Has the post-withers mane-tuft of Hippotragus evolved in mimicry of oxpeckers (Buphagus)? part 1

@tonyrebelo @jeremygilmore @beartracker @paradoxornithidae @dejong @zarek @matthewinabinett @christiaan_viljoen @henrydelange @douglasriverside @tandala @oviscanadensis_connerties @maxallen @michalsloviak @jwidness @davidbygott @ludwig_muller @ptexis @botswanabugs @aguilita @marcelo_aranda @bobby23 @jakob @dinofelis @capracornelius @pmeisenheimer @brenainn @nyoni-pete @richardgill @i_c_riddell @koenbetjes @joseph103 @elisebakker @nickleggatt @lallen

Here are introductory images: https://wall.alphacoders.com/big.php?i=1165392 and https://www.robertharding.com/preview/741-2722/roan-antelope-two-oxpeckers-busanga-plains-kafue-national/.

This is the anatomical location of the withers: https://horse-pros.com/5478/horse-anatomy-withers.

Hippotragus spp. (https://www.inaturalist.org/observations?place_id=any&taxon_id=42331&view=species) are attractive to oxpeckers (Buphagus spp., https://www.inaturalist.org/observations?place_id=any&taxon_id=46&view=species and https://www.youtube.com/watch?v=fhuRR9Sg6l4).

It is obvious that these birds often perch just posterior to the withers (https://www.inaturalist.org/observations/5538629 and https://www.inaturalist.org/observations/34841340 and https://www.inaturalist.org/observations/57000034 and https://www.inaturalist.org/observations/32316511 and https://www.inaturalist.org/photos/29361796 and https://www.inaturalist.org/observations/148842553 and https://www.inaturalist.org/observations/17943594 and https://www.tripadvisor.com/LocationPhotoDirectLink-g1966913-d4491602-i276786359-Chelinda_Lodge-Nyika_National_Park_Northern_Region.html and https://stock.adobe.com/images/antilope-rouanne-hippotragus-equinus/430052750?prev_url=detail).

However, here is something odd.

In the following of Hippotragus equinus, how many individuals are perching just posterior to the withers? (https://www.inaturalist.org/observations/188890271).

The answer is two. So, what is the third object?

The answer is: a special tuft of the mane, which seems to have evolved to attract oxpeckers - somewhat like a decoy on a pond attracting ducks - in this genus of hippotragin bovids.

Now, please closely examine the following (https://www.inaturalist.org/observations/67077421). What do you see: bird(s), or mane-tuft(s)?

How about the following (https://www.inaturalist.org/observations/34374918 and https://www.inaturalist.org/observations/1837040)?

HIPPOTRAGUS EQUINUS (https://stock.adobe.com/images/pferdeantilopen-in-der-ebene-des-chobe-national-parks-in-der-nahe-von-savuti-botswana/243454629?prev_url=detail)

The mane in H. equinus is

The post-withers mane-tuft grows so promptly that it rivals the horns in length in small juveniles (https://www.inaturalist.org/observations/17941075 and https://www.inaturalist.org/observations/6793163 and https://www.inaturalist.org/observations/6442592).

The following shows the post-withers mane-tuft from behind: https://www.alamy.com/stock-photo-african-roan-antelope-calf-hippotragus-equinus-149312880.html?imageid=9AE78C2E-6D4B-4344-B1CE-7CB589235CCA&p=172933&pn=1&searchId=5b7e805efde1b320f1fde4bd1bddb9a3&searchtype=0 and https://stock.adobe.com/images/antilope-rouanne-hippotragus-equinus/430052709?prev_url=detail.

The West African subspecies, Hippotragus equinus koba, is extralimital to one of the two spp. of oxpecker, namely Buphagus erythrorhynchus (https://en.wikipedia.org/wiki/Yellow-billed_oxpecker#/media/File:Buphagus_africanus_map.svg and https://en.wikipedia.org/wiki/Red-billed_oxpecker#/media/File:Buphagus_erythrorhynchus_map.svg).

