Habitat selection in four whale species of the St-Lawrence Gulf
- Key words: Habitat use, Habitat selection, Gulf of Saint-Lawrence, Rorqual whales,
- Species studied: Blue whale, Finback whale, Humpback whale, Minke whale
- Field site: Mingan Islands
- Time period: 2002-2007
Collaborator
- Richard Sears, Mingan Island Cetacean Study (MICS)
The Estuary and Gulf of St. Lawrence constitute a highly productive system with the richest krill aggregation documented in the northwest Atlantic. This attracts a dozen cetacean species during the summer and fall. These whales are faced with several environmental threats, such as toxic pollutants, collision with boats and entanglement in fishing gear. We study a variety of environmental factors that are likely to influence the fine-scale mechanisms of habitat selection in blue, finback, humpback and minke whales. The Mingan Island Cetacean Study (MICS) has carried out field studies in the Gulf of St. Lawrence and accumulated considerable data over the last 25 years. The project is based on the analysis of this dataset. Identifying and predicting areas of greater ecological importance can help mitigate the overlap between these areas and human activities such as shipping lanes, whale-watching, fishing.
The arctic expedition "Tundra Northwest 1999"
- Key words: Tundra ecology, ship based research expedition, international project, trophic interactions, mammalian herbivores
- Species studied: Most mammalian herbivores of the arctic tundra, with emphasis on Collared lemmings (Dicrostonys groenlandicus), Barren-Ground Caribou (Rangifer tarandus), and Muskoxen (Ovibos moschatus)
- Field sites: 17 sites distributed across Nunavut, Northwest Territories, and the Yukon (Canada)
- Time period: 1999
Main collaborators:
- Dr. Jep Agrell, Lund University, Sweden
- Dr. Anders Angerbjörn, Stockholm University, Sweden
- Dr. Kjell Danell, Swedish University of Agricultural Sciences, Umeå, Sweden
- Dr. Charles J. Krebs, University of British Columbia, Canada
Research funding :
- Swedish Polar Research Secretariat
- Canadian Department of Fisheries and Oceans/Canadian Coast Guard
- Swedish Research Council (Grant to J Agrell)
- Canadian Circumpolar Institute (Grant to D Berteaux)
Tundra Northwest 1999 was a ship based research expedition to the Canadian arctic archipelago. The icebreaker "Louis St-Laurent" has been used as a mobile base from which we have been put ashore by helicopters and boats at some 17 study sites. We have collected data and samples along two gradients:
(1) In a south-north direction, from Low Arctic cottongrass tundra to High Arctic semi-desert, with a marked decrease in temperature towards the north.
(2) Along an east-west gradient from Baffin Island to the Yukon-Alaska border, crossing an important biogeographic boundary (the Mackenzie River outlet).
This expedition represented a new concept in terrestrial ecology. It provided us with a unique opportunity to study the dynamics and variation of tundra ecosystems over a large area during one growing season. I focused on the herbivores (lemmings, caribou, muskoxen, hares, geese, ptarmigarn) and their role in the tundra ecosystem. Knowledge about the interactions between plants, herbivores, and predators is necessary for our understanding of arctic biodiversity, the impact of global changes on arctic natural communities, and for management programs in the Arctic. This project is now at the analysis and publication stage.
Experimental study of food selection by white-tailed deer
- Key words: Food choice, energy and protein, emergency feeding, deer yard, winter
- Species studied: White-tailed deer (Odocoileus virginianus)
- Field site: Pohénégamook (Québec, Canada)
- Time period: 1996
Main collaborators:
- Dr. Michel Crête, Ministère Faune et Parcs, Québec, Canada
- Dr. Jean-Pierre Ouellet, Université du Québec à Rimouski, Québec, Canada
- Mr. Jean Maltais, Université Laval, Québec, Canada
- Dr. Jean Huot, Université Laval, Québec, Canada
Research funding :
- Natural Sciences and Engineering Council of Canada
- Fonds pour la Formation de Chercheurs et l'Aide à la Recherche du Québec
- Ministère de l'Environnement et de la Faune du Québec
- Ministère des Resources Naturelles du Québec
- Conseil Régional de Concertation et de Développement du Bas-Saint-Laurent
- Fondation de la Faune du Québec
- Fédération Québécoise de la Faune
White-tailed deer is an important game species in North America, and wildlife managers try to maintain populations at high densities. In Canada, however, harsh winters can sometimes have severe impacts on the survival of individuals, particularly when snow is abundant. Emergency feeding programs are thus developed to sustain deer populations. In the province of Québec, emergency feeding programs concentrate in the Bas-Saint-Laurent and Gaspésie regions, where winter mortalities as high as 40% have already been recorded.
