeds appear to avoid senescence even though their habit of hunting and exercising while holding their breath suggests them as excellent candidates for aging, giving rise to two questions: 1) What specific physiological and mophological changes occur with advancing age in pinnipeds? and 2) What subtle adjustments are made by these animals to cope with such changes? This investigation will be the first to describe specific, small-scale physiological and behavioral changes relating to dive capability with advancing age in a model pinniped.

                                                                                                                                                                     The Satellite-Linked Data Acquisition and Photogrammetry System (SLiDAP):

The SLiDAP remote imaging system consists of a local area imaging network for polar regions that is remotely accessible via satellite high-speed data link. The primary purpose of this imaging network is the performance of close-range three-dimensional photogrammetry for the quantitative assessment of biological and physical systems. Specifically, we will use SLiDAP to improve census data and remotely estimate changes in body mass and condition over time, in sea lions and seals.