Crows – Of Mobbing and Murder

We have two species of crows in the DC area: the common American Crow (Corvus brachyrynchus) and the slightly smaller Fish Crow (Corvus ossifragus), which is usually associated with water.

crow tangled in a line

Crows are curious, and that occasionally gets them into trouble. We had to untangle this one that got tangled in a line.

The two are tough to differentiate (apart from the nasal like calls of the Fish Crow) and often flock together. Fish Crows have been expanding their range inland along waterways. American Crows are the largest of the true crows in North America at 16-20 inches, compared to the 14-16 inch Fish Crows. All crows (called corvids because they’re in the Corvidae family, the crows, ravens, magpies and jays) are considered among the smartest of birds, with good reason. American Crows are incredibly adaptable creatures with some amazing natural history allowing them to thrive.

First of all, crows will eat just about anything. While they prefer animal protein (they love worms), they will eat quite a bit of plant material as well. And they won’t be fooled by tactics such as scarecrows or fake owls to keep away, they are much too smart for that. The lengths corvids will go to get food are legendary, with some types of crows worldwide using tools, stealing fish caught ice-fishing, cracking nuts under car tires, using water to soften hard foods and more. Our own local crows are also very adept at getting food. Here is a short video of crows taking advantage of red cedar fruits.

While they love to eat meat, crow beaks are not always strong enough to make them great scavengers. But they will take advantage of road kill, letting the car tires help them to not only kill their food, but break the skin open to allow them access to the softer insides. Crows will also raid bird nests, eating both eggs and the young. This is one of the reasons you see birds gang up and mob them all the time. As they sometimes target poultry, this does not endear them to many farmers.

They will also eat young animals, though again, it isn’t easy for crows to dispatch potential prey with their beaks. It sometimes takes some great effort and time for them to finally kill their food. I’ve seen several crows all ganging up on a young rat, pecking at it, chasing and cornering it among each other until it finally died. Crows will also raid pet bowls, scavenge garbage and go after baby turtles. They will sometimes follow the edges of forest fires to catch whatever the flames force out into the open. I’ve seen them patrolling the edges of vernal pools, intercepting frogs as they make their way to the ponds to lay eggs. When they have enough food, they may cache leftovers for later use. If they eat something indigestible such as feathers, fur or bone, these get coughed up in pellets similar to owls.

 

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