Climate drives body mass changes in a mountain ungulate: Shorter winters lead to heavier Alpine ibex

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 lo..., , , # 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...