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G.R. Costanzo

Publications and source records attributed to G.R. Costanzo.

3 recordsLinked to original sources

Islands at bay: Rising seas, eroding islands, and waterbird habitat loss in Chesapeake Bay (USA)

Like many resources in the Chesapeake Bay region of the U.S., many waterbird nesting populations have suffered over the past three to four decades. In this study, historic information for the entire Bay and recent results from the Tangier Sound region were evaluated to illustrate patterns of island erosion and habitat loss for 19 breeding species of waterbirds. Aerial imagery and field data collected in the nesting season were the primary sources of data. From 1993/1994 to 2007/2008, a group of 15 islands in Tangier Sound, Virginia were reduced by 21% in area, as most of their small dunes and associated vegetation and forest cover were lost to increased washovers. Concurrently, nesting American black ducks ( Anas rubripes) declined by 66% , wading birds (herons-egrets) by 51%, gulls by 72%, common terns (Sterna hirundo) by 96% and black skimmers ( Rynchops niger ) by about 70% in this complex. The declines noted at the larger Bay-wide scale suggest that this study area maybe symptomatic of a systemic limitation of nesting habitat for these species. The island losses noted in the Chesapeake have also been noted in other Atlantic U.S. coastal states. Stabilization and/or restoration of at least some of the rapidly eroding islands at key coastal areas are critical to help sustain waterbird communities.

Virginia

Avian cholera in ospreys: first occurrence and possible mode of transmission

In 1994, six Ospreys (Pandion haliaetus) were recovered during the later stages of an epizootic of avian cholera (Pasteurella multocida) in diving ducks and seabirds on Chesapeake Bay in Maryland and Virginia. Pasteurella multocida was isolated from four Ospreys submitted for bacterial examination. This is believed to be the first report of avian cholera in Ospreys. The same isolate, serotype 3,4, was isolated from the Ospreys, diving ducks,and seabirds collected during the epizootic. Possible modes of transmission of avian cholera in Ospreys were either the ingestion of sick waterfowl or use of infected carcasses or bones as nest material.

Maryland, Virginia

Winter movements of American black ducks in relation to natural and impounded wetlands in New Jersey

Radio telemetry was used to follow the movements and habitat use of female American Black ducks (Anas rubripes) trapped at Brigantine Division. Edwin B. Forsythe NWR (BNW) during three field seasons (1983-1896). Use of the BNWR impoundments was strongly associated with open vs. closed hunting seasons and with presence or absence of ice cover. Black ducks primarily used the impoundments for daytime roost sites and fed in saltmarsh areas at night during the hunting season. Following the hunting season use generally dispersed to saltmarsh and inland freshwater habitats. Freeze-up of the impoundments resulted in dispersal of black ducks to saltmarsh, inland freshwater, or areas to the south of New Jersey. We conclude that the BNWR impoundments only partially meet the habitat requirements of wintering black ducks. Access to saltmarsh habitats for feeding, and to inland freshwater habitats during periods of hard freeze, may be critical. The utility of the BNWR impoundments to black ducks, needs to be considered in conjunction with the availability of these other important habitats.

Book chapter