DEEP: Special Report on Wetland Bird Survey

Survey Sheds Light on Wetland Bird Species
Adapted from an article that appeared in the November/December 1999 issue of  Connecticut Wildlife.

{Least Bittern Photo}
The state-threatened least bittern was heard at six sites during the 1999 wetland call-back survey.

Habitat loss of both freshwater and tidal wetlands, combined with degradation of remaining wetland resources, has resulted in population declines in several wetland-dependent bird species. Many of these birds have declined to such an extent that they have become part of Connecticutís endangered, threatened and species of special concern list.

To help protect these birds and their habitats, it is important for biologists to know which wetlands are currently being used by the birds. Unfortunately, many wetland-dependent birds are very secretive and difficult to census or study using the same techniques that are used for songbirds. However, wetland birds will often respond to tape-recorded calls and can be monitored to some extent using a call-response survey. Using this type of survey, tape-recorded calls are played in suitable habitat and often evoke a territorial response by any male birds present. Care must be taken not to repeat this technique too often during the nesting season to prevent overstressing the birds and jeopardizing their survival. For this reason, it is not a good idea to use call-response tapes for general bird observation purposes.

Since 1993, the Wildlife Divisionís Nonharvested Wildlife Program has used a call-response technique in May, June and July to survey wetland birds. In 1999, 20 volunteers surveyed 43 wetland sites located throughout the state. Three of the most secretive wetland nesters, the American bittern, least bittern and pied-billed grebe, were recorded during the survey. As in years past, members of the rail family were detected more frequently than the other wetland birds. Virginia rails, one of the most abundant species, were found at 16 different sites. Sora, king and clapper rails were also detected during the surveys. Willet numbers continue to increase at coastal survey locations.

{Clapper Rail Photo}
Clapper rails are found at coastal salt marshes.

As the next wetland bird survey approaches, the Wildlife Division is once again looking for help from experienced birders. Participants will be asked to survey locations in late May, twice in June and once in early July, beginning at sunrise, any day of the week. Call tapes and cassette players will be provided. Some of the sites can be difficult to reach and may require the use of chest waders or rubber boots. Other sites can only be surveyed by canoe or kayak. If you would like to join the volunteer ranks for the 2000 season, please contact the Nonharvested Wildlife Program at the Sessions Woods office (860-675-8130).

The Wildlife Division appreciates the help of all the dedicated volunteers who assist in the wetland call-back surveys. Without their continued assistance, it would be impossible for this statewide survey effort to continue.


1999 Wetland Call-back Survey Results
(updated 12/21/99)


No. of sites heard

American Bittern


Least Bittern


Virginia Rail




Clapper Rail


King Rail


Black Rail


Common Moorhen


Pied-billed Grebe