Do hares ever stot?

I thank @lefebvremax and @beartracker for helpful discussion of this topic.

Various species of ruminants stot (https://whyevolutionistrue.com/2013/01/03/antelope-pronking/ and https://en.wikipedia.org/wiki/Stotting).

This behaviour occurs also in a large-bodied, hare-like rodent, namely Dolichotis (https://www.alamy.com/stock-photo-patagonian-mara-cavy-dolichotis-patagonum-stotting-valdes-peninsula-86749556.html and https://www.youtube.com/watch?v=bHU2RAa_-Vo and https://www.youtube.com/watch?v=e0zSyhkyycA and https://www.alamy.com/patagonian-mara-cavy-dolichotis-patagonum-stotting-valdes-peninsula-chubut-patagonia-argentina-image263028463.html and https://en.wikipedia.org/wiki/Mara_(mammal)).

The nature of stotting is basically as follows. The animal:

  • moves exuberantly, expending energy in a conspicuous and inefficient way, and
  • handicaps itself in its locomotion, as if to show off its individual fitness.

Stotting is clearly a form of self-advertisement. However, questions remain of:

  • whether the demonstration is directed towards members of the same species on one hand, or potential predators on the other, and
  • what message is being sent.

As far as I know, no naturalist has previously claimed that any lagomorph stots, at least in the quadrupedal way. The words 'hare' and 'stot' do not seem to appear in the same sentence, anywhere in the biological literature.

What have been frequently mentioned are 'observation leaps' (https://academic.oup.com/mspecies/article/doi/10.2307/3504151/2600727?login=false and https://www.researchgate.net/publication/348464180_Lagomorpha_Locomotion), in which hares in the act of fleeing intersperse their normal gallop with occasional, particularly high bounds.

Nearly all authors seem to have assumed that 'observation leaps' function not as a form of self-advertisement, but rather as a way of maintaining a clear view of the potential predator.

Therefore, in view of the above:
Establishing that Lepus stots in evolutionary convergence with ruminants and Dolichotis would be something new to science.

At present, the evidence for stotting in hares falls into three categories (besides 'observation leaping', part of the function of which remains questionable), as follows:

  • sundry photos and videos suggesting aberrations from the normal gaits of running, often in uncertain circumstances,
  • clear evidence, in a few large-bodied, ecologically extreme species, of bipedal gaits unknown in other mammals but plausibly interpreted as a form of stotting, and
  • fairly unambivalent self-advertisement in one species, which probably constitutes stotting but has not been labelled as such.

HINTS OF STOTTING IN SUNDRY SPECIES

The following photos and videos suggest subtle forms of stotting. The contexts are unclear, and in some cases may be courtship and rivalry rather than reactions to the approach of potential predators. It is also possible that hares differ from ruminants and Dolichotis in that the bouncing gait occurs not as the animal initially runs but instead as it slows down from a bout of running.

Lepus californicus: https://inaturalist.nz/observations/101996083 and https://inaturalist.nz/observations/64044230

Lepus townsendii: https://www.inaturalist.org/observations/35863227 and https://www.researchgate.net/figure/Startled-white-tailed-jackrabbit-Lepus-townsendii-in-full-flight-in-native-grass-cover-at_fig2_339086542

Lepus timidus: https://www.shutterstock.com/nb/image-photo/mountain-hare-lepus-timidus-known-blue-396645550

Lepus europaeus:
Two gaits suggestive of stotting can be seen from about 4 minutes 30 seconds in https://www.youtube.com/watch?v=ylqBH7iOXl4 and from about 1 min 45 sec in https://www.youtube.com/watch?v=q3JM0hhNOOU.
The following show possible stotting: https://www.inaturalist.org/observations/106614136 and https://upload.wikimedia.org/wikipedia/commons/1/13/Feldhase%2C_Lepus_europaeus_2a.JPG and https://www.agefotostock.com/age/en/details-photo/european-hare-lepus-europaeus-adult-male-running-stotting-back-to-female-in-grass-field-suffolk-england-march/FHR-10512-00774-842 and https://www.alamy.com/european-hare-lepus-europaeus-adult-male-running-stotting-back-to-image61827919.html and https://www.inaturalist.org/observations/73530651 and https://www.inaturalist.org/observations/73202777 and https://www.alamy.com/european-hare-lepus-europeaus-adult-male-running-with-a-bouching-gait-known-as-stotting-over-grassland-suffolk-england-february-image462643335.html.

