Tudor Wharf Draft Environmental Impact Report EOEA # 6744 



26 days from laying date (Gross 1923, Noble 

 et al. 1938) . 



Longevity 



No studies of the average or maximum 

 longevity of black crowned night herons have 

 been found in the literature. Eric Strauss of 

 Tufts University suggested that average life 

 expectancies are probably in the range of 4-8 

 years though some individuals probably live 

 considerably longer. 



Relationships Between Young and Adults 



Once they have escaped the security of the 

 egg (which, according to Gross (1923) is "a 

 somewhat prolonged process"), the young are 

 able to hold themselves upright in the nest 

 within one day. Soon after hatching the 

 chick commences begging for food. Black- 

 crowned night herons feed their young 

 regurgitated food, primarily fish. To 

 solicit adults to regurgitate food young 

 herons have been reported to "...seize the 

 parent's bill nearly at right angles and [we] 

 assume this is the typical method of 

 receiving regurgitated food from the parent 

 (Noble and Wurm 1942)." Hatchlings typically 

 fledge within 4 to 6 weeks after hatching. 



Breeding in First Year Birds 



Breeding has been reported for first year 

 birds by several investigators (Gross 1923, 

 Noble et al. 1938, Custer and Davis 1982). 

 This is interesting in that black-crowned 

 night herons do not attain their adult 

 plumage until after their third summer (Gross 

 1923) . Custer and Davis (1982) collected 

 detailed observations of a breeding pair of 

 one year old herons, and a mixed-age breeding 

 pair of a one and a two year old. Their 

 findings documented the first occurrence of a 

 pair of breeding one year old black-crowned 

 night herons in the wild. Both nesting 

 attempts occurred late in the season with 

 smaller than average clutch sizes (3 eggs in 



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