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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International Migratory Bird Day Festival

Cancelled due to the projected rain.

Tiny hummingbirds and fierce osprey are all migrating back from South America. As part of Neighborhood Day 2017, come learn about these and other fabulous flyers with hands-on activities, games, crafts, bird walks and more on Saturday, May 13: 9-11 a.m. at the Lacey Woods Park Picnic Shelter during Arlington?s first annual International Migratory Bird Day Festival!

For information, call 703-228-3403 or email jsoles@arlingtonva.us. No registration required.

International Migratory Bird Day Festival

Festival International Del Dia De Las Aves Migratorias 2017

Winter Birds of Arlington

In the late summer and early fall, many warblers, thrushes and other summer resident songbirds migrate to destinations as far south as South America. Left behind are Northern Cardinals, Song Sparrows, Downy Woodpeckers and many other year-round residents. They are joined for the winter by another group of migrants for whom we are the south. Here’s a look at some of the winter-resident birds you can find in Arlington:

Dark-eyed Junco

Often called snowbirds because they seem to arrive not long before the snowy weather begins. Some Dark-eyed Juncos make a vertical migration, meaning they move from mountains to lowlands as winter approaches, rather than heading south. They frequent feeders but usually feed only on seed spilled on the ground. Juncos tend to forage in a flock during the winter with the more dominant birds holding the safer middle of the group and subordinate birds on the more dangerous edges.

White-throated Sparrow

These birds nest far into northern Canada, so our relatively mild winters probably present little challenge to their survival. Another common winter bird often seen at feeders, White-throated are a fairly easy sparrow to identify, in part by their black-and-white or black-and-tan striped head and white patch on their throat. You might also catch snippets of their thin “oh sweet, Canada, Canada” song, especially later in the winter.

Ruby-crowned and Golden-crowned Kinglet

Tiny and always on the move, kinglets can be a can be difficult to see well enough to identify without binoculars. Sometimes, though, if you stand or sit quietly when they appear, you are rewarded with very close looks. Both species feed on insects, even in winter. They are adept at finding insect and spider eggs, various insect larvae and pupae, and adult insects and spiders stashed away in various hiding places. Of the two, the Golden-crowned is the most likely to reveal its crown to an observer.

Brown Creeper

Tiny and with plumage on their back that mimics tree bark, Brown Creepers can be a challenge to spot. They spiral their way up tree trunks in search of the insects and spiders that, like kinglets, get them through the winter. Their long, down-curving bill is the perfect tool for plucking these delicacies from cracks and crevices. When a Brown Creeper nears the top of one tree, it flies down to the base of another and spirals its way up again and so on through the forest.

Hermit Thrush

The Hermit Thrush replaces the melodious summer-resident Wood Thrush in our woods during the winter. They are often found on low branches or on the ground where they have a rather robin-like stance, not surprising since they are a smaller member of the same family. Unlike a robin, they have a brown back and a buffy breast with smeary spots. Hermit Thrushes also tend to slowly bob their rufous-colored tail when perched. They switch from a mostly insect diet in the summer to more of a fruit diet in fall and winter, including poison ivy berries!

Winter Wren

Winter Wrens are my favorite winter songbird, combining cute and tough into a tiny, seemingly fearless package. They spend much of their time on the ground foraging for insects and spiders and venturing into places where I’d fear to stick my hand. A short stubby tail and mostly dark brown plumage without a noticeable eye-strip distinguish Winter Wrens from our larger, year-round resident Carolina Wrens. Sometimes they’ll give a little burst song in winter and it’s hard to believe that all that sound comes out of such a tiny bird.

Yellow-bellied Sapsucker

Folks are sometimes surprised to learn that this is a real bird and not just a made-up name. Strictly speaking, a member of the woodpecker family and not a songbird, sapsuckers really do drink sap from shallow “wells” they drill into trees with their stout bills. You can tell if sapsuckers are using a tree by the rows of sap wells ringing the trunk or branches. Many other animals take advantage of this food source, such as insects, gray squirrels, flying squirrels, and early-spring arriving hummingbirds.

Winter Birding Programs

Long Branch and Gulf Branch Nature Centers are offering a variety of birding programs for families and adults this winter. Register online or at 703-228-4747.

Hawks in Arlington

Saturday, Feb. 11, 9 – 11:30am
Adults. Red-tailed, Red-shouldered, Cooper’s and Sharp-shinned Hawks all call Arlington home. We’ll learn to tell these four hawks apart and how they survive in urban areas. After our discussion, we’ll go out to look for hawks and other birds. Teens ages 12 and up are welcome. For information: 703-228-6535. Meet at Long Branch Nature Center. $10. #622947-J

Northern Virginia Bird Club walks

Join members of the Northern Virginia Bird Club for one or all of these informal walks through Long Branch and Glencarlyn Parks in search of resident and migratory birds. Experienced and beginning birders welcome. Bring binoculars and field guides if you have them. For information: 703-228-6535. Meet at the parking lot at Long Branch Nature Center. Free.

Wednesday, Dec. 7, 9:30 – 11am #622947-D;

Wednesday, Jan. 4, 9:30 – 11am #622947-E

Wednesday, Feb. 1, 9:30 – 11am #622947-F

 Owl Pellet Dissection

Saturday, Jan. 14, 1 – 3pm
Ages 10 to 17. Use your detective skills to dig carefully through owl pellets to find the bones of what owls eat. Then we’ll reconstruct the skeletons to discover what animals were eaten. You will get to take home your findings! $10. #622927-E

Birding Arlington!

Families ages 8 and up. Join our new bird watching series for families! We’ll visit different birding spots in Arlington throughout the year and build our County bird lists. Birders of all experience levels can participate and loaner binoculars are available. For information: 703-228-3403. Free.

Winter Bird Hike to the Potomac

Saturday, Jan. 14, 8 – 9:30am
We’ll explore the forests in search of winter birds, including Brown Creeper, Winter Wren and Yellow-bellied Sapsucker. Then hike to the Potomac River to search for waterfowl. One mile round trip over irregular terrain. Meet at Gulf Branch Nature Center. #622857-I

Waterfowl at Gravelly Point

Saturday, Feb. 4, 8 – 9:30am
Gravelly Point is a great spot for viewing winter waterfowl on the Potomac. We will bring spotting scopes, and stroll around the park looking for winter specialties and maybe a Peregrine Falcon. Flat terrain. Meet at Gravelly Point – George Washington Memorial Pkwy, Arlington. #622857-J