Certain fox species plunge-dive into snow to catch prey, a hunting mechanism called mousing. Red foxes (Vulpes vulpes) and arctic foxes (Vulpes lagopus) can dive into snow at speeds ranging between 2 and 4 m/s. In new research, scientists at Cornell University found that the elongated snout with higher curvature generates less impact force when it penetrates the snow, reducing the possibility of injury during impact. This skull shape also allows foxes to reach deeper into the snow, providing an advantage for catching small rodents located at greater depths. As a result, the authors predict that red and arctic foxes living in snow-covered areas will have a higher hunting success rate when mousing in snow.
Red and arctic foxes dive into snow to catch prey, a behavior known as mousing.
These foxes can identify the location of animals under several feet of snow through their exceptional sensitivity to rustling noises, which have the peak in 2 to 10 kHz frequencies.
When foxes detect prey location and swiftly leap into snow at speeds of 2 to 4 m/s, they catch their prey completely by surprise.
Previous studies explored this mousing behavior in terms of the diving mechanism and success rate.
Red foxes tend to jump in a north-easterly direction, and the success rate of hunts was much higher when the foxes jumped in this direction, in comparison to all other directions, suggesting that foxes use the Earth’s magnetic field to hunt.
However, the mechanical aspects of snow diving, which are also critical to hunting success, are not well understood.
“The fox’s sharp snout doesn’t significantly compress the snow, it penetrates it without much resistance,” said Professor Sunghwan Jung, a researcher in the Department of Biological and Environmental Engineering at Cornell University.
In the study, Professor Jung and colleagues scanned skulls of red and arctic foxes as well as of lynx and puma skulls.
They 3D-printed the skulls and attached each to a sensor that…
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