DOI: 10.5061/dryad.z8w9ghx8g
title: Data from: Large scale variation in birth timing and synchrony of a large herbivore along the latitudinal and altitudinal gradients

description: 1. Hopkins’ Bioclimatic Law predicts geographic patterns in phenological
 timing by establishing a correspondence between latitudinal and
 altitudinal gradients. First proposed for key phenological events of
 plants, such as leaf sprouting or flowering dates, this law has rarely
 been used to assess the geographical equivalence of key life history
 traits of mammals. 2. We hypothesize that (H1) parturition dates of
 European roe deer (Capreolus capreolus) are delayed and more synchronized
 at higher latitudes and altitudes, (H2) parturition timing varies along
 latitudinal and altitudinal gradients in a way that matches the Hopkins’
 Bioclimatic Law, and (H3) females adjust parturition timing to match the
 period of high energy demand with peak resource availability. 3. We used
 parturition dates of 7,444 European roe deer from Switzerland to assess
 altitudinal variation in birth timing and synchrony from 288 to 2,366 m
 a.s.l. We then performed a literature survey to compare altitudinal
 results with those from different populations along the species’
 latitudinal range of distribution. Finally, we performed spatial analysis
 combining our highly resolved altitudinal data on parturition dates with
 plant phenology data. 4. As expected, parturition dates were delayed with
 increasing latitude and altitude. This delay matched the Bioclimatic Law,
 as the effect of 1º increase in latitude was similar to 120 m increase in
 altitude. However, while parturitions were more synchronized with
 increasing altitude, we did not detect any trend along the latitudinal
 gradient. Finally, plant phenology explained altitudinal variation in
 parturition timing better than a linear effect of altitude. 5. Our
 findings clearly demonstrate the ability of a large herbivore to match
 parturition timing with phenological conditions across the altitudinal
 gradient, even at the smallest spatial scales. 
description: The species data were provided by courtesy of the Federal Office
 for the Environment. <b>Marta Pelaez.
 </b>Author of code, analysis and literature review.<br>
 Departamento de Sistemas y Recursos Naturales, Universidad Politecnica de
 Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain<br>
 <b>Jean-Michel Gaillard.</b> Author of analysis and literature
 review.<br> Université de Lyon, F-69000, Lyon, Université Lyon 1,
 CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, F-69622,
 Villeurbanne, France<br> <b>Kurt Bollmann.</b> Author of
 species and environment data and provided input for the
 analysis.<br> Swiss Federal Institute for Forest, Snow and Landscape
 Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland<br>
 <b>Marco Heurich.</b> Author of literature review and provided
 input for the analysis.<br> Wildlife Ecology and Wildlife
 Management, University of Freiburg, Tennenbacher Straße 4, 79106 Freiburg,
 Germany<br> Bavarian Forest National Park, Department of Visitor
 Management and National Park Monitoring, Freyunger Str. 2, 94481 Grafenau,
 Germany <b>Maik Rehnus.</b> Author of
 species and environment data, provided input for the analysis and
 corresponding author. Email: maik.rehnus@wsl.ch.<br> Swiss
 Federal Institute for Forest, Snow and Landscape Research WSL,
 Zürcherstrasse 111, 8903 Birmensdorf, Switzerland