Geology topics

John T. Seginak

Publications and source records attributed to John T. Seginak.

4 recordsLinked to original sources

USGS2019

Annual survival, site fidelity, and longevity in the eastern coastal population of the Painted Bunting (Passerina ciris) based on a 20-year mark-recapture/resighting study

A long-term study of annual survival, longevity, and site fidelity in the eastern coastal population of the Painted Bunting (Passerina ciris) during the breeding season was conducted from 1999 through 2018 in the outer coastal plain of the southeastern Atlantic coast of the United States. Painted Buntings were uniquely color-banded from 1999 through 2003 at 40 study sites that were paired at 20 locations from southeastern North Carolina south to northeastern Florida. Survival analysis used capture histories through 2005 for 994 birds banded as hatch-year and 2420 birds banded as post-hatch-year (adults). Annual estimates of apparent survival (1999-2004) averaged 0.71 and 0.66 for adult males and females, respectively, and 0.33 for hatch-year birds. We did not find evidence that survival differed in relation to latitude or extent of human development near study sites, although estimates for adult females were higher for birds banded on sheltered islands compared to the mainland. Expected time in the population, based on estimated survival, was 3.9 and 3.4 years for adult males and females, respectively. The oldest observed birds were a 14-year old male observed in June 2016 at Harris Neck NWR, Georgia, the site at which he had been banded in July 2003 as a second-year bird, and a 13-year old male seen at Ft. George Island, Florida in June 2016, 2 km across a tidal estuary from the site where the bird was banded in August 2003 as hatch-year. The males were sighted at these two sites in 9 and 11 different years, respectively. Overall, 78% (males) and 81% (females) of re-sightings and re-captures of birds banded as adults occurred at the same study site where individuals were banded, compared to 59% (males) and 60% (females) of birds banded as hatch-year. Known mortalities of banded buntings included nine birds trapped for the caged-bird trade. This study shows the potential for high survival and longevity in the eastern coastal population of the Painted Bunting, and given evidence of high site fidelity in the breeding range, the vulnerability of the population to human development along the southeastern U.S. coast as well as to illegal trapping.

Wilson Journal of Ornithology↗

USGS1995

Habitat use at night by wintering American woodcock in coastal Georgia and Virginia

Nocturnal habitats used by American woodcock ( Scolopux minor ) were studied using radio telemetry at two coastal wintering sites in Georgia (1982-84) and Virginia (1991-92). In Georgia, use of forested habitats at night was extensive while use of fields at night varied between years but generally was low. We found no difference in the probability of moving to a field at night among the four age-sex classes ( P = 0.23). A significant effect ( P < 0.05) of age-sex class was noted between distances moved from diurnal to nocturnal locations in Georgia. Young females moved farther than any other age-sex class. In Virginia, no effect of age-sex class was found on the probability of being located during the night in either a field or a forest.

Georgia, Virginia↗

USGS1994

Dioxins and furans linked to reproductive impairment in wood ducks

A wetland in central Arkansas was contaminated with polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans and because the area was a major waterfowl habitat, we studied the effects of the contamination on nesting wood ducks ( Aix sponsa ) during 1988-90. Residues in wood duck eggs, based on toxicity equivalency factors (TEFs) for combined compounds, ranged from 0.2 to 611 parts per trillion (ppt) wet mass (70% were the toxic isomer 2,3,7,8-tetrachlorodibenzo-p-dioxin (tetraCDD)) and were 50 times higher in eggs from near the point source than from an uncontaminated reference site 111 km away. Nest success, hatching success, and duckling production were suppressed ( P < 0.05) at nesting sites 9 and 17 km downstream, as was hatching success 58 km downstream. Egg TEFs were inversely correlated ( P < 0.001) with productivity in corresponding nests. In addition, teratogenic effects occurred in ducklings at the more contaminated nesting site nearest the point source. The threshold range of toxicity (based on TEFs) where reduced productivity was evident in wood ducks was gt 20-50 ppt. Wood ducks were sensitive to dioxin and furan contamination, and we recommend it as an indicator species for monitoring biological impacts from these contaminants.

Arkansas↗

USGS1994

Survival rates of American woodcock wintering along the Atlantic coast

Because American woodcock ( Scolopax minor ) populations have been declining, we attached radio transmitters to woodcock at coastal plain sites to determine if survival during winter was involved in the decline. Sites were in Georgia (1982-84, 1989-92), South Carolina (1988-89), and Virginia (1991-92). Survival rates were not different between age or sex classes. Survival rates differed ( P = 0.003) among years. Daily survival rates were lowest ( P = 0.030, S = 0.987) during 1982-83 in Georgia and highest ( P = 0.004, S = 0.999) during 1990-91 in Georgia than in the other years and locations combined ( S = 0.996). We attributed all mortality to raptors and mammals. Compared with other periods of the year, winter was a time of low survival for woodcock. Lower survival rates were possibly a cause of population decline.

Georgia, South Carolina, Virginia↗