(PART 1) Ecology and Conservation of Ungulate Migration: Lessons from Wyoming
Jerod A. Merkle, Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology, University of Wyoming
Ungulate migration has fascinated humans for centuries. The journeys these animals undertake allow large populations to prosper even when at certain times of the year their seasonal ranges can be inhospitable. Migrating ungulates require vast landscapes, and in many cases individuals must cross numerous fences and roads, and navigate rapidly changing, multiple-use lands. Migration is thus inherently difficult to manage and conserve. Moreover, recent research is changing how we view and understand migration. Where corridors were once viewed as a simple link between two disparate seasonal ranges, it is becoming clear that these corridors themselves are critical habitat. Indeed, recent studies indicate that the timing of migratory movements along corridors during spring is a key determinant of the fitness benefits (i.e., fat gain) of migration. In this presentation, I draw upon research conducted in Wyoming and elsewhere to describe: i) the behavioral processes used by ungulates to make these awe-inspiring journeys, and ii) the foraging benefits of migration. I then describe new tools to identify and conserve corridors across multiple-use landscapes. Specifically, I outline how to i) categorize and map migration corridors so they are useful to managers, ii) prioritize conservation efforts within migration corridors, and iii) integrate migration corridors into state-level policy. I conclude with a description of some successful on-the-ground conservation projects sportsmen, government agencies, and non-governmental organizations are developing to sustain migration corridors in Wyoming.
(PART 2) Movement, Migration and Ecological Plasticity in Deer Species: Facts and Consequences in a Changing European Landscape
Francesca Cagnacci*, Department of Biodiversity and Molecular Ecology – Research and Innovation Centre, Fondazione Edmund Mach; Wibke Peters, Abteilung Biodiversität, Naturschutz, Jagd, Bayerische, Landesanstalt für Wald und Forstwirtschaft (LWF); Mark Hebblewhite, Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, University of Montana and The EURODEER consortium: euroungulates.org
Migration is an important component of ungulate behavioural tactics that is tightly linked both to population distribution and to the function ungulates exert in ecosystems. The migration rate of several species has been observed to decrease, and climate change and anthropic pressure have been indicated as potential driving causes [1].
The loss of migratory behaviour in ungulates could have paramount consequences on the ecosystems that encompass their seasonal ranges, on the one side, and affect population dynamics on the other. This talk has two main goals: first, to re-establish the link between deer migratory behaviour and emerging movement patterns, reviewing the contributions to the newly established ‘migratoriness’ concept [2,3,4]; then, to assess the determinants of migration by looking at multi-population movement datasets of deer species in temperate climates, specifically the European roe deer Capreolus capreolus [5] and red deer Cervus elaphus.
The analysis of movement trajectories of deer species through different methods allowed us to identify inconsistencies in the classification of migratory behaviour at individual level that we attributed to individual plasticity. We thus acknowledged the emergence of movement patterns other than residence and stereotyped migration through the concept of ‘migratoriness’, measured through several newly proposed metrics.
By analysing movement data from the Eurodeer consortium (individual trajectories of roe and red deer from more than 10 populations for this study), we assessed the effects of intrinsic factors (sex) and extrinsic conditions (e.g. topography, seasonality, canopy closure, plant productivity/NDVI, snow layer) on seasonal distribution of individuals and parameters describing migration plasticity. Although variation in plant phenology affected migration probability in both species, we found a stronger disconnect between plant productivity and migration for roe deer than for red deer, especially in spring. In a fine-scale analysis at the local scale, we also observed a strong relation between the snow layer (i.e., snow depth) and the winter distribution of roe deer, in presence of supplemental feeding. Our results suggest that climatic and landscape changes may affect future deer species migrations and seasonal distribution of populations.
We conclude with considerations on how these changes may feedback on deer habitat productivity, biodiversity, and ecosystem services, and if they should be considered as a form of reversible adaptive behavior.
