Seymour Benzer 1921–2007 The Man Who Took Us from Genes to Behaviour

Seymour Benzer died suddenly in December 2007. This piece pays tribute to Seymour Benzer's pioneering work in solid state physics, molecular biology, and neurogenetics

Pairwise Interactions in Chimney Swift Flocks

Chimney swifts, Chaetura pelagica, are small (0.3 m wingspan) insectivorous birds which roost overnight in chimneys during their fall migration. Hundreds to thousands of swifts flock and roost together, necessitating the formation of enormous, cylindrical holding patterns as the flock slowly enters its chimney each evening. Despite the large size of the flock, previous studies identified no internal organization and found that swifts typically maintain five or more wingspans distance from their neighbors. However, recent analysis of shorebird flocks revealed organized subgroups within larger less organized flocks, raising the possibility that such subgroups could also exist within the chimney swift roosting flock. I hypothesized that subgroup structure might be present between reciprocal nearest neighbors (RNNs), or two birds who were closest to one another and that RNNs would be more aligned with one another than non-RNNs, independent of distance and fly in a consistent formation. To test this hypothesis, I used data on a flock of chimney swifts in Raleigh, NC collected using three synchronized video cameras and then digitally reconstructed the individual birds’ positions. Measurements of alignment showed that RNNs were more closely aligned than non-RNNs. However, RNNs also tended to be closer together than non-RNNs. Once this difference in average distance was factored in, RNNs and non-RNNs were similarly aligned with similar spatial distributions. Thus, my hypothesis was not supported. Ultimately, a deeper understanding of how swifts determine and maintain their spacing will still continue to contribute to the development of collective behavior models.Bachelor of Scienc