28 de marzo de 2024

Walking gaits in Cervidae: all species of deer semi cross-walk, as opposed to ambling

INTRODUCTION

All ruminants walk with subtle gaits, rather awkward to describe.

In an amble, the hind foot is lifted only after the opposite fore is placed.

By contrast, in a semi cross-walk, the hind foot is lifted before the opposite fore is placed.

The footfall-sequence, in reality, varies along a continuum, rather than dichotomously.

However the distinction between amble and semi cross-walk is significant because it potentially affects the balance/stability of the locomotion, as follows:

  • in an amble, there is a moment in which two feet are off the ground on the same side (left or right) - which is relatively unstable because it is conducive to tipping to one side. whereas
  • in a cross-walk (including a semi cross-walk), the two feet off the ground are on different sides, viz. left fore with right hind, or right fore with left hind - which is relatively stable because it maintains diagonal propping.

CERVUS

Cervus elaphus

semi cross-walking:

https://www.freepik.com/premium-photo/red-deer-cervus-elaphus-walking-green-meadow-summertime-nature-wild-hind-marching-open-grassland-summer-female-animal-going-pasture_24217519.htm

https://www.pond5.com/stock-footage/item/85266360-hd-slow-motion-young-stag-red-deer-cervus-elaphus-walking

cross-walking:

https://www.dreamstime.com/red-deer-hind-crossing-stream-water-close-up-winter-image138050863

Cervus elaphus and Cervus canadensis walking gait in masculine display is cross-walk, not amble

https://www.shutterstock.com/image-photo/red-deer-rutting-season-737170840

https://www.shutterstock.com/video/clip-1017907225-wild-red-deer-stag-walking-bright-morning

Cervus canadensis

https://stock.adobe.com/es/images/wild-bull-elk-or-wapiti-walking-through-tall-frost-covered-grass-at-forest-s-edge-jasper-national-park-alberta-canada-cervus-canadensis/122577689

https://www.dreamstime.com/grand-teton-national-park-wy-usa-september-close-up-bull-elk-cervus-canadensis-walking-across-road-traffic-stopped-image296347398

Something approaching an amble in Cervus canadensis:

https://www.alamy.com/stock-photo-wapiti-elk-cervus-elaphus-canadensis-cervus-canadensis-rutting-bull-76021844.html

DAMA

RUCERVUS

Rucervus duvaucelii branderi

a particularly clear illustration of semi cross-walking: https://www.youtube.com/watch?v=EBigKO906QY

RUSA

AXIS

ODOCOILEUS

ALCES

Alces alces

https://www.youtube.com/watch?v=VUVBr_jDBcQ

DISCUSSION

I have found that - in contrast to bovids (Bovidae) - there is a surprising consistency in the walking gaits of deer (Cervidae).

In bovids, the tendency is that cover-dependent species semi cross-walk, whereas 'plains game' amble.

For example:
-cover-dependent bovid: https://www.istockphoto.com/video/kudu-walking-gm472607841-9062520

  • 'plains game' bovid:

This is behaviourally and ecologically correlated, as follows:

  • Cover-dependent bovids tend to be nocturnal, solitary, and camouflage-coloured, with eyes facing somewhat forward.
  • By contrast, 'plains game' are adapted to living in the open, with diurnal habits, gregariousness, conspicuous colouration, and eyes so far on the sides of the head that they can scan behind and in front at the same time.

The pronghorn (Antilocapra americana) belongs to a different family, viz. Antilocapridae. It conforms to the 'plains game' category, and ambles accordingly (https://es.123rf.com/photo_30436381_pronghorn-antelope-p%C3%A9rez.html).

Impalas (Aepycerotini) are a particularly interesting tribe of bovids, combining a superficially deer-like appearance with multifaceted peculiarities (https://www.inaturalist.org/posts/89229-an-index-to-my-posts-about-the-impala-aepyceros-melampus#). They seem cover-dependent, but actually conform in various ways to the 'plains game'.

Accordingly, impalas consistently amble:

The bovid Kobus defassa is comparable in body size and shape to the cervid Cervus canadensis. However, the former sometimes ambles (https://front.motionarray.com/stock-video/common-waterbuck-walking-between-trees-1179445/), whereas the latter barely achieves an amble under any circumstances:

Publicado el marzo 28, 2024 10:26 TARDE por milewski milewski | 1 comentario | Deja un comentario

Assorted literature

Lunt N (2011) The role of small antelopes in ecosystem functioning in Matobos
https://core.ac.uk/download/pdf/145047088.pdf

Schmitt et al. (2016) zebra and giraffe https://academic.oup.com/beheco/article/27/4/1073/1743727?login=false

Publicado el marzo 28, 2024 06:23 TARDE por milewski milewski | 1 comentario | Deja un comentario

27 de marzo de 2024

The mule deer and the damalisk: a paradox of stotters

Both the Rocky Mountain mule deer (Odocoileus hemionus, https://www.inaturalist.org/observations?taxon_id=143865) and damalisks (Damaliscus spp.) stot.

However, the former stots so frequently, consistently, and persistently that there are many illustrations of this demonstrative gait (https://www.youtube.com/watch?v=h8DweS5Z684 and https://www.youtube.com/watch?v=v1_qLKWeXPA) on the Web.

By contrast, the latter stot so seldom that, after trawling through tens of thousands of photos and videos, I have found only one photo (https://stock.adobe.com/images/a-beautiful-topi-antelope-in-the-mara-grassland/62749286?prev_url=detail).

This difference is puzzling.