In this subspecies, the post-withers mane-tuft may be hardly noticeable in adults (https://www.inaturalist.org/observations/34105019 and https://www.inaturalist.org/observations/29326406 and https://www.inaturalist.org/observations/25801218 and https://www.inaturalist.org/observations/98860520 and https://www.inaturalist.org/observations/16027979).

However, it remains present (https://www.inaturalist.org/observations/5280584 and https://www.inaturalist.org/observations/6443409 and https://www.inaturalist.org/observations/6562117 and https://www.inaturalist.org/observations/6183580).

HIPPOTRAGUS NIGER

Hippotragus niger also shows a post-withers mane-tuft (https://www.inaturalist.org/observations/7026088 and https://www.mediastorehouse.com/flpa/sable-antelope-hippotragus-niger-adult-male-6543329.html and https://www.inaturalist.org/observations/164414284 and https://www.inaturalist.org/observations/60429397).

The following (https://stock.adobe.com/images/rappenantilope/33673336?prev_url=detail) shows the size of the post-withers mane-tuft relative to Buphagus erythrorhynchus, the smaller-bodied of the two oxpeckers.

However, the feature in question is less discrete than in H. equinus.

This is mainly because, in H. niger, the mane is

ONTOGENY

In H. niger, as in H. equinus, the mane - including the tuft in question - is extremely precocial (https://stock.adobe.com/images/sable-antelope-portrait/45304064?prev_url=detail and https://stock.adobe.com/images/the-sable-antelope-hippotragus-niger/65016549?prev_url=detail).

Infants of H. niger:

https://www.alamy.com/sable-antelope-hippotragus-nigeryoung-calf-south-africa-image181670081.html?imageid=28EAE029-B0E3-42DA-BF33-817622ABF79C&p=738474&pn=7&searchId=2e53d2ed5b881c2af6863ceb6110b704&searchtype=0

https://www.inaturalist.org/observations/134842522

Juveniles of H. niger:

https://stock.adobe.com/images/sable-antelope/249830413?prev_url=detail and

https://stock.adobe.com/images/portrait-of-a-female-sable-antelope-hippotragus-niger-okapuka-ranch-namibia/641134322?prev_url=detail).

A noteworthy aspect of the development of the mane in H. niger is that

This differentiation by means of pigmentation, as opposed to an actual gap in the mane, may apply even to adult males (https://stock.adobe.com/images/small-group-of-mature-sable-antelope-on-a-farm-in-south-africa/143805504?prev_url=detail).

POSTURE

The post-withers mane-tuft (or dark pigmentation to the same effect) remains prominent despite the lowering of the neck in foraging.

The anatomical position thus potentially enhances the value of this feature in attracting oxpeckers.

This applies to both spp. of Hippotragus, as shown in the following:

ADDITIONAL PHOTOS OF THE POST-WITHERS MANE-TUFT: HIPPOTRAGUS EQUINUS

https://www.robertharding.com/preview/741-2719/roan-antelope-busanga-plains-kafue-national-park-zambia/

https://www.dreamstime.com/stock-photo-roan-antelope-portrait-savanna-southern-africa-image75288830

second photo in https://www.inaturalist.org/observations/174496393

https://www.inaturalist.org/observations/173418588

https://www.inaturalist.org/observations/173418589

https://www.inaturalist.org/observations/34841465

https://www.inaturalist.org/observations/27642639

https://www.inaturalist.org/observations/25684392

https://www.inaturalist.org/observations/24195924

https://www.inaturalist.org/observations/124729794

https://www.inaturalist.org/observations/101392151

https://www.inaturalist.org/observations/59295257

https://www.inaturalist.org/observations/19417570

https://www.inaturalist.org/observations/19128427

https://www.inaturalist.org/observations/9355801

ADDITIONAL PHOTOS OF THE POST-WITHERS MANE-TUFT: HIPPOTRAGUS NIGER

https://www.inaturalist.org/observations/72397302

https://www.inaturalist.org/observations/42159995

https://www.mediastorehouse.com/ardea-wildlife-pets-environment/common-sable-antelope-male-female-1305709.html

