DOI: 10.5061/dryad.bnzs7h4gm
title: Movement and nutritional data of mule deer in Western Wyoming (December 2013–December 2021)

description: For species that inhabit environments where resource availability may be
 unpredictable, balance of resource allocation to life-history traits can
 have heightened consequences for survival, reproduction, and ultimately,
 fitness. Acquisition and allocation of energy to maintenance, capital
 gain, and reproduction should be in tune with the landscape an animal
 inhabits—environmental severity, food availability, and population size
 all influence the resources animals have and dictate the ways they should
 be allocated. In seasonal environments, animals that experience periods of
 extreme resource limitation (e.g., harsh winters) may favor allocation of
 resources to body reserves to secure their survival at the cost of
 reproduction (i.e., risk-averse). In contrast, the same accumulation of
 body reserves may not be necessary to survive in relatively benign
 landscapes where instead, allocation to reproduction is favored (i.e.,
 risk-prone). According to theory of risk-sensitive allocation of
 resources, when animals are exposed to unprecedented or life-threatening
 conditions, they may shift resource allocation to favor building capital
 over allocation in reproduction to preempt against encountering another
 life-threatening event in the future. Using data from a long-term project
 on a highly site-faithful and long-lived species, mule deer (Odocoileus
 hemionus), we evaluated how a life-threatening winter and the associated
 changes in resource availability resulting from a population reduction
 influenced how animals acquired and allocated energy to survival (i.e.,
 fat accumulation). Per capita precipitation, and the associated reduction
 in population abundance after the severe winter, had a positive influence
 of accrual of fat over summer. After the extreme physiological stress of a
 hard winter, deer starting spring with low body reserves accumulated 2.8
 percentage points more fat over summer compared with before the experience
 of a bad winter and had an increased probability of recruiting fewer
 offspring. Fat stores can interact with environment, life-history, and
 behavior to influence survival during periods of resource scarcity. For a
 long-lived herbivore, we documented shifts in risk tolerance associated
 with fat accrual in preparation for winter, supporting the notion that
 risk-sensitive allocation of resources may be plastic–an essential
 adaptation for animals to cope with rapidly changing landscapes.
description: Animal Capture and Handling In March 2013,
 we captured 70 adult, female mule deer using helicopter net gunning. Each
 year following that initial capture event, we recaptured surviving
 individuals and captured new individuals to maintain a sample size of 70
 animals in mid-March (i.e., spring) and early December (i.e., autumn)
 until December 2021. At the initial capture of any new animal, we
 extracted one incisiform canine to estimate age using cementum annuli
 (LaSharr et al. 2023a). At each capture event, we collected data on
 nutritional condition, measured body mass, and fit all animals with a GPS
 radiocollar programmed to take satellite fixes every 2 hours (Advanced
 Telemetry Systems, Isanti, Minnesota, USA, Telonics, Mesa, Arizona, USA,
 and Vectronic Aerospace, Berlin, Germany). GPS radiocollars weighed ≤ 2 kg
 (~3.0% of adult body mass in spring and ~2.6% of adult body mass in
 autumn).We measured nutritional condition using protocols for mule deer
 which include measuring subcutaneous rump fat via ultrasonography and body
 palpation to estimate a body condition score (Stephenson et al. 2002; Cook
 et al. 2007). Using body mass, body condition score, and maximum thickness
 of rump fat via ultrasonography, we then estimated ingesta-free body fat
 (hereafter, ‘body fat’; Cook et al. 2010). We calculated over-summer
 change in fat by subtracting the body fat of each animal in autumn from
 their body fat in spring. Each spring capture, we determined pregnancy and
 fetal number of each animal via ultrasonography (Aikens et al. 2021). All
 capture and handling were done under compliance with a protocol approved
 by an Institutional Animal Care and Use Committee at the University of
 Wyoming (Wyoming Range 20131111KM00040, 20151204KM00135, 20170215KM00260,
 20200305KM00412), and were in accordance with guidelines of the American
 Society of Mammologists (Sikes 2016). Survival and
 Recruitment Monitoring To account for the energetic
 cost of raising offspring, we determined recruitment status of radiomarked
 females each autumn. We determined presence and number of dependent young
 for collared females each autumn (mid – late November). In 2013 and 2014,
 all recruitment was evaluated using visual observations. We watched marked
 females for 5–10 minutes using binoculars or spotting scopes to identify
 recruitment status based on maternal behavior (Monteith et al. 2014).
 Maternal behaviors included close association, suckling or attempted
 suckling, and any other evidence of maternal care. Each observation was
 classified with a confidence level of “low,” “medium,” or “high” based on
 evidence of maternal behaviors and group dynamics. For observations
 considered “low” or “medium” confidence, we returned to the site at a
 later day to make additional observations until the confidence level was
 “high”.  No “low” or “medium” observations were included in our analyses. 
 Additionally, during autumn captures, we validated our observational data
 by confirming evidence of lactation by palpating the udder (Monteith et
 al. 2014, Stephenson et al. 2020). During 2015 – 2021,
 we collared neonates of collared females each spring as an additional
 component of the long-term research project. Detailed methodology on
 capture and handling of neonates can be found elsewhere (Aikens et al.
 2021). In instances where all neonates of a marked female were captured
 and collared (i.e., if a female was pregnant with 2 fetuses and 2 neonates
 were captured and collared), we used known fate from the juvenile collars
 to determine recruitment status of adult females each autumn. For any
 animals in which we were not successful in capturing all neonates in a
 litter, we used the aforementioned protocol to determine recruitment
 status. Environmental Covariates and Population
 Estimates To determine the role of population density
 and habitat on accumulation of capital over summer, we evaluated the
 influence of moisture, vegetative biomass, and metrics of greenness from
 NDVI. First, we estimated seasonal home ranges of each animal using
 Brownian Bridge movement models (Sawyer et al. 2009). We estimated 95%
 summer home ranges for each animal in each summer from 1 June to 30
 August. 
description: # Movement and nutritional data of mule deer in Western Wyoming (December
 2013–December 2021) This dataset includes movement and nutrition data of
 mule deer collected in western Wyoming, USA from December 2013 to December
 2021. ## Description of the Data and file structure The movementdata.txt
 file includes the following columns: id, mst, x, and y. ID represents the
 unique id for the animal, mst is the collection date (MST) of the movement
 data, and x and y represent the x and y coordinates of the data. The
 projection of the data is NAD83 / UTM zone 12N - EPSG:26912. The movement
 data was saved as a .txt file to not truncate data when opened in Excel
 because it has &gt; 1,000,000 rows. The first column in the .txt file
 indicates the row number. The nutritiondata.csv file includes the
 following columns: id, year, change, SpringFat, Age, and Recruitment. * id
 represents the unique id for the animal. * Spring Fat represents the
 ingesta-free body fat of the animal when it was captured in March (unit is
 % body fat; e.g., 15.7 is 15.7% body fat). * change represents the over
 summer change in fat between March and December of a given year (unit is %
 body fat; e.g., -2 represents an animal lost 2% of body fat over summer
 and 10 represents an animal that gained 10% body fat over summer). * Age
 represents the age of the animal at the December capture event (unit is
 years; e.g., 7.75 is 7.75 years old). * Recruitment represents the number
 of offspring that a female deer raised until the autumn (mid November) of
 each year (unit is number of offspring; e.g., 1 represents 1 offspring
 raised to autumn) ## Sharing/access Information Please contact Kevin
 Monteith (kmonteit@uwyo.edu) or Tayler LaSharr (tlasharr@uwyo.edu) for
 questions related to the data.