Indeed, it is doubly puzzling, for the following reasons.

Firstly, there is context.

Stotting - particularly in adults - is a reaction to the arrival of predators, particularly cursorial predators as opposed to ambush predators. The mule deer is usually photographed in situations where the wolf (Canis lupus) has long been exterminated, meaning that the gait is in reaction to the photographer.

By contrast, Damaliscus lunatus (https://www.inaturalist.org/taxa/42276-Damaliscus-lunatus) is often photographed in conservation areas replete with various Carnivora. This means that there is a good chance of photographing it reacting to the arrival of the African hunting dog (Lycaon pictus, https://www.inaturalist.org/taxa/42093-Lycaon-pictus).

Secondly, there is phylogeny.

The mule deer is congeneric - and partly sympatric - with the white-tailed deer (Odocoileus virginianus), which never stots in the strict sense (https://www.inaturalist.org/posts/89498-gaits-and-anti-predator-displays-compared-between-deer-odocoileus-in-north-america-and-impalas-aepyceros-in-africa#).

By contrast, damalisks are related to the red hartebeest (Alcelaphus caama), which has fairly frequently been photographed stotting in adulthood in reaction to human approach ().

In the case of the blesbok and bontebok (Damaliscus pygargus), there are two possible reasons why there are no photos of adults stotting, viz.

  • stotting is naturally absent in this species (possibly because this species is adapted for conservation of energy in nutrient-poor environments), or
  • none of the current populations are subject to the natural regime of predation, particularly w.r.t. the African hunting dog.

In the common impala (Aepyceros melampus), playful rehearsing of the kick-stotting gait is not restricted to juveniles, but occurs also in adult females. This kind of extended playfulness seems not to apply to damalisks.

The above disparities raise a strange thought, as follows.

We have succeeded in saving the bontebok from extinction. The blesbok has actually been restored to a kind of semi-domesticated abundance. However, a certain behaviour is now 'extinct' in these antelopes.

Nowhere is it practicable, today, for these taxa to coexist with the African hunting dog, let alone the full original community of predators. This is unlikely to be remedied in future.

Hence, generation after generation of these damalisks may continue indefinitely without ever expressing a certain natural gait in adults.

If so, one way to think of this plight is as follows.

Imagine a species of acacia which has been saved from extinction only in a few botanical gardens. It happens to have a capacity for spinescence. However, this 'induced defence' is expressed phenotypically only after a certain kind of damage - plus the associated saliva - by a particular herbivore. For practical ('hormonal') reasons, this damage is not emulated artificially.

Thus, generation after generation, the species continues to exist without manifesting something that was, in the original condition, an important part of its nature.

Also see:
https://www.inaturalist.org/posts/89452-stotting#
https://www.inaturalist.org/posts/76632-stotting-in-damaliscus#
https://www.inaturalist.org/posts/70294-one-of-the-few-records-of-stotting-in-hippotragin-bovids#
https://www.inaturalist.org/journal/milewski/80713-the-mara-dolichotis-patagonum-the-most-ungulate-like-rodent-on-earth#
https://www.inaturalist.org/journal/milewski/archives/2022/09#
https://www.inaturalist.org/journal/milewski/90651-illustrations-of-stotting-gaits-in-cervine-deer-cervidae-cervinae#
https://www.inaturalist.org/posts/84799-a-comparison-of-postures-and-gaits-between-two-elands-the-moose-alces-alces-and-the-common-eland-taurotragus-oryx#
https://www.inaturalist.org/posts/49366-locomotory-and-postural-peculiarities-of-impalas-aepyceros-part-1#
https://www.inaturalist.org/posts/71185-the-ten-most-important-differences-between-alcelaphus-cokii-and-alcelaphus-caama#activity_comment_e0236539-4e0b-4861-9530-1120346de1c8#

Publicado el marzo 27, 2024 10:02 TARDE por milewski milewski | 4 comentarios | Deja un comentario

Variation among ungulates in pigmentation of the bare skin of the anus, perineum, udder, inguinal area, and stifle-fold

The perianal/perineal bare skin, ventral to the whitish base of the tail, is somewhat pigmented in the blesbok (https://www.inaturalist.org/observations/69719656).

The following shows that in the vicuna, as in the guanaco, the bare skin on the ventral surface of the tail is pale (depigmented), despite the pigmentation of the perineal skin, around the anus and vulva.

https://www.shutterstock.com/it/image-photo/del-chimborazo-natural-fauna-national-park-2226795159

This contrasts with gazelles, in which the bare skin on the ventral surface of the tail is blackish:

Gazella marica

https://www.shutterstock.com/image-photo/arabian-sand-gazelle-natural-habitat-conservation-1955798821.

https://www.shutterstock.com/image-photo/arabian-sand-gazelle-natural-habitat-conservation-1955798722

https://www.shutterstock.com/image-photo/arabian-sand-gazelle-natural-habitat-conservation-1955798839

Publicado el marzo 27, 2024 05:27 TARDE por milewski milewski | 0 comentarios | Deja un comentario

26 de marzo de 2024

Evolutionary convergence in conspicuous colouration between Arctic fox (Alopex lagopus) and Tibetan wild ass (Equus kiang)

The Arctic fox (Alopex lagopus) and Tibetan wild ass do not live together, but both in a sense inhabit ‘tundra’.

Their patterns of colouration are remarkably similar, considering that one is much smaller-bodied than the other, and a carnivore instead of a herbivore.

