. 2015. Anti-predator defenses of Brown Bullheads (Ameiurus nebulosus) and interactions with Snapping Turtles (Chelydra serpentina). Canadian Field-Naturalist 129(2): 189-193.Ictalurid catfishes have sharp spines on their dorsal and pectoral fins that can be hazardous to predators. The pectoral spines may lock in an abducted position, effectively increasing body size and preventing ingestion by gape-limited predators. Further, sharp spines may injure predators or increase prey handling time, affording catfish opportunities for escape. As part of a longterm mark-recapture study of turtle ecology in Algonquin Provincial Park, Ontario, Canada, we documented the presence of Brown Bullheads, Ameiurus nebulosus, in the diet of Snapping Turtles, Chelydra serpentina. Here, we report on injuries inflicted by the pectoral spines of bullheads on Snapping Turtles during predator-prey interactions and provide a brief literature review of the functional significance and potential dangers of catfish pectoral spines to predators.

Many oviparous reptiles nest in aggregations and with temporal synchrony. We hypothesized that these traits reflect attraction by conspecifics rather than limiting suitable habitat. We quantified whether Painted Turtles (Chrysemys picta (Schneider, 1783)) in Algonquin Park, Ontario, were nesting communally, identified cues females used to select nest sites, and tested whether hatching success was higher in spatially-clustered nests. We found that nests were closer to one another than expected by chance (i.e., were clustered), but that individual nest site selection was only weakly influenced by micro-habitat characteristics. Survival of clustered nests (49%) was not significantly higher than that of solitary nests (39%). When turtle models were placed on the nesting embankment, females nested most often with the highest density of models. Given that reproductive lifespan is the major axis of fitness and that there was little benefit to nest survival in clustered nests, we suggest that clustering is related to females cueing to conspecific nests to expedite the nesting process and gain a good-quality nest site (chosen by the first nesting female in the cluster) while investing little energy in nest-site selection. This strategy may reduce time spent on land, thereby minimizing chances of dehydration, temperature stress, and adult depredation.