Vireo, Blue-headed

KEY

Detectability

Regular (expected annually; defined as the average number of individual birds per birding day, week, or month expected by an experienced observer under normal circumstances in the proper habitat at the optimum time of season):

P= Permanent Residents (although wild birds are possible; look for clipped wing)
AB = Abundant (30+ per day)
VC = Very Common (10-30 per day)
C= Common (3-10 per day)
FC = Fairly Common (1-3 per day)
U = Uncommon (2 per week to 1 per day)
VU = Very Uncommon (3 per month to 2 per week)
R = Rare (1-3 per month)

Irregular (absent some years; defined as an average of one record by all observers in the stated number of years):

O = Occasional (1-3 years)
CA = Casual (3-11 years)
AC = Accidental (11+ years)

Designations for winter water birds are based on periods when lakes are mostly icefree.

Breeding

(***) Confirmed
(**) Probable
(*) Possible
(~)  Captive birds

Seasons

Spring (March 6 - June 5)
Summer (June 6 - August 15)
Fall (August 16 - November 30)
Winter (December 1 - March 5)

Bird Photographs: Jim Ault, Carol Freeman, Jim Steffen.