Colonial Wading Bird Populations Monitoring on
​West Sister Island National Wildlife Refuge 

This is a cooperative project with the U.S. Fish and Wildlife Service, Ohio Division of Wildlife, and the Observatory. The Observatory is responsible for banding a sample of the herons and egrets on the island to provide information on the dispersal of these birds. The island holds 40% of all the nesting herons and egrets in the U.S. Great Lakes. Monitoring of the population has become increasingly important due to the expansion of the Double-crested Cormorant and the resulting habitat loss. Black-crowned Night-Heron Populations have been declining on the island to well below 500 pair. They once reached a high of 1,200 pair on the island. The Black-crowned Night-Heron has been designated a bird species of concern in the Great Lakes by the USFWS.  

West Sister Island Colonial Wading Bird Breeding Pair Survey 1991 - 2014  

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Banding recoveries have been found in Southeast Michigan, Illinois and Ohio. 
Around 30 recoveries have been reported from areas outside Ohio, Caribbean, and Mexico.