Ecology on the move

Last Monday, Prof Evelyn Merril presented her research in our weekly Zoology Seminar. Evelyn is a faculty member at the University of Alberta, and has recently arrived in Oxford to work at our Department for a few weeks within the context of a mini-sabbatical. In her on words, she is “looking forward to collaborating with faculty, early career researchers, and students at Zoology, and to developing exciting ideas that will propel my research group into the next few years”.

Evelyn´s seminar, entitled “Animal movements in heterogeneous landscapes: wapiti, wolves, and prions”, took the attendees through three different study systems that her research group has examined over the last decade, all of them with the concept of movement as a common denominator. Here, I highlight some of these systems: elk and wolves.

Humans have a multitude of drastic effects on our biodiversity, but some are more direct and obvious than others. We affect species’ niches and distributions by altering global patterns of atmospheric circulation, creating pollution, worsening global warming, or carrying out activities such as deforestation. The human footprint also has a significant effect on the way that animals move; not just because we have increased the probability of accidental introductions of alien species into new habitats, but also because we inadvertently alter and limit the movement of the local fauna through the construction of our own infrastructure.

Evelyn highlighted how Alberta’s “open for business” attitude has resulted in some interesting ecological challenges. Alberta has historically welcomed various businesses for the exploitation of its natural resources. The development of a road system to get to those remote resources, often located in the middle of Canada's magnificent wilderness, continues to be a hotly debated topic: how much and where should the network be based?

Some of the research in Merrill’s research group has documented how this road system creates elk roadkill. Her research has shown that the effects are most drastic when the roads are placed along clear-cut habitats, rather than when they go through conifer forests. This finding is important as forestry operations prefer roads to go through clear cut habitats, whereas other industries show no preference for the location of the road. Evelyn's research is now showing the predicatbility of the different preferences and pressures of different enterprises, and this science is being translated into action as GIS experts are collaborating with local government to develop road systems that impact minimally on local fauna.

Evelyn’s research group also investigate how the development of roads and naturally occurring networks, such as seismic lines, may affect wolf populations. She has developed a spatially explicit model where she can examine which features of the landscape significantly affect the “time to kill” (i.e. duration between two prey consecutive prey events). She found that, contrary to her initial hypothesis, prey density did not matter much, but that a leading explanatory variable was how rugged the landscape under examination was. Her research also showed that wolves tend to use seismic lines as corridors to quickly move between different points of the landscape. The implications of this finding are vast – with more roads on the landscape, wolves may also be able to more efficiently bring down their time to kill, thus affecting the population dynamics and densities of their prey. She showed that the effects of seismic lines are most drastic where prey densities are already low. This finding is particularly important in the light of the minimal population size (effective population size) that allows for a population to persist.

Evelyn awoke a lot of interest following her seminar, and many of us from the Department followed to the University Club to continue discussions with her on her research and potential collaborations.