DOI: 10.5061/dryad.mm324rv
title: Data from: Accelerating across the landscape: the energetic costs of natal dispersal in a large herbivore

description: 1. Dispersal is a key mechanism enabling species to adjust their
 geographic range to rapid global change. However, dispersal is costly and
 environmental modifications are likely to modify the cost-benefit balance
 of individual dispersal decisions, for example, by decreasing functional
 connectivity. 2. Dispersal costs occur during departure, transience and
 settlement, and are levied in terms of energy, risk, time and lost
 opportunity, potentially influencing individual fitness. However, to the
 best of our knowledge, no study has yet quantified the energetic costs of
 dispersal across the dispersal period by comparing dispersing and
 philopatric individuals in the wild.3. Here, we employed animal-born
 bio-loggers on a relatively large sample (N = 105) of juvenile roe deer to
 estimate energy expenditure indexed using the vector of dynamic body
 acceleration (VeDBA) and mobility (distance travelled) in an intensively
 monitored population in the south west of France. We predicted that energy
 expenditure would be higher in dispersers compared to philopatric
 individuals. We expected costs to be i/ particularly high during
 transience, ii/ especially high in the more fragmented areas of the
 landscape, and iii/ concentrated during the night to avoid disturbance
 caused by human activity. 4. There were no differences in energy
 expenditure between dispersers and philopatric individuals during the
 pre-dispersal phase. However, dispersers expended around 22% more energy
 and travelled around 63% further per day than philopatric individuals
 during transience. Differences in energy expenditure were much less
 pronounced during the settlement phase. The costs of transience were
 almost uniquely confined to the dawn period, when dispersers spent 23%
 more energy and travelled 112% further than philopatric individuals.
 Finally, the energetic costs of transience per unit time and the total
 distance travelled to locate a suitable settlement range were higher in
 areas of high road density. 5. Our results provide strong support for the
 hypothesis that natal dispersal is energetically costly and indicate that
 transience is the most costly part of the process, particularly in
 fragmented landscapes. Further work is required to link dispersal costs
 with fitness components so as to understand the likely outcome of further
 environmental modifications on the evolution of dispersal behaviour.
description: Data for the relation
 between activity and accelerometryThis file contains daily
 VeDBAactivity data and daily VeDBAaccelerometry data, collected in the
 field for the first analysis “VeDBAactivity as an index of energy
 expenditure”. Columns: 1: individual identity/ 2: daily VeDBA activity
 values/ 3: daily VeDBA accelerometry values.Daily_activity_daily_accelerometry_data_Analysis1.csvData for the variation of daily activity during dispersal phasesThis file contains daily VeDBA activity data, collected in the field for the second analysis “Daily energy expenditure of dispersing vs. philopatric individuals”. Columns: 1: individual identity/ 2: daily VeDBA activity values/ 3: sex of individuals (M for male and F for female)/ 4: dispersal status of individuals (D for dispersers and P for philopatric individuals)/ 5: dispersal phase (pre_disp for Pre-dispersal, disp for Transience and post_disp for Post-dispersal)/ 6: year.Daily_activity_data_Analysis2.csvData for the variation of daily mobility during dispersal phasesThis file contains daily mobility data, collected in the field for the third analysis “Daily mobility of dispersing vs. philopatric individuals”. Columns: 1: individual identity/ 2: daily mobility values/ 3: sex of individuals (M for male and F for female)/ 4: dispersal status of individuals (D for dispersers and P for philopatric individuals)/ 5: days around the median date of transience/ 6: year.Daily_mobility_data_Analysis3.csvData for the variation of the circadian rhythm of activity during dispersal phasesThe circadian rhythm of dispersal and of its energetic costs”. Columns: 1: individual identity/ 2: hourly activity values/ 3: sex of individuals (M for male and F for female)/ 4: dispersal status of individuals (D for dispersers and P for philopatric individuals)/ 5: dispersal phase (pre_disp for Pre-dispersal, disp for Transience and post_disp for Post-dispersal)/ 6: hour of the day/ 7: yearHourly_activity_data_Analysis4.csvData for the variation of the circadian rhythm of mobility during dispersal phasesThis file contains hourly mobility data, collected in the field for the fourth analysis “The circadian rhythm of dispersal and of its energetic costs”. Columns: 1: individual identity/ 2: hourly mobility values/ 3: sex of individuals (M for male and F for female)/ 4: dispersal status of individuals (D for dispersers and P for philopatric individuals)/ 5: dispersal phase (pre_disp for Pre-dispersal, disp for Transience and post_disp for Post-dispersal)/ 6: hour of the day/ 7: year.Hourly_mobility_data_Analysis4.csvData for the variation of daily activity during the transience according landscape fragmentationThis file contains daily VeDBA activity data of dispersers during the transience phase, collected in the field for the fifth analysis “The influence of landscape fragmentation on the energetic costs of dispersal transience”. Columns: 1: individual identity/ 2: daily VeDBA activity values during the transience/ 3: sex of individuals (M for male and F for female)/ 4: proportion of roads in the landscape/ 5: proportion of buildings in the landscape/ 6: proportion of woodland in the landscape/ 7: year.Daily_activity_transience_data_Analysis5.csvData for the variation of total distance of dispersal during the transience according landscape fragmentationThis file contains total dispersal distance data of dispersers during the transience phase, collected in the field for the fifth analysis “The influence of landscape fragmentation on the energetic costs of dispersal transience”. Columns: 1: individual identity / 2: total dispersal distance values/ 3: sex of individuals (M for male and F for female)/ 4: proportion of roads in the landscape/ 5: proportion of buildings in the landscape/ 6: proportion of woodland in the landscape/ 7: year.Dispersal_distance_transience_data_Analysis5.csv