Abstracts

Presented by Michael L Schummer - Email: mlschumm@esf.edu

In the Atlantic Flyway, lesser snow geese (Chen caerulescens caerulescens; LSGO) as depicted as migrating through central and western New York, whereas greater snow geese (Chen caerulescens atlantica; GSGO) are confined to eastern New York. Anecdotal evidence from hunters and birders indicated this pattern may be true during autumn migration, but it was thought that GSGO were increasingly migrating through central and western New York during spring. Our study focused on New York because it represents a substantial percentage of the total Atlantic Flyway snow goose harvest during spring migration and is the eastern boundary of most snow goose migration. LSGO and GSGO also are sympatric here during winter and migration and presumably begin to separate into different migratory pathways towards geographically separated breeding areas. We used head morphology, discriminant function analysis, and genetic testing (i.e., sex determination) of snow geese harvested during spring (n = 1,704) to differentiate between LSGO and GSGO and describe their migratory pathways through New York, 2016 - 2018. We also used autumn and spring band recoveries to test for seasonal differences in migration. We detected LSGO and GSGO in the harvest throughout New York, with proportions of 20% LSGO and 80% GSGO. Mean longitude of GSGO band recovered differed between autumn (73.8W) and spring (76.0W) migration and the harvest distribution shifted west between the 1990s and 2010s. Band recoveries of LSGO in New York are limited (n = 6), but our results suggest a greater abundance migrating through New York which may indicate that these LSGO are derived from colonies that are not currently banded. Results can be used in harvest management strategies to understand the spatial distributions of LSGO and GSGO harvest and proportions of these sub-species in the harvest.