https://www.gettyimages.ae/detail/photo/sable-antelope-royalty-free-image/622152400?adppopup=true

https://www.gettyimages.ae/detail/photo/sable-antelope-royalty-free-image/988024350?adppopup=true

https://www.dreamstime.com/sable-antelope-walking-plains-africa-herd-elephant-waterhole-background-hwange-national-park-zimbabwe-image131746669

https://www.krugerpark.co.za/africa_sable.html

https://howieswildlifeimages.files.wordpress.com/2017/03/20151014-d4s_4558.jpg

https://www.flickr.com/photos/154131356@N07/51715923933/in/pool-wildlife_unlimited/

https://www.flickr.com/photos/154131356@N07/51716323674/in/pool-wildlife_unlimited/

https://www.inaturalist.org/observations/187595353

https://www.inaturalist.org/observations/184871699

https://www.inaturalist.org/observations/183155583

https://www.inaturalist.org/observations/139965882

https://www.inaturalist.org/observations/133373188

https://www.inaturalist.org/observations/104347723

https://www.inaturalist.org/observations/21313316

https://www.inaturalist.org/observations/14355100

https://www.inaturalist.org/observations/164414284

https://www.inaturalist.org/observations/108545995

https://www.inaturalist.org/observations/4608441

https://www.inaturalist.org/observations/107512367

https://www.inaturalist.org/observations/7026088

to be continued in https://www.inaturalist.org/journal/milewski/88098-has-the-post-withers-mane-tuft-of-hippotragus-evolved-in-mimicry-of-oxpeckers-buphagus-part-2#...

Publicado el diciembre 25, 2023 06:29 MAÑANA por milewski milewski

Comentarios

Nice illustration of conspicuousness of facial colouration in Hippotragus equinus:

https://www.inaturalist.org/observations/187648092

Publicado por milewski hace 7 meses

Illustration of Ptilostomus afer (https://www.inaturalist.org/taxa/8371-Ptilostomus-afer) perched just posterior to the withers on Hippotragus equinus:

https://www.inaturalist.org/observations/34206847

Publicado por milewski hace 7 meses

Shift

Ear pinna in Taurotragus oryx:

https://www.inaturalist.org/observations/70512529

Publicado por milewski hace 7 meses

Shift

Ischiopygal bleeze in winter coat of Capreolus capreolus:

https://www.flickr.com/photos/doorsafe2028/51697858111/in/pool-wildlife_unlimited/

Publicado por milewski hace 7 meses

REFERENCES ON OXPECKERS

https://scholar.ufs.ac.za/server/api/core/bitstreams/dfbf4cb6-fd63-4dda-953c-5b57f083d702/content

https://link.springer.com/article/10.1023/A:1018439614008

https://repository.up.ac.za/bitstream/handle/2263/42377/37stutterheim1988.pdf?sequence=1&isAllowed=y#:~:text=It%20can%2C%20therefore%2C%20be%20concluded,oxpeckers%20under%20similar%20cir%2D%20cumstances.

