Fish Cliques: Evidence of Social Groups from Sparse Observations in Time and Space?

POSTER presented at Joint Statistical Meetings, 2 August 2016, Chicago, IL

1. Fish Cliques: Evidence of Social Groups from Sparse Observations in Time and Space ? USGS - Great Lakes Science Center: Jean Adams, Stephen Riley, Taaja Tucker Michigan State University: Charles Krueger, Thomas Binder EMAIL: JVAdams@usgs.gov TWITTER: @JeanVAdams GITHUB: JVAdams In Lake Huron, 60,000 detections of 250 tagged fish at 30 stations Lake Trout Same station: 4 days Both observed: 7 days Together: 4 / 7 = 57% Unique stations: 3 Detections for one pair of fish • Hypotheses – H0 : seasonal movement patterns – HA : synchronized "group movement" • Identify groups that move together – together > 50% 11 pairs of fish – > 2 unique stations 17 individuals Detections for all pairs of fish observed • Randomization – Add time shift from -3 to +3 days to each fish – Identify groups – Repeat 100 times – Mean no. fish in groups: 10.7 (7, 18) • Groups we observed are what we would expect by chance • No evidence of "fish cliques" Lake Trout