Study site
The study was conducted in the experimental ponds of the University of
British Columbia, Vancouver, Canada (49°14’56” N, 123°14’02” W). The
site has a total of 20 artificial ponds, each of dimensions 15×25 m²,
arrayed across an area of 130×100 m². The two dominant species we
studied, Anax junius and Rhionaeschna multicolor, are
among the largest and highly mobile dragonflies in North America
(Paulson, 2009).