In both cases, the pale of the ventral surfaces has extended so high on the sides of the animal that the whole effect is flag-like, i.e. the colouration is conspicuous. The pale has particularly crept up on the hindquarters (between haunch and tail), on the area just posterior to the shoulders, and on the neck (but not the face).

The main difference, apart from the far bushier tail of the fox, seems to be that the Arctic fox retains dark legs/feet, whereas the Tibetan wild ass has pale legs/feet.

http://imgc.allpostersimages.com/images/P-473-488-90/38/3814/V5QIF00Z/posters/tom-walker-male-arctic-fox-in-summer-coloration-on-the-arctic-tundra-alopex-lagopus-alaska-usa.jpg

http://www.skolaiimages.com/stock/albums/alaska/anwr/pbay_arcticfox_002.jpg

http://4.bp.blogspot.com/-QlhXs1WZmro/Tpp0Mxgsa5I/AAAAAAAABUE/fSNLJoxBn6E/s1600/D2H_1524.jpg

http://static.zoonar.com/img/www_repository2/54/38/f4/10_9acc6df8ce0dac743bc0f3cb1d99ab03.jpg

The Arctic fox is coloured for inconspicuousness in winter (all-white) but conspicuousness in summer.

Why would the Arctic fox want to be conspicuous in summer but inconspicuous in winter?

In the case of Arctic/boreal mustelids, the situation may also be more complex than it seems. Several weasel-like species turn white in winter but their summer coats are hard to interpret because they, a bit like the Arctic fox, have conspicuous aspects (e.g. even the winter white coats have dark tail-tips). In the case of the wolverine, the main pattern is a perverse one in which the animal remains dark, so dark that it stands out from a snowy background in what I interpret to be a form of aposematism (which incidentally it shares with the musk-ox in a way).

Stoat (Mustela erminea):
When the white (winter-coat) stoat is in a non-snowy situation, the whole animal stands out in a way consistent with aposematism rather than crypsis; and that the dark distal part of the tail would be unmistakably conspicuous even against an all-snow background. In the summer coat, the animal stands out like a beacon when it adopts a bipedal stance. This, exposing what could be assumed to be a merely countershaded ventral surface but is too abruptly demarcated to conform to that model even when the animal slinks along quadrupedally. 

http://en.wikipedia.org/wiki/Stoat#mediaviewer/File:Mustela_erminea_winter_cropped.jpg

http://en.wikipedia.org/wiki/Stoat#mediaviewer/File:Mustela_erminea_upright.jpg

Publicado el marzo 26, 2024 05:43 MAÑANA por milewski milewski | 0 comentarios | Deja un comentario

25 de marzo de 2024

Reduction of the labial and mandibular vibrissae as part of extreme adaptation to anti-parasite grooming in impalas (Aepyceros), part 2

...continued from https://www.inaturalist.org/journal/milewski/90233-reduction-of-the-labial-and-mandibular-vibrissae-as-part-of-extreme-adaptation-to-anti-parasite-grooming-in-impalas-aepyceros-part-1#

DISCUSSION

It turns out that impalas are peculiar in having reduced vibrissae at the mouth and jaws.

Please compare https://www.dreamstime.com/impala-extreme-close-up-rams-face-base-lyre-shaped-horns-ear-pattern-clearly-visible-image186103431 with 2nd photo in https://animalia.bio/kob.

Nothing in the literature that could have led us to anticipate this discovery.

Of the above, particularly comparable genera, it is Odocoileus that has the longest and most obvious vibrissae. In the case of the mandibular vibrissae, the length is probably up to 10 centimeters.

At the other extreme, Tragelaphus differs less from impalas than do the other genera.

The remaining genera are intermediate. The vibrissae in question seem to be about 3-6 centimeters long, compared to the estimated 2 centimeters of impalas.

Unlike impalas, the cervid genera examined here (Odocoileus, Dama, and Axis) groom by means of the tongue (https://www.youtube.com/watch?v=FKztz7xHxkA and https://www.youtube.com/watch?v=iX6yquvGm7E and https://www.alamy.com/stock-photo-a-whitetail-deer-buck-licking-its-tail-27502925.html?imageid=34A0C1E0-C189-4C7B-9AE1-DA181BA90DC0&p=461&pn=1&searchId=bb2a56afdbfa89699f16c93e8f5304e2&searchtype=0 and https://www.shutterstock.com/video/clip-3792569-fallow-deer-cervus-dama-2-does-grooming and https://www.youtube.com/watch?v=JCIqhvscVEo and https://www.alamy.com/one-fawn-baby-deer-with-white-spots-all-over-licking-its-back-with-a-pink-tongue-on-a-black-background-image353470710.html?imageid=F679AF19-7672-4ABD-B65F-242CFFACC4F1&p=1248493&pn=1&searchId=bb2a56afdbfa89699f16c93e8f5304e2&searchtype=0 and https://www.istockphoto.com/photo/spotted-deer-gm1412756103-462066875?phrase=axis+deer+deer+close+up+macro&searchscope=image%2Cfilm).

I have yet to find information on the method of grooming in Antilope and Kobus.

