Adaptive radiation of auricular flags in hippotragin bovids: Hippotragus, Oryx, and Addax, part 1

@tonyrebelo @jeremygilmore @beartracker @paradoxornithidae @tandala @oviscanadensis_connerties @davidbygott @dejong @michalsloviak @botswanabugs @matthewinabinett @gigilaidler @ashby2 @simontonge @justinponder2505 @variani18 @capracornelius @jwidness

INTRODUCTION

Everyone knows that hippotragin bovids (https://www.inaturalist.org/observations?place_id=any&taxon_id=846296&view=species) tend to have conspicuous colouration on the face.

However, in previous accounts of hippotragins, the ear pinnae have not been described clearly in a comparative way. This is partly because their appearance tends to be subsumed into that of the head in general.

WHAT IS AN AURICULAR FLAG?

An auricular flag is a pattern of adaptive colouration, on and/or at the base of the ear pinnae, that is bold enough to advertise the animal - at moderate distance from the observer - when the ears, head, or whole figure move.

The assumed function of auricular flags in ungulates is medium-range communication, both intraspecific (social) and with potential predators.

Auricular flags tend to differ from auricular semets mainly

• in scale (auricular semets being small-scale patterns of colouration, noticeable only close-up), and
• in signalling alertness and alarm to predators, as much as communicating emotion/intention intraspecifically.

Auricular semets tend to function as facial expressions: whereas humans use the mouth and eyes/eyebrows, ungulates use the ear pinnae - which are far more mobile than in primates - instead.

By contrast, auricular flags function, at least partly, as 'visual alarm calls' and aids to gregariousness and group-cohesion.

Intrinsic to the definition of auricular flags is that the colouration of the ear pinnae can function in a converse way when the figure, head, and ears are stationary - as, for example, when an individual ungulate 'freezes' in reaction to the arrival of a scanning predator. A given pattern on the ear pinnae can be disruptive enough to aid camouflage when immobile, but bold enough to aid advertisement when the animal divulges its presence by moving (https://www.inaturalist.org/journal/milewski/80254-does-the-greater-kudu-strepsiceros-possess-an-anterior-auricular-flag#).

This ambivalence means that a degree of subjectivity is inevitable in any verdict of whether a given species possesses an auricular flag or not.

In the case of hippotragins, the criteria for auricular flags are additionally complicated, as follows.

Imagine, in a thought-experiment, that the following ear pinnae retain their colouration, while the rest of the head becomes plain-coloured (https://www.inaturalist.org/observations/69314637). Would the auricular pattern not become more noticeable?

So, our approach needs to take account of how the auricular colouration, however stark in itself, has been incorporated/subsumed into the composite colouration of the whole face and head.

Throughout this Post, I heed only dark/pale contrast, not hues.

ANTERIOR VS POSTERIOR AURICULAR FLAGS

Most of the flags that I have discovered in this Post are on the anterior surface (in some cases including the anterior base) of the ear pinna. However, inns few cases, hippotagins also feature posterior auricular flags.

These are described in part 3 (https://www.inaturalist.org/journal/milewski/88277-adaptive-radiation-of-auricular-flags-in-hippotragin-bovids-hippotragus-oryx-and-addax-part-3#).

HIPPOTRAGUS EQUINUS

Factors enhancing conspicuousness of ears:

• elongation (https://stock.adobe.com/images/frontal-close-up-of-roan-antelope-father-and-his-son-hippotragus-equinus/525809784?prev_url=detail)
• pallor (whitish pelage, https://www.inaturalist.org/observations/88291810; bare skin, not usually visible, is flesh-coloured, not pigmented, https://www.inaturalist.org/observations/21834582 and https://www.inaturalist.org/observations/8255165 and https://www.alamy.com/portrait-of-a-male-roan-antelope-hippotragus-equinussouth-africa-image68947753.html?imageid=E479558A-0E2A-47B6-AFC9-D625BC54D2A4&p=3864&pn=1&searchId=d3350f0b953b17636829cec591564ee8&searchtype=0)
• darkness of apical tufts (particularly in juveniles, https://www.alamy.com/africa-tanzania-portrait-of-a-young-roan-antelope-image470730784.html?imageid=75E29B04-135C-4E1E-8958-3B756EFD4B8D&p=16459&pn=5&searchId=5ed1e1ea051df95555f6aaed35fb537c&searchtype=0)
• precociality in size, relative to head and body (https://www.inaturalist.org/observations/179594317 and https://www.inaturalist.org/observations/181196418 and https://www.mediastorehouse.com/flpa/roan-antelope-hippotragus-equinus-calf-6542987.html).

