Distribution, species abundance, and nesting-site use of Atlantic coast colonies of herons and their allies

In 1975 and 1976, eight teams of investigators located 262 colonies of nesting herons and their allies along the Atlantic coast from Florida to Maine. Fourteen species were found in Florida, numbers decreasing to seven in Maine. Colonies censused in the extreme south and north of the study area were lower in number of species and number of adults than those in the intermediate area. More than 90% of the colony sites surveyed in 1975 were active in 1976. The total number of nesting adults per colony, number of species per colony, and number of nesting adults of each species per colony in 1976 were significantly correlated with their respective values for 1975. Abandoned and new colonies appeared to be satellites of nearby reused colonies; they had fewer individuals and species than reused colonies and were closer to reused colonies than reused colonies were to each other.