Thomas Custer (Former Employee)

Eggs of Black-crowned Night-Herons (Nycticorax nycticorax) were collected in 1979 from two colonies in North Carolina, two colonies in Rhode Island, and one colony in Massachusetts. Mean concentrations of DDE and PCBs were higher in the New England samples than in those from North Carolina, Mean concentrations of organochlorine contaminants in addled eggs collccted at two New England...

Aquatic birds may serve as indicators of regional metal contamination. Because the food of prefledgling herons (Nycticorax nycticorax ) comes only from areas near the colony, their tissues should reflect local metal contamination. The authors' hypothesis was that prefledgling herons from the Rhode Island colony should have higher concentrations of metals than do those from either the...

Day-old cockerels received 1850 ppm dietary lead for 4 wks. Blood delta-aminolevulinic acid dehydratase (ALAD) activity was reduced to 1.6% of control activity by the end of the study. Hemoglobin concentration (Hb) in lead-exposed cockerels was significantly less than that of controls at 7, 14, and 28 days, and packed cell volume (PCV) was significantly reduced at 14 days. Blood lead...

To estimate reproductive success in a population one ideally would like to determine the number of young fledged per nesting female. However, this is difficult because often (1) the adults are not individually marked, (2) the colony is not visited daily, and (3) the investigator is unable to monitor all young until they fledge. If adults are unmarked and successful renesting occurs...

There have been few consistent reports concerning the frequency and success of nesting attempts by immature night herons of the genus Nycticorax. One- year-old Black-crowned Night Herons (Nycticorax nycticorax) mated to 2-yr-old or older birds built nests and incubated eggs in the wild (Gross 1923). In a captive colony, many 1-yr-old pairs of night herons courted and built nests, and one...

No abstract available.