How do you measure kill rates of small prey (<2kg) for individual predators? We found that both accelerometers and audio recorders are up to the task for Canada lynx. A thread with sample audio clips: 1/n @RDerbyshire7 @akmenzies https://besjournals.onlinelibrary.wiley.com/doi/10.1111/2041-210X.13605

Predators are highly secretive and thus incredibly difficult to study. But knowing what predators are eating and how often they eat each species is critical to monitoring the vital rates of all species. To better monitor wildlife, we need to know what the predators are doing. 2/n

We deployed both @TechnosmartEu accelerometers and TS-market audio recorders (spy mics) on 39 Canada lynx over five winters in the Yukon. During this time we followed their tracks in the snow (>4500 locations) to confirm what they were eating.

The audio recorders captured the sounds of hunting including chases and what prey was being hunted. Here is a lynx stalking and chasing a snowshoe hare, its primary prey, that screams when captured. ***warning: clip includes sounds of death that may be disturbing *** 4/n

The audio gave us vital information on what the lynx were hunting through the vocalizations of prey. Here a lynx chases a red squirrel, it's secondary prey. 5/n

Beyond the unprecedented success we had in capturing hunting behaviour, the audio recorders also captured new insight into social behavior of this ‘solitary’ predator. More research to come on this front in the future. Clip: A lynx calling. 6/n

With accelerometers, by running the classification at a resolution of minutes instead of the typical seconds, we achieved almost perfect accuracy at identifying feeding events on hares. What was lost in resolution was gained in accuracy. 7/n

Both technologies work well on their own, but together can allow for continuous record of hunting behaviour of an elusive predator that consumes small prey. We plan to now use this highly detailed data to unlock the mysteries of the lynx and snowshoe hare cycle. 8/n

Special thanks to @ShadhalaAsheyi for allowing us to complete this work within their tradition territory, and to all the technicians over the past 5 years that helped with the intense field work needed to validate both technologies. 9/9