A travelling animal can employ various gaits, a word that describes the pattern of movement of limbs during locomotion. A bipedal human might walk, hop, or run, each a different form of propulsion. The transition from one gait to another takes place when the energy it takes for, say, a fast walk begins to exceed that of a slow run. Quadrupeds, such as a horse, deer, or dog often have a wider range of choices which might include: walk, amble, pace, trot, canter, gallop, run, or stot.
A trotting mule deer is in suspension (2011).
A characteristic of some of the faster gaits is a period of suspension: a time when all four feet are off the ground. It seems that the faster the animal moves, the longer the period of suspension: Aerial time matters for speed.
Many rapidly moving quadrupeds exhibit a period of suspension.
Do otters?
A 2002 paper that studied the running energetics of the River Otter noted that:
… the ability to incorporate a period of suspension during high speed running was an important compensatory mechanism for short limbs…. Such an aerial period was not observed in river otters….
An otter family walking; None are in suspension (2015).
It is interesting that the authors of this study did not see a running otter in suspension. I do not know how the paper’s authors motivated the otters to run, yet that motivation clearly wasn’t sufficient to prompt them to excel.
I recently watched two otters in suspension while they were running and the motivation seemed to be purely that of having fun — otters, after all, will be otters.
This running otter is in suspension. It was racing along a dock before making a great leap into the water — rather like a child racing up a diving board before leaping off the end. The first otter was followed by a second that did likewise. It seems that pleasing a researcher isn’t as important to a River Otter as having fun.
Tomfoolery
I commented that we should keep an eye out for male Wild Turkeys in display. It is that time of year. And there they were: not one, but two.
After watching the two toms for a while, it struck me that there was something odd about their behaviour. Each was decked out in its striking courting plumage and there were a number of females in the neighbourhood. Yet, rather than seriously approaching the ladies, the two toms stuck so closely together that they were almost always touching.
Were they more interested in each other than the ladies? Well, sort of. Neither seemed interested in the other sexually, but saw him as competition. It seems to have been a example of
which was memorably stated by Micheal Coreleone in the movie, Godfather, Part II (1974), but which originated in Niccolò Machiavelli’s, The Prince (1513).
The two turkey toms appeared inseparable.
Females were plentiful, but so obsessed were the males with blocking the other’s access, that neither made conquests. It was all rather funny and pathetic.
So the toms wandered away loveless, each presumably pleased the other had been thwarted.