However, other gazelles use the unspecialised incisiform teeth, not the tongue (https://www.shutterstock.com/video/clip-26357267-beautiful-shot-israeli-mountain-gazelle-licks-his and https://www.shutterstock.com/video/clip-26357333-beautiful-shot-israeli-mountain-gazelle-licks-his and https://www.dreamstime.com/male-springbok-licking-self-grassland-tan-brown-white-male-springbok-small-horns-seen-cleaning-licking-itself-image234306213 and https://www.dreamstime.com/grant-s-gazelle-nanger-granti-grooming-image267309277 and https://www.alamy.com/springbuck-calf-antidorcas-marsupialis-grooming-itself-a-single-young-springbuck-is-born-after-a-6-month-gestation-period-this-gazelle-like-antelo-image335481515.html and https://www.alamy.com/springbok-grooming-himself-in-the-kalagadi-transfrontier-park-south-africa-image333968143.html and https://www.freepik.com/premium-video/panning-shot-revealing-thomson-gazelle-licking-itself-ensuring-it-is-clean_326759 and https://www.shutterstock.com/image-photo/thomson-gazelle-head-turned-back-that-2169074853).

The same method is probably used by Antilope and Kobus, the teeth of which are shown in https://sketchfab.com/3d-models/blackbuck-skull-8f347ff041b24897b33a448cd3461ac6 and https://sketchfab.com/3d-models/waterbuck-skull-dc2abd4f5f5c4f4cb9f90407cfcbf916.

In summary,

  • the bovids in this comparison groom by means of the teeth, whereas the cervids groom by means of the tongue;
  • among the bovids, the teeth are specialised in the order Aepyceros > Tragelaphus > Antilope and Kobus;
  • the differences in the lengths of the labial and mandibular vibrissae correspond approximately with the above distinctions;
  • impalas seem to epitomise a syndrome in which both the dentition (in the form of a toothcomb) and the vibrissae (extremely shortened) are modified; and
  • the significance of this combination of specialisations may be that facilitation of foraging (particularly on shrubs at night) has been traded off for facilitation of anti-parasite grooming.
Publicado el marzo 25, 2024 09:22 TARDE por milewski milewski | 8 comentarios | Deja un comentario

Bovid ruminants tend to have big eyes, whereas cervid ruminants tend to have big noses

Publicado el marzo 25, 2024 02:32 MAÑANA por milewski milewski | 0 comentarios | Deja un comentario

ASSORTED SIGNIFICANT PHOTOS

GAITS

Semi cross-walk in Cephalophus

https://www.shutterstock.com/image-photo/red-forest-duiker-cephalophus-natalensis-known-507532549

https://www.shutterstock.com/image-photo/red-forest-duiker-cephalophus-natalensis-known-511913365

https://www.shutterstock.com/image-photo/red-forest-duiker-cephalophus-natalensis-known-516055774

https://www.shutterstock.com/image-photo/red-forest-duiker-looking-food-fallen-1181611462

in Tragelaphus

https://www.shutterstock.com/image-photo/bushbuck-walking-camp-grounds-straw-thtched-758092663

https://www.shutterstock.com/image-photo/sitatunga-689806066

in Strepsiceros

https://www.shutterstock.com/image-photo/male-kudu-bush-1033182133

https://www.shutterstock.com/image-photo/beautiful-male-kudu-bush-738561217

in Taurotragus oryx

https://www.shutterstock.com/image-photo/common-eland-taurotragus-oryx-southern-antelope-2075742874

Dama dama, stotting:

https://www.facebook.com/watch/?v=10159507797105298

Cervus elaphus trotting

https://www.dreamstime.com/royalty-free-stock-photo-red-deer-close-up-female-running-image32555105

https://photodune.net/item/cautious-red-deer-walking-in-national-park-in-netherlands/39297720

https://www.superstock.com/asset/red-deer-cervus-elaphus-doe-walking-kopenhagen-denmark/4201-22113860

https://stock.adobe.com/images/a-magnificent-red-deer-stag-cervus-elaphus-walking-across-a-field-during-rutting-season/297236372?prev_url=detail

Kobus defassa cross-walking:

https://www.alamy.com/stock-photo-walking-african-waterbuck-in-wild-78946808.html

Antidorcas trotting

https://www.gettyimages.com.au/detail/photo/impala-running-in-front-of-red-sand-dune-royalty-free-image/518337267?phrase=african+impala&adppopup=true

Damaliscus

https://www.shutterstock.com/image-photo/antelopes-african-national-parks-botswana-namibia-2399513767

Alcelaphus lelwel, ambling
https://stock.adobe.com/images/common-tsessebe/687633573?prev_url=detail

Kobus leche, bounding

https://www.alamy.com/stock-image-wild-impala-antelope-in-african-botswana-savannah-165096114.html?imageid=1C64CE3F-5081-435F-BC20-83932DF3C8FE&p=88489&pn=5&searchId=0a04d5b287e14ebe69c5102549dece6a&searchtype=0

RARE ILLUSTRATIONS OF STOTTING

Eudorcas thomsoni

https://www.youtube.com/watch?v=KzP6mDZeM9c

Damaliscus lunatus jimela

https://stock.adobe.com/images/a-beautiful-topi-antelope-in-the-mara-grassland/62749286?prev_url=detail

https://stock.adobe.com/video/topi-mara-baby-kenya-masai-africa-antelope-animal-nature-mother-park-wildlife-mammal-african-safari-national-newborn-wilderness-horns-savannah-beauty-young-background-savanna-n/197236041?prev_url=detail

CAUDAL FLAGGING/HINDQUARTERS BLEEZES

Damaliscus pygargus pygargus

https://www.south-africa-tours-and-travel.com/bontebok.html

Aepyceros petersi:

https://www.shutterstock.com/image-photo/impala-antelope-etosha-national-park-namibia-80239741

