...continued from https://www.inaturalist.org/journal/milewski/85734-hippotragin-bovids-in-posteriolateral-view-an-interspecies-comparison-of-adaptive-colouration-part-1#
FOCUSSING ON THE TAIL
In terms of colouration (more particularly, dark/pale contrasts), the part of the tail that confers conspicuousness is
Furthermore, the various species can be categorised as follows, w.r.t. how conspicuous the tail is, in posteriolateral view.
TAIL CONSPICUOUS
TAIL AMBIVALENT BETWEEN CONSPICUOUS AND INCONSPICUOUS
TAIL INCONSPICUOUS
DISCUSSION
A surprising finding in this comparison is how heterogeneous the colouration is among the various species.
Indeed, there is so much variation in the posteriolateral patterns that
It has been proposed, in the past, that O. gazella, O. beisa, and O. callotis all belong to a single, geographically disjunct species. Even today, many regard beisa and callotis as conspecific. However, this study of adaptive colouration has revealed categorical differences, suggesting three distinct species.
Only two of the hippotragin species emerge as possessing unambivalent bleezes in posteriolateral view.
These are
In addition, an argument can be made for a bleeze in A. nasomaculatus in winter coat.
There is one recently extinct species, namely Hippotragus leucophaeus (https://www.nature.com/articles/s41598-020-80142-2).
This seems to have been the plainest-coloured of hippotragins (https://www.pinterest.com.au/pin/afterlife-the-mounted-skin-at-naturalis-leiden-the-netherlands--28288303894067651/ and https://maker-scratchpad-youtube.fandom.com/wiki/Bluebuck?file=Bluebuck.jpg and https://www.alamy.com/bloubok-hippotragus-leucophaeus-with-scale-in-rhineland-size-hippotragus-leucophaeus-bluebuck-draughtsman-robert-jacob-gordon-oct-1777-mar-1786-paper-pen-brush-h-660-mm-w-480-mm-h-260-mm-w-422-mm-h-224-mm-w-421-mm-image472065082.html?imageid=CE54FA6B-7419-4641-BBF7-8FC971D77511&p=1834549&pn=1&searchId=3de7156d478f2302cce398840ed9728d&searchtype=0 and https://www.museumfuernaturkunde.berlin/en/press/press-releases/blue-and-lonesome-rarity-blue-antelopes-museum-collections and https://upload.wikimedia.org/wikipedia/commons/6/66/Bluebuck_by_Allamand%2C_1778.jpg and https://eol.org/media/28755258 and scroll to second photo in https://sportsafield.com/2020/out-of-the-mists-of-time/ and https://www.tumblr.com/thylacine-dreams/167273378400/taxidermy-specimens-of-the-extinct-bluebuck and https://forschungsinfrastruktur.bmbwf.gv.at/en/fi/1-zoologie-mammals_4547).
However, a skin preserved in Paris (https://bioone.org/journals/zoosystema/volume-42/issue-5/zoosystema2020v42a5/The-Paris-Bloubok-Hippotragus-leucophaeus-Pallas-1766-Bovidae-and-its/10.5252/zoosystema2020v42a5.short) suggests that, as in H. equinus,
Furthermore, mature males are recorded as having been whitish overall (https://animals.fandom.com/wiki/Bluebuck).
Therefore, it is plausible that H. leucophaeus was somewhat conspicuous in posteriolateral view, and that - partly and in its own way - it emulated H. niger (sexual dimorphism) and O. leucoryx (overall pallor) in its adaptive colouration.
Comments
https://www.diva-portal.org/smash/get/diva2:1522557/FULLTEXT02.pdf
https://bioone.org/journals/zoosystema/volume-42/issue-5/zoosystema2020v42a5/The-Paris-Bloubok-Hippotragus-leucophaeus-Pallas-1766-Bovidae-and-its/10.5252/zoosystema2020v42a5.short
https://sciencepress.mnhn.fr/en/periodiques/zoosystema/42/5
https://sciencepress.mnhn.fr/sites/default/files/articles/pdf/zoosystema2020v42a5.pdf
https://academic.oup.com/mspecies/article/doi/10.1644/807.1/2600200?login=false
https://sketchfab.com/3d-models/blue-antelope-nhmw-zoo-mamm-st715-0d5170d9339e4d14bc1f0b2abf06111a
https://journals.co.za/doi/pdf/10.10520/AJA00382353_1382
https://bilderreich.de/1499-7663/image-south-african-oryx-horn-namibia.html
https://www.flickr.com/photos/a-to-zphotos/48123319447
https://www.shutterstock.com/image-photo/beisa-oryx-adult-savannah-masai-mara-1614352966
https://www.inaturalist.org/observations/6560853
https://www.inaturalist.org/observations/11028813
https://www.inaturalist.org/observations/138407602
https://www.inaturalist.org/observations/118516432
https://alchetron.com/Fringe-eared-oryx
https://www.gettyimages.co.nz/detail/photo/oryx-royalty-free-image/999554848?adppopup=true
https://animalia.bio/arabian-oryx
https://animalia.bio/arabian-oryx
https://cozamal0tl.tumblr.com/post/698607590964396032/animals-with-hornsantlers-1-the-addax
The following show the difference in conspicuousness, at some distance, between Oryx callotis and Oryx beisa.
Oryx callotis:
https://www.alamy.com/stock-photo-fringed-eared-oryx-oryx-gazella-cullotis-tsavo-east-national-park-53906727.html?imageid=96530659-FC1E-4F68-ACDF-D70A8616500F&p=22059&pn=1&searchId=4f0dd42eb1a3853d476f41d97adf47e2&searchtype=0
https://www.alamy.com/stock-photo-kenya-tsavo-west-national-park-a-herd-of-fringe-eared-oryx-on-the-19323658.html?imageid=14ADB6D4-57CB-48FD-BCB1-95582090CC76&p=37852&pn=1&searchId=4f0dd42eb1a3853d476f41d97adf47e2&searchtype=0
Oryx beisa:
https://www.alamy.com/east-african-oryx-fringe-eared-oryx-oryx-beisa-callotis-samburu-national-image527432.html?imageid=7DE8C0CC-2F21-49D2-8243-75D72A6D351A&p=79697&pn=1&searchId=4f0dd42eb1a3853d476f41d97adf47e2&searchtype=0
https://www.alamy.com/east-african-oryx-fringe-eared-oryx-oryx-beisa-callotis-samburu-national-image527431.html?imageid=DB947F9E-52B5-4A8B-8852-963D6D88F560&p=79697&pn=1&searchId=4f0dd42eb1a3853d476f41d97adf47e2&searchtype=0
@matthewinabinett
Excellent (but mislabelled by implication) photo of Oryx beisa, worth zooming in on:
https://m.facebook.com/arushahuntingsafari/
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