DOI: 10.5061/dryad.m0cfxpp9t
title: Bear in mind! Bear presence and individual experience with calf survival shape the selection of calving sites in a long-lived solitary ungulate

description: The careful selection of ungulate calving sites to improve offspring
 survival is vital in the face of predation. In general, there is limited
 knowledge to which degree predator presence and prey’s individual
 experience shape the selection of calving sites. Predator presence
 influences the spatiotemporal risk of encountering a predator, while
 individual experiences with previous predation events shape perceived
 mortality risks. We used a multi-year movement dataset of a long-lived
 female ungulate (moose, Alces alces, n=79) and associated calf survival to
 test how predator presence (i.e. encounter risk) and females’ individual
 experiences with previous calf mortality events affected their calving
 site selection and site fidelity. Using data from areas with and without
 Scandinavian brown bear (Ursus arctos) predation, we compared females’
 calving site selection using individual-based analyses. Our findings
 suggest two things. First, bear presence influences calving site selection
 in this solitary living ungulate. Females in areas with bears were
 selected for higher shrub and tree cover and showed lower site fidelity
 than in the bear-free area. Second, the individual experience of calf loss
 changes females’ selection the following year. Females with lost calves
 had a lower site fidelity compared to females with surviving calves. Our
 findings suggest that increased vegetation cover may be important for
 reducing encounter risk in bear areas, possibly by improving calf
 concealment. Lower site fidelity might represent a strategy to make the
 placement of calving sites less predictable for predators. We suggest that
 bear presence shapes both habitat selection and calving site fidelity in a
 long-lived animal, whereas the effect of individual experience with
 previous calf loss varies. We encourage further research on the relevance
 of female experience on the success of expressed anti-predator strategies
 during calving periods.
description: Female moose were immobilized with a
 CO<sub>2</sub>-powered dart gun (DANiNJECT, Kolding, Denmark)
 from a helicopter with a mixture of etorphine-acepromazine-xylazine or
 etorphine-xylazine (Evans <em>et al</em>., 2012; Græsli
 <em>et al</em>., 2020; Kreeger & Arnemo, 2007; Lian
 <em>et al</em>., 2014). Each female was equipped with a neck
 collar with a global positioning system (GPS) device, including a very
 high frequency (VHF) transmitter, a global system for mobile (GSM)
 communication, an ambient temperature recorder, and an acceleration sensor
 to monitor their movement over time (Vectronic Aerospace GmbH, Berlin,
 Germany, 2022). Using the GSM network or satellite, the tracking device
 sends continuous positions to the existing database Wireless Remote Animal
 Monitoring (WRAM; Dettki <em>et al.,</em> 2014), which allows
 us to monitor females remotely in near real-time. The GPS provided
 half-hourly locations of the moose females, which we resampled for the
 habitat selection analysis to four times a day (00.00h, 06.00h, 12.00h,
 and 18.00h). Since moose are mostly active during dusk and dawn and
 females with calves move small distances during this period of the year
 (Neumann <em>et al.,</em> 2012), we deemed four samples a day
 sufficient to capture female positions during both resting and active
 times to describe their major habitat selection. Moose are long-lived,
 mostly solitary-living, capital breeders with a life span of more than 20
 years (Ericsson & Wallin, 2001). Females usually calve every year
 but their fertility decreases after the age of 15 years (Niedzialkowska
 <em>et al.,</em> 2022). In our study, female age averaged 8.3
 years (range 4-16 years) at their time of capture as indicated by their
 tooth wear (Ericsson & Wallin, 2001). All personnel handling the
 moose were certified according to the standards of the Swedish Animal
 Welfare Agency and the Swedish Board of Agriculture. The marking of moose
 has been approved by the Animal Care Committee in Umeå, Sweden (DNR
 A116-09, A12-12, A50-12, A205-12, A14-15, A3-16, A28-17,
 A11-2020). For each female, we linked movement data to
 her age and reproductive success in a given year (i.e. calf survival, calf
 loss due to predation or an unknown cause), resulting in a dataset
 including the calving date, the number of calves born, their summer
 survival, and the movement and age of the female. To
 study the effect of the female experience on her selection for habitat
 structures at the calving site during the first four weeks following
 parturition in a given year, we built step selection functions using five
 random steps for each observed step. We extracted habitat features at the
 end of the step to test for the selection of a given habitat feature (R
 package ‘amt’, Signer <em>et al.</em>, 2019).
