DOI: 10.5061/dryad.w9ghx3fz6
title: Data from: Climate drives body mass changes in a mountain ungulate: Shorter winters lead to heavier Alpine ibex

description: Climate affects seasonality and plant phenology, which can influence
 seasonal body mass dynamics of herbivores in temperate environments. We
 investigated long-term trends of seasonal body mass changes in male Alpine
 ibex (Capra ibex). We used SEM to test direct and indirect relationships
 between body mass, mass changes and environmental and climatic variables.
 Individually recognizable Alpine ibex were weighed repeatedly between 2000
 and 2022 in Gran Paradiso National Park (Italy). Autumn mass increased
 substantially over these two decades, up to 15% in some age classes. Over
 the same time frame, both summer mass gain and winter mass loss decreased,
 suggesting that heavier autumn body mass was due to the cumulative effects
 of reduced mass loss over several winters. The environmental factor with
 the strongest effects on winter mass changes was the starting date of
 vegetation green-up at low altitude, where ibex gather after winter to
 feed on new growth vegetation. Early springs led to lower winter mass
 loss, likely because ibex relied on stored fat for a shorter period and
 had greater access to forage. High population density also increased
 winter mass loss. Environmental conditions and resource availability,
 possibly also influenced by density in winter and early spring seem
 therefore to directly affect the body mass dynamics of male Alpine ibex,
 while the effect of summer conditions appears less relevant. By affecting
 seasonal body mass dynamics, climate change may have consequences for life
 history and population dynamics of mountain herbivores, for example via
 earlier access of young males to reproduction.
description: # Climate drives body mass changes in a mountain ungulate: shorter winters
 lead to heavier Alpine ibex
 [https://doi.org/10.5061/dryad.w9ghx3fz6](https://doi.org/10.5061/dryad.w9ghx3fz6) The files include two datasets with repeated body mass data of male Alpine ibex (Capra ibex) collected in Gran Paradiso National Park between 2000 and 2022 and environmental and phenological data collected in the same area during the same period and the R code used for the analysis. ## Description of the data and file structure * Data file: 20240505_body mass_data.csv. Raw body mass data, year, date and day of the body mass measure and individual information (birth year and age at measure). Abbreviations as follows: year_weight: year of the measure (calendar year) data_weight: data of the measure (YYYY-MM-DD) day_weight: day of the measure (starting from 1st May) animal_code: identity of the individual weight: body mass (kg) year_birth: cohort of the animal (calendar year) age: age (in years) * Data file: 20240505_env var_dataset.csv. Seasonal environmental measures from 1962 to 2022. Meteorological data are available from 1962 to 2022, phenological data are available from 2000 to 2022. Years with missing data are indicated with NA. Abbreviations as follows: year: calendar year of measure WintSnow: winter (y-1) snow depth (cm) SummTmax: summer temperature (°C) SummPrec: summer precipitations (cm) SpringTmax: spring temperature (°C) SpringPrec: spring precipitations (cm) bgs: onset of spring at high altitude (doy) dmax: day of maximum NDVI at high altitude (doy) ndvi_max: maximum NDVI value at high altitude bgs_la: onset of spring at low altitude (doy) dmax_la: day of maximum NDVI at low altitude (doy) ndvi_max_la: maximum NDVI value at low altitude l_seas: length of gren-up (days) ibex_lev: ibex density ibex_lev_yb: ibex density (y-1)   ## Code/Software Analysis were run in R (R version 4.2.1 (2022-06-23 ucrt). All the code used for the analysis presented in the paper as well as the loaded packages are provided in the file: 20240625_ibex_body mass_code.R