Family: Herons, Bitterns, and Egrets (Ardeidae)
Migratory Bird Treaty Act
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Did you know?
Great Blue Herons have been known to choke to death when trying to swallow a fish that is too large.
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Great Blue Herons are considered a local and common breeder in upstate New York. The second Breeding Bird Atlas reported 478 confirmed breeding blocks (McGowan and Corwin 2008) representing breeding in 55 of 62 counties. The number of confirmed breeding blocks has doubled since the first Breeding Bird Atlas (Andrle and Carroll 1988 and McGowan and Corwin 2008). While populations appear to be stable, habitat loss still poses a threat to this species. At this time, New York Natural Heritage tracks rookeries with greater than 50 active nests. Most rookeries in New York have fewer than 50 active nests.
It appears that there has been an increase in Great Blue Heron rookeries between the first Breeding Bird Atlas (1980-1985) and the second Breeding Bird Atlas 2000 (2000-2005) with the number of confirmed breeding blocks increasing from 212 to 478 blocks (Andrle and Carroll 1988, McGowan and Corwin 2008). Great Blue Herons continue to nest in nearly all of New York State excluding the Coastal Lowlands (McGowan and Corwin 2008). Breeding Bird Survey analysis indicates a slight delcine of 0.7% per year between 1980 and 2006 (Sauer et al. 2007).
Great Blue Heron populations decreased during the late 1800s and early 1900s, mostly due to shooting and habitat loss. Breeding populations along the Coastal Lowlands were eliminated in New York. Populations most likely started to rebound with the recovery of beaver populations in the state. Beaver activities resulted in flooding of lowlands that provided additional nesting and foraging habitat for Great Blue Herons. A five-year study conducted with the Federation of New York Bird Clubs (currently known as the New York State Ornithological Association) to assess Great Blue Heron populations found that 41 rookeries were active for at least one year during the study period. Aerial surveys of 110 rookeries that were reported by various scientific organizations and scientists were conducted between 1972 and 1981. These surveys concluded that Great Blue Heron nesting abundance likely increased since the mid-1960s (Andrle and Carroll 1986). Breeding Bird Survey analysis indicated a population increase of 1.4% per year from 1966 to 2006 (Sauer et al. 2007).