Factors detracting from conspicuousness of ears:

• loss of dark apical tufts in maturity, particularly in males
• distraction by bold pattern on face (https://www.alamy.com/stock-photo-roan-antelope-hippotragus-equinus-is-a-savanna-antelope-found-in-west-47795015.html?imageid=A2F63EDD-8945-4CA6-BD38-7186ABD962D0&p=11592&pn=10&searchId=fef2a329ee21fcc00a29b07a7ffad839&searchtype=0 and https://www.inaturalist.org/observations/81420827 and https://stock.adobe.com/images/roan-antelope-hippotragus-equinus-in-the-grass-mountain-in-the-background-savuti-namibia-africa-animal-savannah-antelope-in-the-nature-habitat-nature-wildlife/556297398?prev_url=detail and https://www.inaturalist.org/observations/17943594).

Overall effect:

Hippotragus equinus qualifies for an auricular flag, particularly in juveniles (https://stock.adobe.com/images/roan-antelope-hippotragus-equinus-savanna-antelope-found-in-west-central-east-and-southern-africa-detail-portrait-of-antelope/266580373?prev_url=detail and https://www.inaturalist.org/observations/151488614 ). The ear pinnae seem partly to function as head-adornments, at a stage of life when the growing horns are still small.

Adult males:
https://www.gettyimages.com.au/detail/photo/roan-antelope-male-and-female-south-africa-royalty-free-image/541054500
https://www.alamy.com/stock-photo-hippotragus-equinus-roan-antelope-30156557.html?imageid=D8C8C064-A826-47E2-BE6E-0A87E1DC8D69&p=87775&pn=1&searchId=5b7e805efde1b320f1fde4bd1bddb9a3&searchtype=0

Adult females:
https://www.gettyimages.com.au/detail/photo/portrait-of-goat-standing-on-field-royalty-free-image/1778473255
https://upload.wikimedia.org/wikipedia/commons/9/96/Roan_antelope_%28Hippotragus_equinus%29.jpg
https://www.africaimagelibrary.com/-/galleries/west-africa/senegal/-/medias/4c631c20-2120-11e0-ba98-f50f3d063bc0-roan-antelope-hippotragus-equinus-reserve-de-bandia-senegal
https://www.agefotostock.com/age/en/details-photo/roan-antelope-hippotragus-equinus-male-portrait-native-to-africa-in-captivity-germany-europe/IBR-2188756
https://www.alamy.com/portrait-of-a-roan-antelope-image469741584.html
https://www.africaimagelibrary.com/-/galleries/west-africa/senegal/-/medias/4c631c20-2120-11e0-ba98-f50f3d063bc0-roan-antelope-hippotragus-equinus-reserve-de-bandia-senegal
https://www.mediastorehouse.com/flpa/roan-antelope-hippotragus-equinus-adult-female-6543535.html
https://www.alamy.com/stock-photo-roan-antelope-55455157.html?imageid=CD887378-42EC-4C4F-B01B-F361AFECD724&p=197940&pn=1&searchId=d3350f0b953b17636829cec591564ee8&searchtype=0
https://www.alamy.com/africa-tanzania-headshot-of-a-roan-antelope-image470730780.html?imageid=981D840E-4309-405D-8E25-E77A66353653&p=16459&pn=1&searchId=d3350f0b953b17636829cec591564ee8&searchtype=0
https://www.alamy.com/roan-hippotragus-equinus-mlilwane-nature-reserve-breeding-programme-eswatini-africa-image432452607.html?imageid=A04CCD6D-C86D-4D8B-96EF-C7D99091336B&p=12455&pn=4&searchId=f4904b3f875d4b7dbcba6638b9b119cf&searchtype=0
https://www.shutterstock.com/image-photo/roan-antelope-499585456

Adolescent males:
https://www.inaturalist.org/observations/150756759
https://www.alamy.com/a-rare-roan-antelope-hippotragus-equinus-in-natural-habitat-mokala-national-park-south-africa-image554287794.html?imageid=10134C95-E91A-4C6C-9E7C-875897EFA232&p=70019&pn=5&searchId=5ed1e1ea051df95555f6aaed35fb537c&searchtype=0