https://pubmed.ncbi.nlm.nih.gov/3194119/

http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0075-64582015000100020

https://www.researchgate.net/figure/Host-preferences-of-Red-billed-and-Yellow-billed-Oxpeckers-from-both-Skukuza-and_fig1_284912797

https://www.oiseaux-birds.com/card-yellow-billed-oxpecker.html

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6832191/

https://academic.oup.com/beheco/article/11/2/154/204658

https://www.sciencedirect.com/science/article/abs/pii/S0003347299912654

https://www.sabisabi.com/discover/wild-facts/redbilled-oxpeckers

https://planetofbirds.com/oxpeckers-buphagidae

https://watermark.silverchair.com/110154.pdf?token=AQECAHi208BE49Ooan9kkhW_Ercy7Dm3ZL_9Cf3qfKAc485ysgAAA1UwggNRBgkqhkiG9w0BBwagggNCMIIDPgIBADCCAzcGCSqGSIb3DQEHATAeBglghkgBZQMEAS4wEQQM7wNFChy6Eg-0-ECFAgEQgIIDCJTcDew8aDa4MElqhNLjHGZqnMlQ17_KXipjP7aFnEDfdKNVBrvedRvynlSks7w7lhEGgeWow2g4YIPH7gn28ToAjorfbk_EFZUZ-_eAtzsdVq5tC002kPMb46xm3BjoPv2TjK4AuAtmZbw4JQyKZwJFeI1_rSFzct6oqgBM2hQqFAccpHXy4vHdj4kyuWVsqXXFBGPpVa-HiS6DBMwWwhC4628V6Nn8yKy_IWbp-4yWawHeL1VJ-dQ-pio50S75NXYpsP1xh802A9ehlN2NOK2U7yCiopgmajaoYt1fAdsUYlJ3PPsqfxQJTEpDF6-Q06eM0FCDrKBzxE9oz-LAnlklCf3ABbcfwOEzcSt3o4aTHo2v8glMAeAUDgE85nZLE2XIfcxsppyDvMAtRpyr8JHYCPK71bSS8OXeOkZMktC4A6NXMBJSPlSxh5smH9rU3pPw_izT5gIMu8mNJ5ahl2r_N6XdVSWF1WMc5jawLOOyUI4OHhQbNIp3pBSrGy0LrGQCy7KrHwj1gt4zWLGdYnHpGIDBSRh7YUf_3Nr6zqe5TDgUxYYXj2n9KMFLVIjppaGGWfoy4ch_p2ZO8LYOCMNml1zxpALZm8Z249Gufel1h9er4WG0fNhIuux75N_G3APa8sEnfGnua2cn1V0-XHKQmaLmfIq-l_AZGjygHj6jf_wCChPjUhBsTVAxtkM27fa8hlfqnlj94N6wEvtm6cpl_lPKS57SjBeIqVIlAQzeeQwJ0RIjIKIAsYyAc0hr3-xLpX-Cs3VVRI2gzV3ceUJHM0khzmLxPEuBhHkU1bvuGbs5HZfOddVn3_OmvfUk6Jrh3RzwzVr8oRO07nXEWTJUGZ-X8g1M6bltXmufRjPCHl-yBSkjForxsK0EASw5MsPCQu2BK8qcUnQyJ1Z0RyLLLcph7hhR9jHFKH_6W53n9OjSI86klKWnuBGsfTjI2EXXFAlvoadzTfk9zmSoc1N5Wy3J6So_ax5sfpcz8o1rtIl3a6hJx3XXuhp_0_VkycEo1mKKUZ32

Publicado por milewski hace 7 meses

Fully mature male Hippotragus niger, performing what seems to be a proud-trot (a form of stotting):

https://stock.adobe.com/search?k=sable+antelope&asset_id=364903287

https://stock.adobe.com/images/sable-antelope/364903287?prev_url=detail

Publicado por milewski hace 7 meses

The following shows the appearance of the post-withers mane-tuft of Hippotragus niger niger at distance, in a group of females and juveniles:

https://www.dreamstime.com/stock-photo-sable-antelope-kruger-national-park-south-africa-specie-hippotragus-niger-family-bovidae-image96303408

Publicado por milewski hace 7 meses

Please scroll to the tenth photo in https://fossilrim.org/blog/mclachlan-details-roan-antelope-at-fossil-rim/, for an illustration of the wide gape of Hippotragus equinus.