Tragelaphus sylvaticus, showing tail:

https://www.shutterstock.com/image-photo/african-bush-buck-antelope-kenya-1043133982

https://www.shutterstock.com/image-photo/young-male-bushbuck-antelope-bush-1579695589

https://www.shutterstock.com/image-photo/bushbok-female-jumping-over-tall-grass-1639521511

PROCAPRA

https://www.shutterstock.com/image-photo/tibetan-gazelle-running-summer-china-82305031

https://www.shutterstock.com/image-photo/tibetan-gazelle-staring-summer-china-82305046

https://www.bing.com/images/search?view=detailV2&ccid=0C6tK5PE&id=D38202E40D7F26D523988924529F4BBDB60A49B4&thid=OIP.0C6tK5PE-svpEzym9bVZmgHaFe&mediaurl=https%3a%2f%2fcdn.greensoft.mn%2fuploads%2fsite%2f812%2fphotos%2fblock%2f20200421103205_acb0724276383efc15d9e3a30cfb7c59.jpg&exph=1419&expw=1920&q=goitered+gazelle+mongolia&simid=608025738727808218&FORM=IRPRST&ck=01436A4D17ACCCA4BA3ABE5B3250D6CE&selectedIndex=87&ajaxhist=0&ajaxserp=0

OUREBIA

https://es.123rf.com/photo_107357836_oriba-ourebia-ourebi-%C3%BAnico-mam%C3%ADfero-sobre-el-c%C3%A9sped-uganda-agosto-de-2018.html?is_plus=1

Nanger granti:

https://www.shutterstock.com/image-photo/homsons-gazelle-eudorcas-thomsonii-one-bestknown-1669190893

Axis porcinus

https://www.alamy.com/stock-photo-female-indian-hog-deer-axis-porcinus-hyelaphus-porcinus-native-from-92876161.html?imageid=7CBB3150-1109-490F-A634-E9D656BD950C&p=172933&pn=1&searchId=84e6be69442cd8dfa2746c3ac8234252&searchtype=0

https://www.alamy.com/stock-photo-male-indian-hog-deer-axis-porcinus-hyelaphus-porcinus-native-from-92876480.html?imageid=9DEBD99A-081C-43AE-A63D-DEEFAFF058F9&p=172933&pn=1&searchId=84e6be69442cd8dfa2746c3ac8234252&searchtype=0

Capreolus capreolus in winter pelage, showing flareable bleeze:

https://www.dreamstime.com/single-deer-standing-peacefully-woodland-looking-over-valley-adult-red-deer-close-up-shot-springtime-scene-deer-standing-image223058709

https://www.dreamstime.com/deer-standing-woodland-looking-over-valley-single-deer-standing-peacefully-woodland-looking-over-valley-adult-red-deer-image223058686

https://www.dreamstime.com/deer-standing-woodland-looking-over-valley-single-deer-standing-peacefully-woodland-looking-over-valley-adult-red-deer-image223058702

Capreolus capreolus in winter pelage, showing flareable ischiopygal bleeze:

https://www.alamy.com/roe-deer-capreolus-capreolus-in-spring-with-dry-grass-blurred-in-background-mother-and-son-wild-animals-in-natural-environemnt-image358119555.html?imageid=EBE04683-F0B1-492C-BA57-46EB4D5FC497&p=324760&pn=1&searchId=84e6be69442cd8dfa2746c3ac8234252&searchtype=0

Odocoileus virginianus, showing flareable pelage at junction of buttocks and haunches:

https://www.alamy.com/stock-photo-a-whitetail-deer-buck-licking-its-tail-27502925.html?imageid=34A0C1E0-C189-4C7B-9AE1-DA181BA90DC0&p=461&pn=1&searchId=bb2a56afdbfa89699f16c93e8f5304e2&searchtype=0

W.r.t. tail of Odocoileus virginianus:

https://www.istockphoto.com/photo/tail-of-a-deer-gm509366741-45788238?phrase=axis+deer+deer+close+up+macro&searchscope=image%2Cfilm

https://www.istockphoto.com/photo/deer-butt-gm172149394-426116?phrase=axis+deer+deer+close+up+macro&searchscope=image%2Cfilm

https://www.shutterstock.com/image-photo/young-deer-looking-away-wildlife-animal-35173795

Odocoileus virginianus

https://www.dreamstime.com/close-up-shot-whitetail-deer-photographed-fall-canaan-valley-state-park-tucker-county-west-virginia-image188533649 and https://www.dreamstime.com/close-up-shot-whitetail-deer-photographed-fall-canaan-valley-state-park-tucker-county-west-virginia-image188533622

Odocoileus hemionus

https://www.shutterstock.com/image-photo/impala-rooibok-mediumsized-antelope-found-eastern-2325295503

Cervus elaphus, showing pattern on hindquarters

https://www.dreamstime.com/close-up-red-deer-roaring-two-hinds-rutting-season-autumn-rut-image126941411

https://www.dreamstime.com/red-deer-stag-hind-autumn-close-up-uk-image126941418

https://www.dreamstime.com/close-up-red-deer-doe-red-deer-doe-backdrop-image122908488

https://www.dreamstime.com/red-deer-doe-backdrop-close-up-image122908437

https://www.dreamstime.com/close-up-red-deer-standing-grass-autumn-close-up-red-deer-standing-grass-autumn-uk-image201810830

Cervus nippon:

https://www.istockphoto.com/photo/bambi-gm176160571-10799375?phrase=axis+deer+deer+close+up+macro&searchscope=image%2Cfilm

Cervus nippon in winter pelage, showing ischiopygal bleeze:

https://www.istockphoto.com/photo/wildlife-scene-of-single-sika-or-spotted-deer-gm1388896481-446378755?phrase=axis+deer+deer+close+up+macro&searchscope=image%2Cfilm

