American crow (Corvus brachyrhynchos)
CONFIRMATION STATUS: Confirmed.
The number of American crows in northern Virginia was significantly
depleted in 2004 with the introduction of the West Nile virus. West Nile
virus was first identified as entering through New York City in the late
1990s, rapidly spreading through humans and at least 326 species of birds.
While human infection has proven to be relatively mild (most infections
go unnoticed and the mortality rate is much less than 1%), infections of
different bird species has proven to be much more series. American crows
in particular have been devastated, with a 100% death rate for infected birds.
Nearly half of American crows were killed in northern Virginia by 2004 and
while their numbers have been recovering, it will take several years for
them to completely rebound. In addition, there is no indication that
American crows have developed immunity to the disease; another flare-
up of the disease could decimate the species.
One explanation of the rapid spread of West Nile virus among American
crows is the breeding and overwintering behavior of the birds. American
crows form close family associations during breeding season, while during
the winter the birds join large flocks. In both cases, infected birds are in
close association with other crows, allowing for epidemic conditions to
Length: 17 inches
Entirely black plumage
Very common in urban and agricultural areas
Fish crow very similar but has different call. Northwestern crow also
very similar but has different range. Ravens are similar but larger with
wedge-shaped tails and different calls.
Migration Status: Short distance migrant
Breeding Habitat: N/A
Nest Location: Mid-story/canopy nesting
Nest Type: N/A
Clutch Size: 3-8
Length of Incubation: 18 days
Days to Fledge: 28-35
Number of Broods: 1, 2 in south
Diet: Mostly seeds; lesser quantities of insects, carrion, fruit, nuts,
SKY MEADOWS DISTRIBUTION/SEASONAL OCCURRENCE
Relative abundance and seasonal occurrence are indicated in red below.
C - Common: Likely to be present in good numbers in appropriate habitat and season.
U - Uncommon: May be present in appropriate habitat and season, often in low
O - Occassional: Found in appropriate habitat perhaps only a few times per season,
sometimes low numbers.
R - Rare: May not be recorded every year.
Acc - Accidental: Recorded once or twice, may not be expected again for a long time.
Sp - Spring: March, April, May C
Su - Summer: June, July, August C
Fall: September, October, November C
Winter: December, January, February C
Crooked Run Valley