American Crow (Corvus brachyrhynchos)

About the Bird

Seen/Heard at
Decorah, Decorah North, Great Spirit Bluff

Diet
American crows eat almost everything, including grains, seeds, nuts, fruits, berries, insects, worms, fish, young turtles, mice, crayfish, mussels, clams, the eggs and nestlings of other birds, carrion, and garbage. Having said that, adults tend to have more plant than animal matter in their stomachs, while young tend to have more animal than plant matter. Crows may cache food and have been observed eating desired foods or parts of food immediately while caching less desired food for later: something we have also observed in bald eagle nests. Crows are primarily ground foragers, although they eat from fruiting trees and shrubs and have been observed coming to birdfeeders. They will also feed along the edges of fresh and salt water and wade in shallow water up to their bellies.

Nesting
Both members of a breeding pair help build nests, and young birds from the previous year may sometimes help as well. American crows build stick nests with an inner cup lined with pine needles, weeds, soft bark, and hair. Between mid-March and mid-June, they lay three to nine bluish-green to olive eggs marked with brown and grey, although pigment patterns and egg colors vary widely.  Females incubate eggs for 16-18 days and usually produce one brood per year, although American Crows may produce a second clutch if the first one is destroyed. Initially, males and helpers provide food for the female and nestlings, although females help provision more once young are able to thermoregulate. Young stay in the nest for 28-35 days prior to fledging.  To learn more, visit Cornell’s website.

Crows are considered highly intelligent. They have exceptionally large forebrains, the domain of analytical thought, higher-level sensory processing, and flexible behavior. You can read more about their intelligence here: https://www.audubon.org/magazine/march-april-2016/meet-bird-brainiacs-american-crow

Citations
Bird Range Maps of North America
Ridgely, R.S., T.F. Allnutt, T. Brooks, D.K. McNicol, D.W. Mehlman, B.E. Young, and J.R. Zook. 2003.
Digital Distribution Maps of the Birds of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA. Data provided by NatureServe in collaboration with Robert Ridgely, James Zook, The Nature Conservancy – Migratory Bird Program, Conservation International – CABS, World Wildlife Fund – US, and Environment Canada – WILDSPACE.
Web Link: http://bit.ly/2ynPQ5I
Cornell Laboratory Birds of North America. Link: https://birdsna.org/Species-Account/bna/species/amecro/

General Description
A medium-sized, all-black bird, although new feathers may be a glossy violet, while older feathers can appear brown or cloudy. American Crows have stout, glossy black bills, black legs and feet, nares covered with stiff, bristlelike feathers, and a brown iris. The tips of their folded wings do not reach the tips of their tail at rest, and their tail is slightly rounded.

Migration
Like birds of prey, American Crows are diurnal migrants. They can be found in the Decorah area year-round, although some winter crows could be migrants from colder northern areas.

Measurements
Length: 15.8–20.9 in/40–53 cm
Wingspan: 33.5–39.4 in/85–100 cm
Weight: 11.2-21.9 oz/316–620 g

Wing Design
Broad and rounded – closest to a passive soaring wing. Crows are perhaps the bird most likely to trick me at a distance: they might soar like Red-tailed Hawks, dive quickly like Peregrine Falcons, or fly like American Robins through a woodland.

Videos
https://youtu.be/bx_L–t0bXg

Range Map

Range Map