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QUALIFYING VARIATION IN RISKS ACROSS SPACE AND TIME TO POPULATIONS OF THE COMMON LOON
Citation:
Nicholson, M. C., R Haebler, AND M. Pokras. QUALIFYING VARIATION IN RISKS ACROSS SPACE AND TIME TO POPULATIONS OF THE COMMON LOON. Presented at 19th Annual Symposium of the United States Regional Association of the International Association for Landscape Ecology, Las Vegas, NV, March 30-April 4, 2004.
Description:
As part of a larger project to evaluate methods for assessing risks to wildlife populations we are investigating patterns of mortality in populations of the common loon (Gavia immer) in New England. Regionally, loon populations have declined from historic levels and despite recent range-wide increases, loon numbers have declined in some areas. Using morbidity and mortality data collected on common loons since 1988 we are quantifying spatial and temporal patterns of risk in New England. From 1987 to 2000, lead toxicosis was the leading cause of death in adult breeding loons. Based on spatial scan statistics, spatio-temporal clustering in lead-induced mortality was detected in the study area with a higher risk occurring in central New England during the first half of this study. The location of risk and the timing of decrease suggest that a public education program aimed at reducing the use of lead sinkers in New England was successful. Patterns in other sources of morbidity and mortality also are revealing clear space-time patterning in risk. As patterns in mortality are more accurately quantified it is hoped that a better understanding of the underlying spatial processes affecting risks to loon populations in New England will result.