Lepus does not normally erect its tail in flight. I suspect that stotting in e.g. Lepus europaeus sometimes features both a bouncing action and the swinging of the tail higher than usual (as seen in the first photos in each of https://www.inaturalist.org/observations/106614136 and https://www.inaturalist.org/observations/73202777). This exposes not just the white underside of the tail (which is only partly exposed https://www.istockphoto.com/photo/running-hare-gm467394605-33962244 in normal fleeing gaits in Lepus) but also a white patch of pelage on the buttocks, which is hardly noticeable in the normal action of fleeing.

BIPEDAL LOCOMOTION IN LARGE-BODIED SPECIES, possibly qualifying as stotting

See:

Only a few species of hares use bipedal gaits when fleeing from potential predators (https://www.youtube.com/watch?v=xJoB5gk8riY). It seems reasonable to interpret this as a form of stotting. Lepus arcticus and L. alleni are both unusual for hares by virtue of their large body size and their gregariousness.

In L. arcticus, both hind legs move in synchrony in the bipedal gait. However, the action is different from that in wallabies because the strides are short and rapid, and the body is held upright.

In L. arcticus, there is an additional gait in which only three legs touch the ground (https://animaldiversity.org/accounts/Lepus_arcticus/), in what amounts to a self-imposed, running limp.

APPARENT QUADRUPEDAL STOTTING IN LEPUS CALLOTIS

See Lepus callotis in https://www.inaturalist.org/posts/64011-interspecific-variation-in-flags-as-features-of-adaptive-colouration-in-hares-part-2-other-species-of-semi-arid-north-america#.

This species seems to qualify for stotting in a quadrupedal gait resembling that in ruminants..

Best and Henry (1993) state: "When flushed, L. callotis alternately flashes its white sides while running away from the intruder...Another escape behavior is that of leaping straight upward while extending the hind legs and flashing the white sides. This behavior is seen when the white-sided jackrabbit is startled or alarmed by a predator."

Seemingly relevant is the fact that L. callotis is unusual in its social structure. This species is the only hare known to occur in pairs, with an obvious pair-bond.

DISCUSSION

Much remains to be documented and interpreted with respect to possible stotting in hares.

For example, a detailed review of Lepus timidus (https://www.jstor.org/stable/3504302 and https://www.researchgate.net/publication/275737416_Lepus_timidus) makes no mention of any gaits, despite the wide distribution of this species and its close relationship to L. arcticus.

Not only 'observation leaping' but also bipedal standing at the approach of potential predators (https://www.tandfonline.com/doi/pdf/10.1080/03014220709510074 and https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1439-0310.1993.tb00544.x), when conducted in the open (https://www.gettyimages.com.au/detail/photo/jump-royalty-free-image/89348401?adppopup=true), may make more sense as demonstrations of individual fitness than as ways of keeping a potential pursuer in sight.

Regardless of the poor coverage in the past, what is already clear is the diversity of gaits (plus postures such as demonstrative, bipedal standing) listed above as candidates for stotting.

No species of Lepus stots as frequently/predictably as do certain gazelles, deer, and Dolichotis. However, where hares seem to excel is in the variety of gaits that are candidates for stotting within a single genus. I know of no genus of hoofed mammal or rodent in which such a diversity of potentially self-advertising forms of locomotion occurs.

Posted by milewski milewski, May 23, 2022 00:46

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