 To test for site fidelity of female moose in relation to the bear
 presence and females’ experience over the years, we modeled the observed
 inter-annual distances between calving site locations in successive years
 calculated as Euclidean distances (km) separately for each female. For
 each female, we calculated this distance as the distance between the daily
 average GPS collar locations in successive years, for each day, starting
 from the birth date (day 0) through the end of the first week after
 calving (day 7). This allowed us to compare female selection (i.e. derived
 by the coordinates) both at the date of calving and during the first week
 among successive years.
description: # **Bear in mind! Bear presence and individual experience with calf
 survival shape the selection of calving sites in a long-lived solitary
 ungulate**
 [https://doi.org/10.5061/dryad.m0cfxpp9t](https://doi.org/10.5061/dryad.m0cfxpp9t) ## SHARING/ACCESS INFORMATION Recommended citation for this dataset: Dijkgraaf, L, Fredrik Stenbacka, Joris PGM Cromsigt, Göran Ericsson, Wiebke Neumann. (XXXX). Data from: Bear in mind! Bear presence and individual experience with calf survival shape the selection of calving sites in a long-lived solitary ungulate. Dryad Digital Repository. XXXX ## DATA & FILE OVERVIEW **DATA-SPECIFIC INFORMATION FOR:** Dijkgraaf_et_al_DataRcode_EcolEvol Missing data codes: n/a (data not missing per se, but not present in that specific dataset) ### Habitat selection 1\. Number of variables: 15 2\. Number of cases/rows: 108,858 3\. Variable List: * **anim_id1**: identifier for a given moose **(categorical)** * **yrMooseID1**: identifier for a given moose in a given year; first nine characters identify a given animal and later ones a given calving season **(categorical)** * **date**: day of position **(date)** * **birth_date**: calving day **(date)** * **week:** five levels, day of birth (birth), first-week following parturition (week1), second-week following parturition (week2), third-week following parturition (week3), fourth-week following parturition (week4) **(continuous)** * **case_:** two levels, observed step (TRUE), random steps (FALSE) **(categorical)** * **step_id2:** identifier for a group of movement steps, grouping an observed step with its associated five random steps **(categorical)** * **cover_low_end2:** percentage cover of vegetation up to 5 m height at the end of the movement step, proxy for shrub cover, scaled **(continuous)** * **cover_high_end2:** percentage cover of vegetation more than 5 m height at the end of the movement step, proxy for tree cover, scaled **(continuous)** * **tri_end2:** terrain ruggedness index as an indication of how hilly and uneven the terrain is at a given place, scaled **(continuous)** * **road2**: Euclidean distance from the given animal location to the nearest road in meters, scaled **(continuous)** * **group_before**: three levels; female experience with calf survival the previous calving season (alive (calves survived the calving season), Other/unknown (calf loss due to unknown reasons or other than predation), predation (calves lost due to bear predation) **(categorical)** * **study_area1:** six levels, sites 1-6, see Figure 1 * **bear_density**: two levels, animals ranging at study sites with bears and animals ranging at the study site without bears **(categorical)** * **DOP:** Dilution of precision as an index for position’s quality **(continuous)** ### **Site fidelity** 1\. Number of variables: 10 2\. Number of cases/rows: 3,989 3\. Variable List: * **yrMooseID1**: identifier for a given moose in a given year; first nine characters identify a given animal and later ones a given calving season **(categorical)** * **jday**: Julian day of the date **(continuous)** * **anim_id1**: identifier for a given moose **(categorical)** * **year**: year **(continuous)** * **age**: female age in a given year, derived by the estimated year of birth at the marking event of a given animal **(continuous)** * **bear_density**: two levels, animals ranging at study sites with bears and animals ranging at the study site without bears **(categorical)** * **group_before**: three levels; female experience with calf survival the previous calving season (alive (calves survived the calving season), Other/unknown (calf loss due to unknown reasons or other than predation), predation (calves lost due to bear predation) **(categorical)** * **days:** number of days since parturition **(continuous)** * **distance**: Euclidean distance (km) between calving sites in following years **(continuous)** * **study_area1:** six levels, sites 1-6, see Figure 1 ### RSS Appendix 1\. Number of variables: 4 2\. Number of cases/rows: 20 3\. Variable List: * **category**: three levels; female experience with calf survival the previous calving season (alive (calves survived the calving season), Other/unknown (calf loss due to unknown reasons or other than predation), predation (calves lost due to bear predation) **(categorical)** * **habitat:** four levels, habitat features(Shrubs = shrub cover, Trees = tree cover, TRI = terrain ruggedness, Road = Euclidean distance to roads **(categorical)** * **number:** ordered number **(continuous)** * **RSS**: estimated relative selection strength for the different habitats as given by the conditional logistic mixed regression **(continuous)**