Publicado por milewski hace 7 meses

HIPPOTRAGUS LEUCOPHAEUS

It is noteworthy that the extinct congener, Hippotragus leucophaeus, had a poorly-developed mane (https://en.wikipedia.org/wiki/Bluebuck).

The post-withers mane-tuft was presumably absent.

The relevance is that H. leucophaeus occurred in South Africa (https://en.wikipedia.org/wiki/Bluebuck#/media/File:Distribution_of_blue,_sable,_and_roan_antelope_in_southern_Africa.jpeg), where its habitat was mainly extralimital to both spp. of Buphagus (https://planetofbirds.com/oxpeckers-buphagidae).

Publicado por milewski hace 7 meses

https://www.alamy.com/female-sable-antelopes-drinking-and-watching-out-in-malawi-image351429949.html

https://www.alamy.com/stock-photo-male-sable-antelope-drinking-95715906.html?imageid=6E8F5E5A-80BE-43CA-B8C1-DB747AF29163&p=161494&pn=1&searchId=656c0bb897f8c1681a73b120e14ec310&searchtype=0

https://www.alamy.com/stock-photo--75688233.html?imageid=BE1C7A4A-0B93-4727-91C3-1BD3BA912749&p=20852&pn=1&searchId=656c0bb897f8c1681a73b120e14ec310&searchtype=0

https://www.alamy.com/stock-photo--75688217.html?imageid=9FCC0DAF-85D8-4809-B159-9FE48BF656B2&p=20852&pn=1&searchId=656c0bb897f8c1681a73b120e14ec310&searchtype=0

https://www.shutterstock.com/image-photo/big-sable-bull-wild-spring-time-2392340965

https://www.shutterstock.com/image-photo/young-sable-bull-walking-side-view-2033376728

https://stock.adobe.com/images/sable-antelope-hippotragus-niger-also-known-as-the-black-ante/86684903?prev_url=detail

https://stock.adobe.com/images/sable-antelope-hippotragus-niger/85341670?prev_url=detail

https://stock.adobe.com/images/sable-antelope-hippotragus-niger-kruger-national-park/113100420?prev_url=detail

https://stock.adobe.com/images/sable-antelope-in-the-grass-with-trees/400668182?prev_url=detail

https://stock.adobe.com/images/sable-antelope/61695756?prev_url=detail

https://stock.adobe.com/images/a-female-sable-antelope-standing-while-being-watchful-of-it-s-surroundings/595200385?prev_url=detail

https://stock.adobe.com/images/elegant-fulll-frame-side-profile-of-a-male-sable-antelope-standing-in-the-bush-in-hwange-zimbabwe/172592829?prev_url=detail

https://www.gettyimages.ae/detail/news-photo/sable-antelope-khwai-concession-okavango-delta-botswana-news-photo/1487609950?adppopup=true

https://www.gettyimages.ae/detail/photo/sable-antilope-chobe-national-park-royalty-free-image/1271308527?phrase=sable+antelope&adppopup=true

https://www.dreamstime.com/royalty-free-stock-photography-sable-antelope-image20725827

Publicado por milewski hace 7 meses

The following video-clip (https://stock.adobe.com/search?k=%22sable+antelope%22&asset_id=321049941) shows a juvenile female individual of Hippotragus niger niger, with horns somewhat longer than the ear pinnae, grazing.

Clearly visible is the post-withers mane-tuft, which - together with the rest of the well-developed mane - is fully dark.

Publicado por milewski hace 7 meses

Fully-developed facial colouration in mature female of Hippotragus niger niger:

https://stock.adobe.com/images/rappenantilope/677630611?prev_url=detail

Publicado por milewski hace 7 meses

Shift

Particularly clear illustration of the flesh-coloured bare skin of the perineum in Taurotragus oryx:

https://stock.adobe.com/images/sable-antilope-calf/53553097?prev_url=detail

Publicado por milewski hace 7 meses
Publicado por milewski hace 7 meses

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