I have joined in 1996 a team of researchers from Université Laval and Université du Québec à Rimouski to help with the development of an emergency feeding program at Pohénégamook (Bas-Saint-Laurent). One aim of our work was to measure the preferences of wild deer for artificial foods of varying energy and protein contents. Knowing deer preferences was critical because energy and protein are extremely important to the physiology of individuals, and giving inapropriate feeds to starving deer would have resulted in the failure of the feeding program.
In parallel with this applied objective, we also used our unique field conditions (large number of wild animals easy to observe) to answer some more general questions about the food selection process in wild herbivores. In particular, we were able for the first time to demonstrate experimentally that wild large herbivores can recognize the energy and protein contents of their food. In animal ecology as well as in other sciences, it is often the case that applied and basic research can go hand in hand if objectives are clear and work is planned carefully.
Behaviour and ecophysiology of voles living under the snow
- Key words: Energetics, winter ecology, group living, doubly labelled water, telemetry, social behavior
- Species studied: Meadow vole (Microtus pennsylvanicus)
- Field site: Sherbrooke (Québec, Canada)
- Time period: 1992-1995
Main collaborators:
- Dr. Jean-Marie Bergeron, Université de Sherbrooke, Québec, Canada
- Dr. Don Thomas, Université de Sherbrooke, Québec, Canada
Research funding :
- Natural Sciences and Engineering Council of Canada (NSERC)
- Fonds pour la Formation de Chercheurs et l'Aide à la Recherche, Québec
The reasons why animals live in groups have always fascinated animal ecologists. We now think that animals live in groups for one or more of the following four reasons: 1- It allows them to decrease predation risk; 2- It increases their foraging efficiency; 3- It allows them to share routinely some kind of important information; and 4- It is a simple consequence of resource clumping.
Many small mammals remain active during the wintertime, and form groups below the snow cover. Some have suggested that they do so primarily because of the energetic benefits incurred from nest sharing (the "huddling hypothesis"). If this was the case, then a fifth cause of group living should be recognized.
We have used the meadow vole as a model species to study group formation in winter and test the validity of the huddling hypothesis. Using a technique called "doubly labelled water", we have injected some voles with micro-quantities of tritium and oxygen-18, which allowed us to compare directly in the field the energy expenditures of animals living in groups versus alone. This sophisticated approach was used for the first time in such a context. Results clearly showed that the huddling hypothesis was NOT valid. Interestingly, it is not the first time that common ideas about the ecology of wild animals are rejected by careful measurements performed in natural conditions. This should warn us against accepting common knowledge without criticism.
Population dynamics of feral cattle on Amsterdam Island
- Key words: Island ecosystem, intoduction of exotic species, population structure, sex ratio, sex biased mortality, conservation
- Species studied: Feral Cattle (Bos taurus)
- Field site: Amsterdam Island, French Subantarctic Islands (Southern Indian Ocean)
- Time period: 1989-1991
Main collaborators:
- Dr. Pierre Jouventin, Centre National de la Recherche Scientifique, France
- Dr. Thierry Micol, Centre National de la Recherche Scientifique, France
- Dr. Claude Guintard, École Nationale Vétérinaire de Nantes, France
Research funding:
- Terres Australes et Antarctiques Françaises
- Centre National de la Recherche Scientifique (France)
Lots of exotic species have been introduced to oceanic islands in the last centuries. The tiny volcanic "Amsterdam Island", located half-way between South Africa and Australia, has been no exception to this widespread phenomenon. Cats, rats, mice, and cattle now coexist on Amsterdam Island with penguins, albatrosses, sea lions, and elephant seals. This unusual assemblage of species is far from stable, and it has become clear in the 80's that some of the most fragile plant communities of Amsterdam Island could quickly disappear due to cattle grazing and trampling. With less than 15 breeding pairs, one endemic species of albatros (the Amsterdam albatros) was even close to extinction, perhaps due to loss of nesting habitat.
