Guest post by Chloé Nater
Size‐ and stage‐dependence in cause‐specific mortality of migratory brown trout (2020) Nater at al., Journal of Animal Ecology, https://doi.org/10.1111/1365-2656.13269
When it comes to dying, not everyone is equal.
The corona-virus pandemic has reminded us of that over the last months: the same disease that passes often without any symptoms in young children is life-threatening for the elderly. Age, in this case, seems to influence how likely someone is to die from the disease. For other risks of death – take, for example, car accidents – age is not that important, but location may be: the chance of dying in a car accident is higher for someone who spends two hours per day commuting by car on a busy highway, than for someone who only needs to walk across one car-free road to get to work.
For animals, this is very much the same. They can die from a variety of causes (starving, predation, disease, hunting, etc.), and an individual animal’s risks of dying from any of these depend on characteristics like age, size, or colour, and on location. How many and which animals die from different causes then has consequences for the size of populations, and sometimes also for other species in the area, including humans.