We tend to think of animals as “set in their ways”, following the pattern of their species and not varying in their behaviour or ecology on an individual basis. In fact, every species is made up of individuals. And once you start to think about it, of course this is the case.
People are often surprised to hear of diet variation, when wild animals feed upon substances that seem to go against their “pattern”. Crocodiles and Alligators will consume fruit, and could even act as seed dispersal agents (Grigg and Kirshner, 2015). White-tailed deer will eat nestling birds if they happen upon them. Chickadees will feed on dead mammals.
A recent observation reported in The Canadian Field Naturalist journal represents another of these striking behaviours that stands out because it is atypical for the species as a whole. The species concerned is one that many people are very familiar with: the Eastern Grey Squirrel (Sciurus carolinensis). There are already accounts of various Squirrel species hunting and feeding on other vertebrate animals, including birds and even other Grey Squirrels (ie. Cannibalism) (Squirrels as Predators, Callahan 1993). Perhaps more surprising is the recent report of hunting an animal that is outside of its normal environment: namely, a fish. In Guelph, Ontario, a Squirrel was seen to dive from a branch headfirst into a shallow portion of a river. After being underwater for a few seconds “the squirrel swam back to the snag with a fish 3-5 cm long in its mouth” (Sutton et. al. 2020). After feeding on the fish briefly, the Squirrel moved out of view into the woods.
There is so much out there to explore, in your own backyard or neighborhood. Animals are individuals, doing individual things. They are not programmed automatons following rigid beahavioural patterns. Even an animal as familiar and commonplace as the Eastern Grey Squirrel can surprise us if we take the time to pay attention.
Callahan, J. R. Squirrels as Predators. The Great Basin Naturalist, vol. 53, no. 2, 1993, pp. 137–144.
Sutton, A. O., M. Fuirst, and K. Bill. 2020. Into the drink: observation of a novel hunting technique employed by an Eastern Grey Squirrel (Sciurus carolinensis). Canadian Field-Naturalist 134(1): 42-44.
Grigg, Gordon and Kirshner, David. Biology and Evolution of Crocodylians, 2015.