American crow is both interesting and intelligent
It is said that the American crow is one of the most (if not the most) intelligent wild birds.
Indeed, if white-tailed deer were as smart as crows, few collisions with motor vehicles would occur on our roadways. Crows, as most of us have come to expect, will often hop to the side of the road to allow our passing when they find themselves feeding or gathering on road surfaces.
Crows are very common and abundant Minnesota birds. Related to ravens and jays, not many birds are entirely black, as crows are. Consequently, few birds can be confused with the American crow. However, here in the northland, many people frequently confuse crows for ravens and vice versa.
The differences between crows and ravens become obvious when one learns the telltale traits of each bird. Nonetheless, confusion is inevitable given these two species' overlapping ranges and habitats, not to mention their overall similar appearance.
First of all, the physical features of crows are smaller than those of ravens. The bill of the common raven is heavier, more robust than that of the American crow. As well, a raven is a larger and heavier bird -- the wingspan of the crow is about 39 inches, the raven's about 53 inches.
What's more, their voices are much different. Typical of the crow is the hoarse "caaw," whereas the raven includes a much wider variety of vocalizations that range from croaks to bell- and twang-like notes and calls. Other physical differences include the relative shaggy appearance of the raven's throat plumage compared to the crow's sleeker-looking throat feathers.
Despite the crow's omnipresence, and perhaps even its reputation as a marauding, crop-damaging egg stealer, I can think of few other native birds more adaptable and widespread. Here's a bird that is as much at home in the deep South as it is in the far North. American crows are distributed throughout most of North America, except for Alaska and Canada's northernmost provinces.
An interesting part of crows' behavior is their sense of community with one another. It's no mystery to anyone familiar with crows that these birds tend to form large and noisy flocks. But what might not be common knowledge is how cooperative some populations or "family groups" of crows tend to be when it comes to brood-rearing.
For instance, research has shown that even though crows become reproductively mature at about 2 years of age, they don't necessarily form pair-bonds, mate and raise their own offspring immediately.
It turns out that some crows will help raise their own siblings, staying within their parents' territory for five years or longer while assisting with parental duties such as feeding nestlings and acting as sentinels.
It's believed that strategies such as these help increase nestling survival, though some research suggests that the social system does not increase brood survivorship anymore than when a pair of crows raise their offspring alone.
Still, the social system of crows is something to be admired. Crows that are related are known to preen one another, for example. Other obvious benefits of a highly developed social order are protection from predators and finding food sources.
With so many watchful crows, some of which act as sentinels, it's rare that a would-be predator such as a hawk or owl, or some mammalian predator like a pine marten or red squirrel, could get close enough to an unwary individual or a nest full of eggs or hatchlings without another crow discovering its presence first.
At such times, woe is the culprit intent on doing harm to a crow, for in these cases, the entire flock acts swiftly in attacking, swooping, vocalizing and raising complete havoc for the newly discovered intruder. Such hapless trespassers are usually mobbed and driven away by the relentless harassment of dozens of crows. Rare is the animal that can sustain the attack of a flock of crows.
While the intelligence of crows is not disputed, it is difficult to study and learn just how intelligent wild crows really are. Reports exist that crows can distinguish between a man carrying a gun and a man carrying a stick.
Such an incident is related by the late Ernest Thompson Seton, who, in his popular book "Wild Animals I Have Known," wrote about "Silverspot, the Story of a Crow."
In the story, Seton relates how Silverspot would fly above him and vocalize to his flock. To test Silverspot's intelligence, Seton, during separate times while standing on a bridge that spanned a ravine, stood alone one day, took with him a stick on another day, and stood on the bridge holding a gun on the third day.
When he held the gun, Seton wrote, "... at once (Silverspot) cried out, 'Great danger -- a gun.' 'ca-ca-ca-ca Caw!' His lieutenant repeated the cry, and every crow in the troop began to tower and scatter from the rest, till they were far above gun shot, and so passed safely over, coming down again to the shelter of the valley when well beyond reach."
Mr. Seton also wrote, "Crows know the value of organization, and are as well drilled as soldiers -- very much better than some soldiers, in fact, for crows are always on duty, always at war, and always dependent on each other for life and safety." He further stated that "'Wise as an old crow' did not become a saying without good reason."
To be sure, the American crow, a year-round rural and urban Minnesota resident, is as interesting a bird as they come as we get out and enjoy the great outdoors.
Blane Klemek is the Bemidji area assistant wildlife manager, DNR Division of Fish & Wildlife. He can be reached at email@example.com