A project of ecological rehabilitation of Amsterdam Island was started in 1987 by the Centre National de la Recherche Scientifique (France) and the Administration des Terres Australes et Antarctiques Françaises (France). The main objective of the project was to reduce the population of feral cattle on the most fragile parts of the island. At the same time, however, a fraction of this old cattle breed was maintained on other parts of the island to preserve its unique genetic value. I spent 14 months on Amsterdam Island to study the demography of the cattle population and to monitor populations of the native bird and mammal species. Due to the removal of more than a thousand bulls and cows, the fragile fauna and flora of Amsterdam Island now seem to slowly recover from the disastrous effects of the cattle invasion.
Relationships between porcupines and the forest
- Key words: Energetics, forest ecology, Parc du Bic, plant-herbivore interactions, porcupine
- Species studied: North-American porcupine (Erithizon dorsatum)
- Field site: Parc du Bic (shore of the St-Lawrence River, Québec, Canada)
Time period: 2000-ongoing
Mammalian herbivores are present in nearly all terrestrial ecosystems, they have major impacts on plant communities, and they are a key link in food chains. They are thus central to many problems of basic ecology, and because of their value to humans, they also are at the heart of numerous programs of conservation and wildlife management. Yet there is still a lot that we do not understand regarding the relationships between plants and herbivores.
North-American porcupines rely on a poor quality diet (tree leaves in summer and bark in winter) abd seem to face serious limits in their energy budget. This probably explains their low reproductive rate (only 1 baby per year), reduced locomotion speed, and small home ranges. Porcupines are thus interesting models to examine the energetic constraints faced by mammalian herbivores. In addition, they can have obvious impacts on the vegetation when they feed on tree bark, which also makes them excellent models to examine the effects of herbivores on their environment.
We are using a population of marked individuals in Parc du Bic (Québec) since 2000 to better understand the relationship between this folivorous mammal and the forest ecosystem.
Behavioural ecology of red squirrels in the boreal forest
- key words: Long-term study, breeding dispersal, sex ratio variations, age effects, parturition date, litter size
- Species studied: North-American red squirrel (Tamiasciurus hudsonicus)
- Field site: Kluane (Yukon, Canada)
- Time period: 1997-ongoing
Collaboration:
- Dr. Stan Boutin, University of Alberta, Edmonton, Canada
Support of the research:
- Natural Sciences and Engineering Council of Canada (Grant to S. Boutin)
- Fonds pour la Formation de Chercheurs et l'Aide à la Recherche du Québec (Fellowship to D. Berteaux)
Stan Boutin, University of Alberta, has been following a po^pulation of red squirrels in the boreal forest of Kluane (Southern Yukon) since 1987. The reproduction and survival of a large number of individuals of known life-history is now monitored every year. Because of the unique opportunities that this population offers to test basic questions in the field of animal ecology, I have joinde the project in 1997 to study:
- Breeding dispersal by adult females
- Fitness consequences of variations in parturition date and litter size
- Causes and consequences of variations in sex ratio at birth
- Age effects in the population
This work is clearly showing that the patient study of some wild aniamls throughout their entire life is one of the most powerful ways to understand the rules governing animal ecology and the evolution of life. One of the most recent discoveries in this project is that red squirrels seem to be able to cope very well with the dramatic climate changes that are occuring in the North; they have advanced their breeding dates by about 18 days over the last 3 squirrel generations, through both phenotypic plasticity and microevolution.