Kanawha State Forest program shows that prolific bird's intelligence is something to crow about
LOUDENDALE, W.Va. -- Like many American households, the typical American crow family consists of a mom and a dad and several kids born in previous years that stick around for years helping to raise their younger siblings and build the family nest before literally leaving the nest themselves to mate and breed.
An American crow family unit can include a dozen or more individuals, ranging from clumsy, newly hatched juveniles and their young adult brothers and sisters to mated-for-life parents and an occasional brother or nephew of the mom or dad. Crows have also been known to adopt the offspring of unrelated neighbors.
While crows are common across all of West Virginia and most of the United States, "it is no ordinary bird," according to Kanawha State Forest naturalist Sara Miller.
Miller and Lynn Hartman, a graduate of the state Division of Natural Resources' Master Naturalist program, led a "Bird of the Month" program featuring the American crow at Kanawha State Forest last weekend. The kid-friendly event drew more than 30 attendees.
What makes crows extraordinary? For one thing, they are known to use tools to forage for food. Crows have been observed using beak-held sticks to retrieve insects from holes in trees and wooden fence rails that couldn't be reached otherwise. They have also been seen chewing on such sticks to make them fit into the holes better to improve their odds at reaching snacks of sought-after bugs.
Studies have shown that crows can identify individual human faces and remember for years those who have captured and banded them, or conversely, those who have given them regular handouts of food.
Crows have been seen working together to open garbage containers to provide a group banquet, and at this time of year, joining with other family groups to form huge flocks - sometimes involving hundreds of thousands of birds -- that gather nightly at winter roosts.
"In the winter, they gather together mainly for protection," Miller said. "If predators like owls or hawks come near, crows can swarm and harass them, and drive them off."
The "selfish herd" theory may also be at work, when it comes to huge flocks of crows at a winter roost, she said.
"This means that in a large group, those on the interior are going to be more protected than those on the outside of the group," Miller said. "This offers increased protection in numbers, like the emperor penguins in Antarctica, who huddle in large groups against the winter chill and kind of rotate - those on the outside move in where it's warmer and those on the inside are pushed outward."
Wintering in a large flock makes it possible for crows to follow each other to new sources of food, Hartman said.
Crows aren't picky when it comes to dining.
"They're opportunistic feeders," Miller said, with a diet that ranges from grains, nuts, berries and fruit to roadkill, garbage, mice, fish and smaller birds. "They're also nest predators," she said, who eat the eggs and young of other birds.
"I've had a group of them follow me when I was squirrel hunting," said Kanawha State Forest Assistant Superintendent Kevin Dials, who assumed the birds were hoping he would share some of the squirrels he had bagged.
A number of clues can be used to differentiate crows from their raven cousins.
Crows have fan-shaped tails, as opposed to the ravens' wedge-shaped tails. Ravens, which are nearly twice as large as crows, and make a croaking, "gronk-gronk" vocalization, compared to the crows' higher-pitched "caw-caw." Crows are more social than ravens, often traveling alone or in very small groups. In West Virginia, ravens generally favor feeding and nesting at elevations higher than those where crows tend to live.
According to the Cornell Lab of Ornithology, the oldest known wild crow was 16 years old, while a crow kept in captivity in New York died at the age of 59.
In November, Miller and Hartman plan to present a "Bird of the Month" program at Kanawha State Forest featuring the wild turkey.
Reach Rick Steelhammer at firstname.lastname@example.org or 304-348-5169.