Walking gaits in Cervidae: deer tend to cross-walk, as opposed to the ambling typical of many bovids, part 2: Odocoileinae

https://www.inaturalist.org/observations/196297873

https://www.inaturalist.org/observations/181433160

https://www.inaturalist.org/observations/189329534

https://www.inaturalist.org/observations/101792139

https://www.inaturalist.org/observations/99702464

https://www.inaturalist.org/observations/94002990

https://www.inaturalist.org/observations/19816996

RANGIFER FEET

https://www.inaturalist.org/observations/132865271

https://www.inaturalist.org/observations/89028714

https://www.inaturalist.org/observations/7048852

https://www.inaturalist.org/observations/79613624

?stotting in Capreolus

https://www.inaturalist.org/observations/155377849

https://www.inaturalist.org/observations/204904980

https://www.youtube.com/watch?v=-Fym2VsnDhk

@beartracker Would you agree?

The following track (https://www.inaturalist.org/observations/198845735 and https://www.inaturalist.org/observations/197264836 and https://www.inaturalist.org/observations/197305929) of Capreolus capreolus are revealing of the walking gait, as follows.

Firstly, the larger hoofprint is that of the foreleg.

Secondly, a feature of the cross-walk in ruminants is that the hind foot lands in approximately the same place as the fore foot, i.e. there is at least partial superimposition.

In the cross-walk and semi cross-walk, as the hind foot swings forward, the fore foot gives way at the last moment, avoiding collision between hind and fore.

@beartracker

Many thanks for the correction. I agree that the fore is typically the larger, but I thought that perhaps this is reversed in those species with high hindquarters. Perhaps I will find a way to check this...

Cool!

@beartracker

The following pair of photos illustrates a crucial difference between a cross-walk, typical of deer such as Odocoileus hemionus hemionus (https://www.inaturalist.org/observations/107166688), and an amble, typical of 'plains-game' bovids such as Aepyceros melampus (https://stock.adobe.com/images/male-impala-side-view-species-aepyceros-melampus-the-common-african-antelope-of-kruger-national-park-in-south-africa-c/240572540).

Please focus on the fore and hind legs on the right-hand side of the figure in each case.

In a cross-walk (here shown in the Rocky Mountain mule deer), the hind foot lands in the track of the fore foot, which gives way just in time to avoid collision (please slow the playback in https://www.youtube.com/watch?v=8XRhlvmAMpk).

(The following show that this is true even for juveniles, despite their proportionately long legs: compare https://www.inaturalist.org/observations/75142123 with https://www.inaturalist.org/observations/36167595.)

By contrast, in an amble (here shown in the common impala), the hind foot lands far ahead of the track of the fore foot, which has given way so early that it has allowed an extended forward-swing of the hind (please slow the playback in https://www.istockphoto.com/video/beautiful-and-graceful-impala-antelope-walking-in-savannah-gm932522106-255537892).

This difference in gaits is significant, because it allows a greater stride-length - and a corresponding advantage in energy-economy - in the amble than in the cross-walk.

Odocoileus walks in a way (= cross-walk) adapted mainly in keeping with cover-dependence/nocturnality, an ability to 'freeze' when alarmed mid-stride, stability on unstable/frozen ground, and a habit of smoothly converting to a trot (https://www.inaturalist.org/observations/55935361) when hastening the walk.

Aepyceros walks in a way (= amble) adapted mainly in keeping with obligate gregariousness, diurnality, an abandonment of 'freezing' and other modes of concealment, reliance on firm ground, and an inability to trot - instead accelerating from walking straight to galloping.

The difference is all the more significant because the two taxa featured here are similar in body size and proportions, and are approximate ecological counterparts on different continents.

What is underappreciated - even by those relatively familiar with gaits - is that the walking gait of the common impala is identical to that of giraffes (Giraffa).

The amble would be what we call an overstep walk. The hind oversteps the front track/foot.

I agree. Odocoileus can 'freeze' with three legs on the ground, which gives them a stable tripod to stand on. They can stay that way longer.

Canines, felines, ungulates. Others can perform that gait too.