For small animals like the mouse, predators are a constant concern (Image Credit: Jess, CC BY-NC 2.0)
Maximising survival by shifting the daily timing of activity (2019) van der Vinne et al., Ecology Letters, https://doi.org/10.1111/ele.13404
All animals need to eat food to survive and maintain their energy balance, but unlike us they can’t just order a pizza and have the food brought to them. They must always forage for food themselves, and every time that they do they expose themselves to predators. Small mammals like mice balance this trade-off by foraging for food at night, when their risk of predation is lowest.
One interesting strategy that mice can employ is to switch their foraging from the nighttime to the day, if they cannot get enough resources during the night or if their nighttime predation risk increases. The authors of today’s paper wanted to develop a model to predict under what conditions these temporal switches would occur, a model which they then tested with mice in the field.
Deer mice like the one above are small parts of a complex and interconnected world. When two pieces of their world work against them simultaneously, how are these mice affected? (Image Credit: USDA, CC BY 2.0).
Botfly infections impair the aerobic performance and survival of montane populations of deer mice, Peromyscus maniculatus rufinus (2019) Wilde et al., Functional Ecology, https://dx.doi.org/10.1111/1365-2435.13276
Parasites are bad news for the organisms that host them. Some parasites are so bad, they can actually make the host kill itself. Despite these clear and obvious costs to infection, the common consensus is that parasites are not too big of a deal for the host, because of how rare parasitic infection is on average. For example, in my research system only one in ten animals have parasites.
But when these ill-effects of parasitism are combined with other detrimental factors, such as a harsh environment, an organism with parasites is forced to deal with not one but two stressors. The authors of today’s paper were interested in how these effects of parasites may change depending on the environment that the host lived in.