Adolescent females:
https://stock.adobe.com/images/roan-antelope-hippotragus-equinus-savanna-antelope-found-in-west-central-east-and-southern-africa-detail-portrait-of-antelope-head-with-big-ears-and-antlers-wildlife-in-africa/176950256
https://www.inaturalist.org/observations/25801218
https://www.inaturalist.org/observations/168152303

Juvenile males:
https://www.alamy.com/a-close-portrait-of-a-male-roan-antelope-hippotragus-equinus-in-zimbabwes-hwange-national-park-image399151037.html
https://www.alamy.com/a-close-portrait-of-a-male-roan-antelope-hippotragus-equinus-in-zimbabwes-hwange-national-park-image399150259.html

Juvenile females:
https://www.alamy.com/stock-photo-roan-antelope-hippotragus-equinus-kafue-national-park-zambia-11846037.html?imageid=25F7A4C7-4B9D-452B-8921-114C4931035A&p=74587&pn=3&searchId=d47afca96099067b240be3e499db1072&searchtype=0
https://www.dreamstime.com/stock-photo-roan-antelope-portrait-savanna-southern-africa-image75288830
https://www.alamy.com/a-sable-antelope-in-the-african-bush-image432627348.html?imageid=56996DE1-B073-42E1-A741-F5F6303F616D&p=1688452&pn=6&searchId=97540ae770603cf106671452aa5a7a4b&searchtype=0

Small juveniles:
https://www.alamy.com/stock-photo-roan-antelope-hippotragus-equinus-okavango-delta-botswana-wild-13190862.html?imageid=AEB29662-023B-4E83-834B-A49FD352708B&p=9411&pn=2&searchId=96799d31708c29134f49a83c924d2668&searchtype=0
https://www.dreamstime.com/royalty-free-stock-images-roan-antelope-image28234209
https://www.alamy.com/stock-photo-roan-antelope-on-yellow-background-99467758.html?imageid=D018A1A4-6D71-49FA-8FBC-E87CB4CA4355&p=298512&pn=1&searchId=d3350f0b953b17636829cec591564ee8&searchtype=0

Infants:
https://www.alamy.com/stock-photo-head-of-a-foal-of-a-roan-antelope-93550431.html?imageid=D82C61B1-5A0B-4E05-B7CF-7FDBDFA34AE6&p=291400&pn=1&searchId=5b7e805efde1b320f1fde4bd1bddb9a3&searchtype=0
https://es.123rf.com/photo_188099569_frontal-close-up-of-a-young-roan-antelope-hippotragus-equinus.html

HIPPOTRAGUS NIGER

Factors enhancing conspicuousness of ears:

• pallor (whitish pelage and pale bare skin).

(The ear pinnae have dark tips, on such a small scale that their effect is easily overlooked (https://es.123rf.com/photo_47423494_rara-de-ant%C3%ADlope-sable-de-%C3%A1frica-que-mienten-en-la-hierba-seca.html and https://www.gettyimages.ae/detail/photo/portrait-of-deer-standing-on-field-royalty-free-image/1587662681?phrase=sable+antelope&adppopup=true).)

Factors detracting from conspicuousness of ears:

• distraction by bold pattern on face (male: https://www.alamy.com/roan-antelope-hippotragus-equinus-namibia-image60870004.html?imageid=8DC3916B-9E64-4B34-B9EA-E4026BF9104D&p=186329&pn=7&searchId=48c5019063f87c658c767ebd85f25bc9&searchtype=0; female https://www.imageprofessionals.com/en/images/13818069-Sable-antelope-Hippotragus-niger-Khwai-Concession-Okavango-Delta-Botswana-Africa).

Overall effect:
Hippotragus niger fails to qualify for an auricular flag. This is despite the fact that, in mature individuals, the whitish of the front-of-ear contrasts with the blackish extensive over most of the figure.

Another way of putting this is that, in H. niger, the anterior surface of the ear pinnae tends to be subsumed into the overall facial display (https://www.gettyimages.ae/detail/photo/sable-antelope-royalty-free-image/WL003545?phrase=sable+antelope&adppopup=true and https://www.gettyimages.ae/detail/photo/sable-antelope-okapuka-ranch-namibia-africa-royalty-free-image/130887303?phrase=sable+antelope&adppopup=true and https://www.gettyimages.ae/detail/photo/side-view-of-deer-standing-on-field-royalty-free-image/1587662178?phrase=sable+antelope&adppopup=true).

To a lesser degree than in H. equinus, an effect of precociality is noticeable in H. niger. This is owing to slightly exaggerated size of the ear pinnae in juveniles (https://es.123rf.com/photo_41763725_ant%C3%ADlopes-sable-hippotragus-niger-en-el-h%C3%A1bitat-natural-de-%C3%A1frica-del-sur.html).

