Studying mate choice in the wild using 3D printed decoys and action cameras: a case of study of male choice in the northern map turtle

Mate choice experiments are essential to further our understanding of sexual selection, but can be challenging to design and conduct with most wild animals. 3D printing technology is creating opportunities to conduct mate choice experiments in the field by facilitating the production of biologically accurate decoys. We used pairs of 3D printed female decoys differing only in size to test whether free-ranging male northern map turtles, Graptemys geographica, prefer larger females. Males interacted and attempted to mate significantly more with the larger decoys. By selecting larger females, males should increase their fitness because of the correlation between female size and hatchling size. Our experiment demonstrated that 3D printing technology can be a valuable tool to study animal behaviour in the field

Using behavioral observations to develop escape devices for freshwater turtles entrapped in fishing nets

The drowning of freshwater turtles following incidental capture in fishing gear has the potential to cause population declines. Fyke nets can be equipped with bycatch reduction devices that enable the escape of turtles before they drown. We employed quantitative and qualitative behavioral observations (with action cameras deployed underwater) to develop a new, collapsible, escape bycatch-reduction device that mounts internally in the terminal end of a fyke net. We also used behavioral observations to identify areas of the net most used by turtles, thus revealing the most logical placement for an escape bycatch-reduction device. When turtles were introduced into modified nets, escape was rapid (mean of 12.4 min), with 100% escape for map Graptemys geographica and musk turtles Sternotherus odoratus and 94% escape for painted turtles Chrysemys picta. Our preliminary field trials indicated that modified fyke nets decreased the capture rate of turtles relative to unmodified nets. Escape devices can be used as a key component of a bycatch reduction program and be particularly effective when paired with exclusion bycatch-reduction devices. The escape device developed in this study can potentially be used in the local fishery or modified for other fisheries. The use of behavioral observation to guide the development of bycatch reduction devices may provide an extra tool for managers to increase selectivity and maintain sustainable harvests of target fish

Biologgers reveal post-release behavioural impairments of freshwater turtles following interactions with fishing nets

Bycatch, the incidental capture of non-target organisms, occurs in most commercial fisheries. Although immediate bycatch mortality is frequently documented in fisheries, detrimental sub-lethal effects and potential post-release mortality remain largely unknown despite the potential population-level consequences. Turtles are captured as bycatch and their populations are vulnerable to slight increases in adult mortality. In eastern Ontario, turtles are frequently captured as bycatch in a small-scale freshwater commercial fyke-net fishery and, currently, the fate of discarded turtles is unknown. We wished to determine the effect of fyke-net capture on post-release survival and behaviour in eastern musk turtles Sternotherus odoratus and painted turtles Chrysemys picta. We used biologgers equipped with tri-axial acceleration, depth and temperature sensors to document locomotor activity, vertical distribution, and temperature use of entrapped (exposed to forced submergence for 4 h) and control turtles upon release. Overall dynamic body acceleration was used as a measure of post-release activity for the first hour, first 6 h, and first 48 h. Post-release mortality was not detected. Turtles subjected to entrapment exhibited lower activity during the first 6 h following release, and their vertical distribution and temperature use differed in the first 2 h following release, but these effects disappeared after 48 h, suggesting turtles have the ability to recover. Quantifying the post-release mortality and sub-lethal effects of entrapment is important for estimating the population effects associated with bycatch