Sierra Nevada Aquatic Research Laboratory

15 Aug, 05 AM - 30 Sep, 05 AM

RESEARCH OBJECTIVES, HYPOTHESES, & JUSTIFICATION The proposed work will examine the behavioral mechanisms underlying differential chipmunk range shifts in the Sierras. More specifically, my goal is to examine the interactions between each of the focal species behavior and physiology to determine the reason for their strikingly different patterns of response. I will test whether T. speciosus has more behavioral coping strategies than T. alpinus when confronted with a heat challenge and will use stress hormones (glucocorticoids, GCs) to quantify how stressful heat is to each species. I will also work on the application of an activity-logging collar for remotely measuring chipmunk behavior. I hypothesize that T. alpinus is more sensitive to high temperatures than T. speciosus and predict that in response to a heat challenge (P1) T. speciosus will exhibit higher magnitude changes in behavior from baseline (P2) T. alpinus will exhibit higher magnitude changes in GCs from baseline. For the activity-logging collar study, I expect to find consistent correlations between accelerometer readings and behaviors. Critically, VESR funding would allow me to house animals and conduct experimental work at SNARL and would also support my purchase of activity-logging collars. SNARL is centrally located in relation to my field sites and working there would allow me to house my focal animals near to where they live in the wild so that I can simultaneously conduct fieldwork and field station work, and can release animals back into their natural habitats immediately upon completion of the work. Additionally, the lab freezer is essential to reliably storing fecal samples and electricity is critical for collecting and analyzing behavioral videos. Lastly, my validation study for the activity logging collars depends on regular access to a computer so that I can conduct the statistical analyses necessary to fine-tune the accelerometer readings and determine whether the validation study is working. EXPERIMENTAL DESIGN AND METHODS Prior Work & Logistics: I have trapped and worked with captive chipmunks in the summer of 2012 and know that my proposed sample sizes and studies are feasible. The Inyo National Forest permit for trapping at these sites was attained last year and is currently being renewed. IACUC has approved most of the proposed work and approval is pending (but expected) for a few final details. Study Sites, Trapping & Handling: Grids of 150 metal Sherman traps will be set out along elevational gradients at sites in Inyo Co., CA (see above for details). All captured animals will be ear-tagged, weighed, measured, and reproductive status will be assessed. A subset of trapped adult animals will be transported back to SNARL and housed in the stations animal housing facility. Accelerometer Collars: I am collaborating with a biomechanics graduate student to develop accelerometer logger collars, consisting of a tri-axial accelerometer and a time-stamped data logger, which would record when animals are active. The collars are based on the design of Byrnes et al. 2011 (22) and have already been successfully implemented in other species at UC Berkeley, however, our collars have two novel developments: they use a logger (instead of radio-transmission) and they are <1.5 grams. At a minimum, these collars can convey when an animal is or is not moving, however, with the appropriate validation study the accelerometer data may also be used to make finer-grained behavioral distinctions (for example, running, foraging, grooming, climbing, etc.). I will conduct a validation study by fitting collars to animals (n=10 per species) and filming them in a naturalistic arena while collecting accelerometer data. Videos will be scored according to a pre-existing ethogram and statistical techniques (see below) will be used to identify correlations between behavioral data and accelerometer data. If consistent correlations are identified, activity-logging collars may be reliably used in the wild in future field seasons to explore how animals behaviorally adjust to natural variation in temperature in the field. Heat Challenge Study: Animals (n=10-15 per species) will be placed in a 4 by 3 acrylic arena fitted with thermostatically controlled, ceramic (non-light-emitting) heat lamps. iButton data-loggers will record temperature data every three seconds from three different locations in the arena. The arena will be equipped with natural substrate (wood chips/pine duff), a place to burrow/hide (nesting unit), food, water, and an item to climb or hide beneath (small tree branch). Between animals the arena will be emptied and cleaned with 10% bleach spray and its contents replaced. Each animal will be filmed for two hours at a standardized period (between 12:00-16:00) on both a baseline (no heat) day and a treatment (heat) day, on which there will be one hour without heat and one hour with heat (94F). Videos will be scored according to a pre-determined ethogram. Baseline and pre-stress behavioral data will be compared with during-stress data. I will use measurements of change in percent time spent on specific behaviors to quantify behavioral flexibility in response to heat. Behaviors of interest will include inactivity, eating/drinking, body spreading (for heat dispersal), and use of shade. Stress Hormone Assessment: Measuring fecal GCs is a non-invasive way to quantify stress in animals (15). GCs have been used to assess animal response to a broad range of environmental changes and, importantly, many studies suggest that they may correlate with reproductive success and survival (16-20). I will collect fecal samples from animals before and after exposure to heat to quantify how stressful the challenge was for each species. Later I will dry, extract, and assay samples according to modified methods from Montiglio et al. 2012 (21).

Visit #31688 @Sierra Nevada Aquatic Research Laboratory

Approved

Under Project # 27162 | Research

Captive chipmunk work at SNARL

graduate_student - University of California, Berkeley

Reservation Members(s)

Tali Hammond Aug 15 - Sep 30, 2013 (47 days)
Group of 5 Research Assistant (non-student/faculty/postdoc) Aug 15 - Sep 30, 2013 (47 days)

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Lodging (monthly first person) 1 Aug 26 - Sep 25, 2013
Lodging (monthly additional person) 3 Aug 26 - Sep 25, 2013
Laboratory space (monthly) 1 Aug 15 - Sep 15, 2013
Laboratory space (daily) 1 Sep 16 - 30, 2013
Lodging (nightly) 3 Aug 15 - 25, 2013
Lodging (nightly) 4 Sep 26 - 27, 2013
Lodging (nightly) 3 Sep 28 - 29, 2013