Residence and movement patterns of cownose rays Rhinoptera bonasus within a southwest Florida estuary

tracked within Pine Island Sound estuary, Florida, using passive acoustic telemetry. Residence time of individuals ranged between 1 and 102 days. No relationship was detected between ray activity and tidal stage or time of day. Minimum convex polygons (MCP) and kernel utilization distributions (KUD) were calculated over several time frames to demonstrate the extent of an animal’s home range and core areas of use. Total MCPs ranged between 081 and 7178 km2 (mean 2201 km2), with daily MCPs as large as 258 km2. Total 95 % KUDs ranged between 018 and 6244 km2 (mean 2263 km2), while total 50 % KUDs were smaller, ranging from 009 to 968 km2 (mean 333 km2). Both MCP and KUD areas exhibited a positive relationship with residence time and R. bonasus size. As mobile, pelagic swimmers capable of traversing large distances, these data show that cownose rays travel extensively throughout this estuary, yet may remain within very small areas for extended periods. # 2007 The Author