Tail of Dama

https://www.istockphoto.com/photo/single-fallow-deer-buck-dama-standing-in-acid-grassland-gm182926752-14126144?phrase=axis+deer+deer+close+up+macro&searchscope=image%2Cfilm

https://www.dreamstime.com/close-up-fallow-deer-wild-cheshire-close-up-fallow-deer-image249902222

https://www.dreamstime.com/close-up-fallow-deer-wild-cheshire-close-up-fallow-deer-image249902233

https://www.dreamstime.com/close-up-fallow-deer-close-up-fallow-deer-wild-cheshire-image249902211

https://www.dreamstime.com/close-up-fallow-deer-wild-cheshire-image249902236

https://www.dreamstime.com/close-up-fallow-deer-close-up-fallow-deer-wild-cheshire-image249902238

https://www.dreamstime.com/close-up-fallow-deer-wild-cheshire-close-up-fallow-deer-image249902220

https://www.dreamstime.com/close-up-fallow-deer-wild-close-up-fallow-deer-image201124149

https://depositphotos.com/photo/young-roe-deer-graze-edge-forest-rays-sunlight-animals-wild-203302032.html

Antilocapra

https://www.shutterstock.com/image-photo/prong-horned-antelope-walking-across-open-1280602528

Giraffa giraffa angolensis, showing posterior auricular flag and ischial flag

https://www.gettyimages.ie/detail/photo/african-wildlife-giraffes-burchells-zebras-and-royalty-free-image/1265090301?phrase=impala+the+animal&adppopup=true

SUNDRY ASPECTS OF COLOURATION

Damaliscus lunatus jimela ulnar flag

https://www.mediastorehouse.com/ardea-wildlife-pets-environment/danita-delimont/dde-90019521-25396033.html#openModal

Damaliscus pygargus pygargus juvenile

https://stock.adobe.com/images/bontebok-damaliscus-pygargus-south-africa-cape-of-good-hope/325339482?prev_url=detail

Alcelaphus cokii

https://stock.adobe.com/images/damalisque-damaliscus-korrigum-antilope-topi-au-kenya/440915586?prev_url=detail

https://stock.adobe.com/images/3-damalisque-damaliscus-korrigum-antilope-topi-au-kenya/440927549?prev_url=detail

Alcelaphus lichtensteini
antisheen on rump
https://www.shutterstock.com/image-photo/antelopes-african-national-parks-botswana-namibia-2399513165

Alcelaphus lelwel
Excellent illustration of buccal semet
https://stock.adobe.com/images/antilope-damaliscus-in-african/257395045?prev_url=detail

https://www.shutterstock.com/image-photo/antelopes-african-national-parks-botswana-namibia-2399513163

https://www.shutterstock.com/image-photo/antelopes-african-national-parks-botswana-namibia-2399513169

Strepsiceros

https://www.shutterstock.com/image-photo/safari-south-luangwa-valley-zambia-601824314

Taurotragus

https://www.shutterstock.com/image-photo/common-eland-taurotragus-oryx-large-rare-2080151047

Hippotragus

https://www.shutterstock.com/image-photo/roan-antelope-hippotragus-equinus-699426481

https://www.shutterstock.com/image-photo/sable-antelope-hippotragus-niger-rare-magnificent-2214080895

Ourebia

https://www.shutterstock.com/image-photo/oribi-on-liuwa-plains-zambia-africa-207589486

https://www.shutterstock.com/image-photo/oribi-liuwa-plains-national-park-zambia-1730199304

Cervus elaphus

pale accentuation of tine-tips

https://www.istockphoto.com/photo/red-deer-stag-standing-in-the-dead-bracken-in-londons-parks-in-the-uk-gm1405355894-457285138?phrase=axis+deer+deer+close+up+macro&searchscope=image%2Cfilm

https://es.123rf.com/photo_91107070_camino-de-cruce-de-animales-ciervo-en-el-bosque-macho-de-los-ciervos-rojos-animal-adulto-potente-maj.html

Infants

https://www.dreamstime.com/red-deer-calf-standing-meadow-summer-close-up-uk-image237180744

https://www.dreamstime.com/red-deer-calf-standing-meadow-summer-close-up-uk-image237129126

https://www.dreamstime.com/red-deer-calf-standing-meadow-summer-close-up-uk-image227053089

https://www.dreamstime.com/red-deer-calf-standing-meadow-summer-close-up-uk-image227823827

https://www.dreamstime.com/red-deer-calf-standing-meadow-summer-close-up-uk-image227823853

https://www.dreamstime.com/cute-red-deer-calf-standing-close-to-mama-meadow-up-uk-image275838885

Rangifer tarandus

Sweden:
https://www.dreamstime.com/reindeer-road-adult-male-reindeer-huge-antlers-standing-along-road-rangifer-tarandus-image126358242

Giraffa

https://www.shutterstock.com/image-photo/wild-animal-uganda-africa-1509372179

Excellent illustration of posterior auricular flag in Giraffa camelopardalis rothschildi:

https://www.gettyimages.com.au/detail/news-photo/rothschild-species-of-giraffe-wander-in-their-enclosure-at-news-photo/103504036?phrase=southern%20giraffe&adppopup=true

Equus hartmannae

https://www.art.com/products/p42410087052-sa-i10101207/wendy-kaveney-namibia-etosha-national-park-five-zebras-and-giraffes-at-waterhole.htm?upi=PYOSDW0&PODConfigID=4990699&sOrigID=15754

