Ph.D. student: Aurélien Grange, Pinngortitaleriffik, Institute of Birds and Mammals
Granted amount: DKK 2.605.200

Project description:

Caribou is a key species structuring most terrestrial ecosystems across the Arctic. Native to West
Greenland, the species is of high cultural and subsistence value for many local communities. Yet, a
better understanding of drivers of caribou space use, movements, and population structure and
adaptation is crucial for conservation and management. In this context, I plan during my PhD to
investigate how variation in caribou physiologies, seasonal movements and genetics interact in the
Kangerlussuaq-Sisimiut (KS) management area, the largest herd/area in Greenland, spanning a climatic
gradient from the coast to the inland ice.

This continentality gradient is strongly shaping vegetation communities, with direct effect on caribou
body condition and metabolism. My first objective is to investigate the different physiological
strategies caribou use to support pregnancy, within a single management region. To demonstrate the
presence of different ‘types’ of caribou, I will combine morphological measurements, diet composition,
and stable blood isotopes , providing insights into how energy is reallocated to reproduction.

Second, I will examine how vegetation, human activities, and terrain features influence caribou
movements, using GPS data from collared female caribou. I aim to test if the different ‘types’ of caribou
exhibit different movement patterns. These analyses will provide critical insights into landscape
friction, a key factor for understanding connectivity and caribou gene flow.

Third, I aim to investigate caribou population structure at fine-scale spatial scale within the KS region.
For the first time, I will integrate movement and genetic data to infer the functional connectivity of the
landscape. By analysing caribou genomic data, I aim to identify candidate genes underlying
physiological differences. Finding such genes would provide evidence of local adaptation within a same
management unit; if not it would imply that West Greenland caribou can be highly plastic and adjust
their metabolism to different environmental conditions.

The results from my PhD will have major implications for management in Greenland and other Arctic
countries, as both climate change and hunting can differently affect these caribou ‘types’. This work is
particularly relevant for the UNESCO world heritage Aasivissuit-Nipisat expanding its area across the
studies continentality gradient, with primary goals of protecting nature to sustain traditional activities
in a region facing increasing climate warming and anthropic pressures.

To remain close to my study region and its communities, I plan to spend one month per year as intern
at Qeqqata Kommunia working on initiatives work related to the UNESCO world heritage. This
experience will give me a unique opportunity to refine my hypothesis and identify the landscape
variables most likely to influence caribou physiology, movement and genetics.