Research Briefing: Snail Kites with Caroline Poli
Caroline Poli is an SNRE PhD student in the Fletcher lab. Her research concerns the snail kites (Rostrhamus sociabilis) of southern Florida.
Survival of Snail Kites from fledging to 1-year is important for growth and recovery of the endangered population in south Florida.
Post-fledging dispersal of juvenile birds is important for future survival and recruitment; however, understanding of the timing and drivers of movement is currently limited. We therefore sought to determine post-fledging movement patterns and factors that influence movement patterns in Snail Kites across the Greater Everglades ecosystem.
We GPS-tracked 14 fledgling Snail Kites across six wetlands, 2016-2017, and found that movement patterns varied substantially within and between individuals, but that birds remained within 900 meters of the nest site for up to 58 days post-fledging. During that time, birds explored surrounding wetlands using occasional foray flights that began and ended at the natal wetland, and were characterized by rapid, moderate-distance movements. After birds departed the natal site and arrived at a new area, movements were highly localized and birds ranged less than 5 km/day.
We further evaluated whether fast, exploratory movements between wetlands were characterized by visual cues such as vegetation,
or transport-related cues such as thermals and wind.
We found that, although visual cues corresponded to movement most frequently, neither visual or transport-related cues explained movement strongly. Given the lack of information about post-fledging movements of Snail Kites, our data will aid in the identification of factors that influence first-year movements and survival, and provide essential information for conservation of Snail Kites across the full-annual-cycle.