Lynx lynx

https://www.alamy.com/eurasian-lynx-hiding-in-the-forest-small-lynx-hiding-in-the-bushes-cute-lynx-looking-to-the-camera-rare-predator-in-european-nature-image483201157.html?imageid=A75FDD42-4363-4707-A6AC-B421E11F9D74&p=565267&pn=1&searchId=84e6be69442cd8dfa2746c3ac8234252&searchtype=0

SPECIES/SUBSPECIES DISTINCTIONS

Giraffa tippelskirchi thornicrofti

https://www.shutterstock.com/image-photo/giraffe-puku-outback-zambia-23775544

Tragelaphus sylvaticus meneliki:

https://www.shutterstock.com/image-photo/female-rare-endemic-menelik-bushbuck-hiding-1765793552

Tragelaphus scriptus, Pendjari:

https://www.shutterstock.com/image-photo/kewel-trotting-across-road-pendjari-national-1242511357

Caprini, indet.

https://www.shutterstock.com/image-photo/tibetan-gazelles-running-summer-china-115368241

BODY SIZE

Body size in Canis familiaris

https://www.youtube.com/watch?v=jNXKKdTjopw

EYES/ORBITS

https://www.istockphoto.com/photo/marsh-deer-gm485874974-73195999?phrase=axis+deer+deer+close+up+macro&searchscope=image%2Cfilm

Publicado el marzo 25, 2024 12:47 MAÑANA por milewski milewski | 4 comentarios | Deja un comentario

22 de marzo de 2024

21 de marzo de 2024

Adaptive colouration in the puku (Kobus vardoni), an anomalously plain-coloured grazer, part 2

...continued from https://www.inaturalist.org/journal/milewski/91107-adaptive-colouration-in-the-puku-kobus-vardoni-an-anomalously-plain-coloured-grazer-part-1#

INCONSPICUOUS PATTERNS (cont.)

Incipient/residual band at junction of belly/lower flank

This feature, although faint, is consistent among individuals, regardless of sex and age.

https://www.inaturalist.org/observations/37703217

https://www.inaturalist.org/observations/35174260

https://www.inaturalist.org/observations/183532379

https://www.alamy.com/puku-kobus-vardonii-in-south-luangwa-national-park-zambia-puku-south-luangwa-national-park-zambia-image554646007.html?imageid=400C7F4A-C4FC-4712-8446-982514BD414B&p=2184918&pn=1&searchId=660be775941111ad3ff09a1a1eb9c3a4&searchtype=0

https://www.shutterstock.com/image-photo/wildlife-chobe-national-park-botswana-2222434941

https://www.shutterstock.com/image-photo/puku-kobus-vardonii-senganus-male-standing-1624748146

https://www.shutterstock.com/image-photo/male-puku-walking-south-luangwa-2420659305

https://www.shutterstock.com/image-photo/male-puku-154457786

https://www.alamy.com/stock-photo-puku-kobus-vardonii-weibchen-und-jungtier-south-luangwa-national-park-107698960.html?imageid=DEACA7BA-3104-41F5-9F48-5333C521C15C&p=205512&pn=1&searchId=660be775941111ad3ff09a1a1eb9c3a4&searchtype=0

Pale on ventral/anterior surface of neck

https://www.alamy.com/pukus-kobus-vardonii-in-south-luangwa-national-park-zambia-pukus-south-luangwa-national-park-zambia-image554645884.html?imageid=70DB440A-4BA2-4A2A-9C83-4AA4775EDD6D&p=2184918&pn=1&searchId=660be775941111ad3ff09a1a1eb9c3a4&searchtype=0

White on inner surface of upper hindleg

https://www.alamy.com/stock-photo-female-puku-kobus-yardonii-walking-31832363.html?imageid=905185DD-F0A5-4B72-8489-BBF2792AFDF8&p=34420&pn=1&searchId=660be775941111ad3ff09a1a1eb9c3a4&searchtype=0

https://www.shutterstock.com/video/clip-8387497-african-elephants-walking-past-pukus

Plainness on anterior surfaces of legs

https://www.shutterstock.com/image-photo/male-puku-158764706

https://www.shutterstock.com/image-photo/puku-antelope-south-luangwa-national-park-350486321

COMPARISON WITH KOBUS KOB

Nominate subspecies Kobus kob kob

The puku and Kobus kob constitute a 'superspecies', distributed from Senegal to Ethiopia and southwards to Botswana (https://upload.wikimedia.org/wikipedia/commons/8/81/Kobus_kob_distribution.svg and https://upload.wikimedia.org/wikipedia/commons/a/a6/Leefgebied_Puku-Kobus_vardonii.png).

I have shown the colouration of the subspecies Kobus kob kob (https://www.inaturalist.org/journal/milewski/90862-kobus-kob-kob-as-the-west-and-central-african-counterpart-for-the-common-impala-aepyceros-melampus-part-1#).

Comparison with K. k. kob highlights the puzzle of plain colouration in the puku. This is because the former is the smaller-bodied and less associated with open vegetation, yet possesses the more conspicuous features in the form of

  • dark on the anterior surfaces of the legs,
  • dark on the tail-tassel, and dark on the fetlocks (constituting a pedal flag).

Of the conspicuous features seen in K. k. kob, the only one retained in the puku is the posterior auricular flag.