Adult males:
https://www.gettyimages.ae/detail/photo/male-sable-antelope-willem-pretorius-game-reserve-royalty-free-image/98218707?phrase=sable+antelope&adppopup=true
https://www.shutterstock.com/image-photo/sable-bull-closeup-south-africa-2263557813
https://www.gettyimages.ae/detail/photo/sable-antelope-bull-africa-royalty-free-image/200351165-001?phrase=sable+antelope&adppopup=true

Adult females:
https://steenknarberg.com/billedarkiv/galleries/stockphoto-billedarkiv/roan-antelope-hippotragus-equinus-single
https://www.gettyimages.ae/detail/photo/male-southern-sabel-antelope-side-view-of-deer-royalty-free-image/1383541155
https://es.123rf.com/photo_187507654_sable-antelope-hippotragus-niger-adult-standing-in-forest-south-africa.html

Adolescent female:
https://es.123rf.com/photo_39132163_ant%C3%ADlopes-sable-de-mujeres-hippotragus-niger-en-el-h%C3%A1bitat-natural-%C3%A1frica-del-sur.html

Juvenile female:
https://www.mediastorehouse.com/ardea-wildlife-pets-environment/sable-antelope-young-buck-kruger-national-1308736.html

ORYX DAMMAH

Factors enhancing conspicuousness of ears:

• central darkness (pigmented bare skin, contrasting with pale pelage over rest of ear pinna).

Factors detracting from conspicuousness of ears:

• diminution (the ear pinnae are proportionately small, https://www.dreamstime.com/royalty-free-stock-image-scimitar-oryx-sunset-image10430696).

Overall effect:
Oryx dammah fails to qualify for an auricular flag.

Adult male:
https://pngtree.com/freebackground/scimitar-horned-oryx-antelope-south-ranch-photo_7864945.html
https://www.zoochat.com/community/media/scimitar-horned-oryx-watatunga-30-7-23.675918/

Adult females:
https://www.shutterstock.com/image-photo/scimitar-oryx-dammah-known-sahara-scimitarhorned-672397882
https://es.123rf.com/photo_86609523_scimitar-oryx-%28oryx-dammah%29,-also-known-as-the-sahara-oryx-or-scimitar-horned-oryx.-.html
https://www.istockphoto.com/photo/scimitar-oryx-gm914093506-251604395?phrase=scimitar+oryx&searchscope=image%2Cfilm
https://www.dreamstime.com/scimitar-oryx-herd-close-up-image106037373 (group includes two individuals of Oryx beisa)

Juvenile female:
https://www.shutterstock.com/image-photo/scimitar-oryx-dammah-known-scimitarhorned-sahara-2388682347

ORYX LEUCORYX

Factors enhancing conspicuousness of ears:

• central darkness (pigmented bare skin, contrasting with pale pelage over rest of ear pinna).

Factors detracting from conspicuousness of ears:

• diminution (the ear pinnae are proportionately small)
• distraction by bold pattern on face.

Overall effect:
Oryx leucoryx fails to qualify for an auricular flag.

Adult females:
https://www.gettyimages.ae/detail/photo/arabian-oryx-portrait-royalty-free-image/168325322?phrase=arabian+oryx&adppopup=true
https://www.inaturalist.org/observations/26798021
https://www.ardeaprints.com/danita-delimont/dde-90025791-25408057.html
https://www.sciencephoto.com/media/589660/view/arabian-oryx-oryx-leucoryx-
https://www.shutterstock.com/image-photo/arabian-oryx-leucoryx-close-white-al-1395240884

ORYX BEISA

Factors enhancing conspicuousness of ears:

• central darkness, of size exceeding that in O. dammah and O. leucoryx
• apical darkness.

Factors detracting from conspicuousness of ears:

• distraction by facial pattern, particularly the white muzzle (https://www.istockphoto.com/photo/photo-safari-african-antelopes-gm1327296038-411694546?phrase=scimitar+oryx&searchscope=image%2Cfilm).

Overall effect:
Oryx beisa qualifies for an auricular flag.

The pale pelage of the front-of-ear seems capable of partly closing/opening, as a thermoregulatory reaction (compare https://www.istockphoto.com/photo/the-east-african-oryx-also-known-as-the-beisa-is-a-species-of-antelope-from-east-gm1438803126-479215893?phrase=east+african+oryx%2C+beisa%2C+gemsbok%2C+samburu+national+park&searchscope=image%2Cfilm with https://stock.adobe.com/images/biesa-oryx-oryx-beisa-samburu-national-reserve-kenya/130108826).

