Just before winter our friend Vince replaced our decrepit dining room storm windows with a lovely bay window from another job. The people didn’t want it, so their toss was our gain. That window has opened a more panoramic vista on our side yard. In recent weeks the critters most prominent in the view have been squirrels and crows.
With no basis or purpose really, I started comparing these two dooryard familiars. They are about the same length (16-21 in) and weight (12-21 oz), but there the resemblance ends. Obviously one is a mammal and the other is a bird. What seemed interesting and comparable were their social lives. Crows and squirrels are always interacting, but never the one with the other, only squirrels with squirrels and crows with crows.
Squirrels chase each other a lot, up and down trees and tree to tree, across the ground and across roofs and along the tightropes of electric and telephone lines. A lot of this chasing has to do with mating and territorial rivalry. Squirrels never seem to tussle over food per se. Crows are different. They are rather polite and discreet sexually but will steal food from each other. They will also share food willingly. These behavioral snippets are better understood in the context of the family lives of these common species.
Both squirrels and crows start shacking up in late winter and early spring. They both build nests in trees, but squirrels also like tree hollows and buildings. If you’ve had them in your attic you’ve heard them scurry and scrape and scratch and scrap, all that endless energy. You may also have heard their various vocalizations, evocative sometimes, even orgiastic.
Probably most people reading this have seen that video that challenges squirrels with elaborate obstacle courses of diabolical devices to keep them from getting at food. It’s amazing how persistent, clever and resourceful these rodents are. Just for the information a squirrel’s wild diet consists mostly of nuts, acorns, berries, and flowers. They also eat bark, eggs, sometimes even baby birds. Oh yes, this time of year also tree sap, especially maple, which squirrels get by eating twigs and buds.
An interesting difference between crows and squirrels is that though both form families, squirrels go no further than simple pair bonds typically lasting one breeding season, with the kids splitting as soon as they can be on their own. Crows, though, have extended families, with grown children helping to raise the next year’s brood, and subsequent generations up to six years. Female crows may not breed until their second or third year, gaining experience for their own future parenting.
Strong family ties, extended social bonds and genuine culture tend to be most highly developed in animal species with long individual lifespans. Surprisingly then, crows are not especially long-lived, as are their raven relatives, who may occasionally attain the century mark. Very few animals live many decades — elephants, whales, humans, ravens (scientists have wondered about the larger dinosaurs).
The average squirrel lives about as long as the average crow, about 5 or 6 years. High mortality among the young brings down average longevity in many species, so the good, full life of a lucky individual may be a better measure. A long life for a crow would be about 10 years, but one lived in captivity for just shy of 30. Ten is about the limit for a squirrel, too, but a pet squirrel is said to have attained the ripe age of 15, and a zoo captive made it to 20, the world record.
So is there more wisdom of the elders among crows than among squirrels? It does seem so. The big black birds have long memories, researchers have discovered. There is a nature documentary that shows urban crows that recognize individual people who crossed them many years before. The crows stalk their nemeses and scold them mercilessly. It’s almost unbelievable how these birds can hold a grudge. More significantly, groups of crows share information and form social networks for mutual benefit, calling friends to feast when they find good pickings, and communicating through a language of long-range cries and caws, close-range squawks and shrieks, and intimate chuckles and mutterings. Crow culture rules the roost.
Squirrels are more like gossipy, feuding neighbors engaged in lowbrow conversation across back fences. There’s a lot of chirping and chupping and squeaking and moaning and groaning, but it’s mostly talk, the only action called forth being that interminable chasing. Fast moves serve squirrels well, no doubt about that. Though a squirrel’s first instinct is to stop still, it almost immediately bolts, often to a tree, where it hides behind the trunk, or scurries up to a safer height to scan all around. If you’ve ever seen a squirrel shoot across the road in front of your car and under the car or truck in front of you, you’ve seen those amazing fast turns to dodge the moving wheels one by one at breakneck speed. Almost every time, it works! All those squished squirrels testify to times it doesn’t work, but squirrels are abundant. The visible carnage doesn’t make a dent in their overall numbers.
Is it scientific or fair to compare crows and squirrels? It probably reveals more about us than it does about them. Maybe though, this exercise does point to a truth about leisure time when it becomes fortuitously available to a species or population of animals having attained a certain threshold of braininess. The idle brain may not be so much the devil’s playground, but rather the individual’s, and the species’. ++