Subspecies Kobus kob thomasi

The following photo-pair shows that the puku is a dull-coloured version of the Uganda kob (particularly superciliary whitish, and dark on anterior surfaces of legs):
https://www.alamy.com/stock-photo-uganda-kob-kobus-kob-thomasi-23820043.html?imageid=B51D937E-CF43-4818-8D6A-3F9904633452&p=4071&pn=1&searchId=bf0df45f6cdd487771c0a27ea33653bf&searchtype=0
versus
https://www.gettyimages.co.uk/detail/photo/puku-luangwa-national-park-zambia-habitat-is-royalty-free-image/128122833?phrase=puku+kobus+vardonii&adppopup=true and https://www.alamy.com/impala-antelope-at-murchison-falls-national-park-safari-reserve-in-uganda-the-pearl-of-africa-image222662810.html?imageid=1F4848EE-8015-4423-A54C-763925F1ECD2&p=370223&pn=1&searchId=4206b8d7157b1538d730f9c70124285d&searchtype=0 and https://www.alamy.com/puku-kobus-vardonii-standing-side-profile-zambia-image179830705.html?imageid=1B0FF3CF-E751-4143-8839-8165628469EA&p=524999&pn=1&searchId=acc709c179443e5d1df94979b0f1c3a2&searchtype=0

https://www.alamy.com/impala-antelope-at-murchison-falls-national-park-safari-reserve-in-uganda-the-pearl-of-africa-image222662790.html?imageid=2F624F51-ECFF-4EBD-870A-6DE913DE0A75&p=370223&pn=1&searchId=4206b8d7157b1538d730f9c70124285d&searchtype=0

Darkness on the tail-tassel is also less well-developed than in the Uganda kob.

https://www.shutterstock.com/image-photo/uganda-kob-muchison-falls-national-park-1533550322

https://www.shutterstock.com/image-photo/some-uganda-kobs-walking-through-green-87766975

https://www.shutterstock.com/image-photo/baby-kob-his-mother-kobus-murchison-1687419769

https://www.shutterstock.com/image-photo/uganda-kob-kobus-thomasi-national-parks-2083558879

https://www.shutterstock.com/image-photo/ugandan-kob-kobus-thomasi-rainy-day-2103703763

https://www.shutterstock.com/image-photo/uganda-kob-kobus-thomasi-national-parks-2015207261

https://www.shutterstock.com/image-photo/beautiful-uganda-kob-front-centre-jackson-1897215655

DISCUSSION

There are various residual/incipient features in the colouration of the puku. These are noteworthy in assessing relationships between the puku and

  • other members of genus Kobus,
  • reduncins (including Redunca),
  • other gregarious bovids, and
  • gregarious cervids in summer pelage.

However, none if these qualifies unambivalently as a conspicuous feature, according to the system of bleezes, flags, and semets ().

The only feature that may perhaps qualify is the pattern on the back-of-ear, consisting of

  • an individually variable dark apex, and
  • a pale (probably sheeny) ventral panel on the proximal part of the posterior surface of the ear pinna.

The dark apex resembles that (https://www.superstock.com/asset/rear-view-impala-female-head-aepyceros-melampus-nakuru-national-park/1566-1419927) of the common impala (Aepyceros melampus), but is

  • not as clear and consistent, and
  • somewhat sexually dimorphic, as opposed to monomorphic in the common impala.

The following exceptionally fortunate photo (https://www.gettyimages.co.uk/detail/photo/pukus-impalas-royalty-free-image/560130395?phrase=puku+kobus+vardonii&adppopup=true) shows clearly the evolutionary convergence in the posterior auricular flags of the puku and the common impala.

The pale panel resembles - but is less well-developed than - those in various cervids, e.g. the sika deer (https://www.istockphoto.com/photo/rear-view-of-a-sika-deer-resting-in-an-animal-farm-gm1729392605-541626097?searchscope=image%2Cfilm and https://www.istockphoto.com/photo/close-up-of-fallow-deer-head-gm498401388-79628877?phrase=axis+deer+deer+close+up+macro&searchscope=image%2Cfilm and https://www.dreamstime.com/close-up-head-female-deer-garden-close-up-head-female-deer-garden-image288507716).

The partial loss of the dark/pale contrast on the back-of-ear in mature males is consistent with similarly subtle sexual dimorphism in

The maximum case for conspicuousness of the pattern on the hindquarters can be seen in https://tandemstock.com/assets/63532549.

The inconspicuousness of the tail of the puku is consistent with that in all other reduncins.

The tail in genus Kobus is possibly less conspicuous than in any other genus of gregarious bovids.

The incipient/residual band at the junction of belly and lower flanks seems convergent with a feature in e.g.

This feature, however faint, is puzzling because it seems to undermine the countershading (https://en.wikipedia.org/wiki/Countershading) that is part of cryptic colouration (https://www.alamy.com/stock-photo/female-puku.html?sortBy=relevant and https://www.shutterstock.com/image-photo/solitary-male-puku-antelope-kobus-vardonii-1085192054).

Therefore, the adaptive significance of the darkish belly/flank-band - whether dark in other ruminants or faint as in the puku - remains to be explained.

The puku has lost the pedal flag seen in Kobus kob (https://www.alamy.com/impala-antelope-at-murchison-falls-national-park-safari-reserve-in-uganda-the-pearl-of-africa-image222662810.html?imageid=1F4848EE-8015-4423-A54C-763925F1ECD2&p=370223&pn=1&searchId=bf0df45f6cdd487771c0a27ea33653bf&searchtype=0).

Publicado el marzo 21, 2024 02:45 MAÑANA por milewski milewski | 82 comentarios | Deja un comentario