Feast and Famine in the Anthropocene, from abundance to deficiencies: do seeds meet the micronutrient requirements of terrestrial wildlife?
My research is primarily focused on understanding how the deficiencies or abundance in essential micronutrients with strong potential on aging and reproduction influence life-history trade-offs of organisms. Specifically, I am interested in understanding how key vitamins and amino acids – such as vitamin B3 and its precursor the tryptophan, which are known to have strong potential in aging, immunity and reproduction in humans and domesticated animals – can modulate key functions and life-history trajectories of terrestrial wildlife.
My PhD work highlighted how deficiencies in tryptophan and vitamin B3, caused by the generalization of crop monoculture, can impair the fitness of a highly threatened vertebrate species. Investigating the nutritional effects of crops on the fitness of the European hamster (Cricetus cricetus), seeking to explain the dramatic decline of this species in Europe, I found that elevated corn consumption reduces hamsters reproduction by 95% because of a major deficiency in vitamin B3 (niacin) and its precursor, the tryptophan, causing maternal infanticides.
I am now investigating:
1) the effects of tryptophan and vitamin B3 intakes on the life-history traits of other food-hoarding hibernators (i.e. chipmunks) in a context of global change, in collaboration with Patrick Bergeron (Ubishops), Denis Réale (UQAM) and Dany Garant (Université de Sherbrooke).
2) how defficiencies in tryptophan can affect other farmland species contrained to corn monocultures (e.g. pollinators, hares...) in collaboration with Mathieu Lihoreau (CRCA) and Walter Arnold (VetMed Uni).
(c) Daphné Bourget
NEWS & UPCOMING EVENTS
I am now member of the B-Lab, working on the nutritional ecology of chipmunks!
Our research featured in the Smithsonian magazine
BBC Interview - Can we ever understand animals?
Many thanks to the SAUAS & De Dietrich association for their PhD price!
Many thanks to the Chapitre de St Thomas for rewarding my PhD work with the 2018 Special Price in Ecology
A story of girls, women and science!
Consumption of red maple in anticipation of beech mast-seeding drives reproduction in Eastern chipmunks
Understanding the determinants of reproduction is a central question in evolutionary ecology. In pulsed resources environments, the reproduction and population dynamics of seed consumers driven by pulsed production of seeds by trees, or mast-seeding. In Southern Québec, eastern chipmunks exclusively reproduce during the summer before and the spring after a mast-seeding event of American beech. They thus seem to anticipate beech mast by reproducing during early summer, so that juveniles can emerge at the time of maximum beechnut abundance during late summer.
However, the cues allowing chipmunks to anticipate beech mast remain unknown, and the existence of the anticipation process itself has been questioned. To tackle those issues, we investigated the links between the nutritional ecology and reproduction of adult chipmunks and compared their spring diet in mast- post-mast years.
We monitored female reproductive status (N=446), analyzed cheek pouch contents at capture (n=recorded seed production by deciduous trees on three different sites in Mont-Sutton from 2006 to 2018.
Results revealed a systematic shift in chipmunk diet towards red maple seeds in springs preceding a beech mast, with red maple seeds composing more than 77% of chipmunk diet. However, red maple consumption was unrelated to red maple production, but was related to beech seed production in the upcoming fall.
Our results confirm that chipmunks anticipate beech mast-seeding and highlight a key role of red maple consumption in that anticipation. Results also suggest that red maple seeds may contain nutrients or secondary-plant components essential to sustain or trigger the summer reproduction in chipmunks, which allow them to remain synchronized with pulsed productions of both red maple and beech and improve their fitness.
The common hamster Cricetus cricetus was long considered to be a pest species for crops, but its populations are now dramatically declining. The conservation of this species can only be achieved via an up‐to‐date knowledge of its ecology. However, its diet composition has never been exhaustively reviewed and the last peer‐reviewed publication on its feeding ecology in farmlands dates back to 1974.
This review of the literature aims to establish a list of plant and animal taxa consumed by common hamsters, providing knowledge to be applied to the conservation of hamsters and to identify the main avenues of future research.
Hamsters consume four main categories of food: crops, weeds, trees/shrubs and animals, including mammals, birds, herptiles and invertebrates. Vegetable foods are more diverse (114 taxa) than animal foods (11 taxa). Hamsters mainly consume animals and green parts of plants (flowers and leaves) in spring and summer, and store energy‐rich and non‐perishable foods for winter...