This is rather late but might be of interest. Last Tuesday, 16 May, I saw 2 Black-crowned Night Herons by the pond at Patterson Park. One was a 1st summer  bird with smooth grey-brown plumage and a dulled down version of the adults black crown. The other had juvenile plumage of pale beige-brown with a streaky breast and white spots on the wing coverts. The latter bird was clambering around on the bare branches of a fallen dead tree in a rather awkward manner, which gave the impression of a recently fledged bird. 

Looking at the reported breeding dates in the first Maryland breeding bird atlas, the juvenile must have come from an unusually early nest. The Atlas states that egglaying starts in mid-April in Maryland, although Stewart and Robbins (1958) reported nestlings in DC as early as 22 February.  Back-counting using the 24-36 day incubation period and 6 week nestling period given in the Atlas, I estimate that this juvenile must have come from an egg laid before 10 March.  Were any of the nests in Baltimore known to be active so early?

Dave 

David Curson, PhD
Director of Bird Conservation,
Audubon MD-DC,
2437 Eastern Avenue,
Baltimore  MD  21224
Tel: (410) 558 2473
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