Adult males:
https://www.istockphoto.com/photo/male-oryx-gm1039746348-278346159?phrase=east+african+oryx%2C+beisa%2C+gemsbok%2C+samburu+national+park&searchscope=image%2Cfilm
https://www.naturepl.com/stock-photo-beisa-oryx-oryx-beisa-samburu-np-kenya-image01232481.html

Adult females:
https://upload.wikimedia.org/wikipedia/commons/d/dd/Common_beisa_oryx_%28Oryx_beisa_beisa%29_female.jpg
https://www.istockphoto.com/photo/male-oryx-in-samburu-kenya-gm182243202-11189074?phrase=east+african+oryx%2C+beisa%2C+gemsbok%2C+samburu+national+park&searchscope=image%2Cfilm
https://www.istockphoto.com/photo/beisa-oryx-kenya-gm152540336-11588452?phrase=east+african+oryx%2C+beisa%2C+gemsbok%2C+samburu+national+park&searchscope=image%2Cfilm
https://www.mediastorehouse.com.au/digital-wallpapers/worldinprint/beisa-oryx-east-african-oryx-oryx-beisa-3639207.html?prodid=3153
https://www.mediastorehouse.com.au/flpa/beisa-oryx-oryx-gazella-beisa-head-9665519.html
https://www.istockphoto.com/photo/the-east-african-oryx-also-known-as-the-beisa-is-a-species-of-antelope-from-east-gm1438803111-479215891?phrase=east+african+oryx%2C+beisa%2C+gemsbok%2C+samburu+national+park&searchscope=image%2Cfilm
https://www.istockphoto.com/photo/oryx-desert-antelope-gm183880545-16434887?phrase=east+african+oryx%2C+beisa%2C+gemsbok%2C+samburu+national+park&searchscope=image%2Cfilm

Adolescent:
https://www.sciencephoto.com/media/87035/view/beisa-oryx-oryx-beisa-

ORYX CALLOTIS

Factors enhancing conspicuousness of ears:

• darkness of apical tufts

Factors detracting from conspicuousness of ears:

• loss of dark/pale contrast.

Overall effect:
Oryx callotis qualifies for an auricular flag, for reasons surprisingly different from those in the case of O. beisa.

Adult males:
https://anungulateaday.tumblr.com/image/190542706179
https://stock.adobe.com/images/oryx-antilope-in-kenia/17782006?prev_url=detail
https://www.shutterstock.com/image-photo/east-african-oryx-beisa-aka-tsavo-2129271320
https://www.wintershoeksafaris.com/species/fringe-eared-oryx/
https://www.youtube.com/watch?app=desktop&v=GXYN7j1vTko

Adult females:
https://upload.wikimedia.org/wikipedia/commons/f/f6/Beisa%2C_Tsawo-Wes%2C_Tanzani%C3%AB.jpg
https://www.naturepl.com/stock-photo-fringe-eared-oryx-oryx-beisa-callotis-female-looking-back-towards-nature-image01529829.html
https://anungulateaday.tumblr.com/image/190541002784
https://anungulateaday.tumblr.com/image/190539159664
https://anungulateaday.tumblr.com/image/190537312341
https://upload.wikimedia.org/wikipedia/commons/f/f6/Beisa%2C_Tsawo-Wes%2C_Tanzani%C3%AB.jpg
https://www.flickr.com/photos/pete_steward/10703686565
https://www.flickr.com/photos/gavinkenya/21165640782/
https://www.biolib.cz/en/image/id365616/
https://www.istockphoto.com/photo/close-up-of-oryx-tsavo-national-park-kenya-gm919002354-252773496
https://www.wildlifeofkenya.com/categories/ongulates/oryx-fringe-eared/
https://www.alamy.com/roan-antelope-hippotragus-equinus-bovidae-tsavo-west-national-park-kenya-africa-image273730424.html?imageid=5CCC9A7F-3CDA-4616-BE48-B7C942CD5E23&p=39640&pn=2&searchId=fc2396d582be6b3410181e7023641baa&searchtype=0

Adolescent female:
https://upload.wikimedia.org/wikipedia/commons/f/f6/Beisa%2C_Tsawo-Wes%2C_Tanzani%C3%AB.jpg

ORYX GAZELLA

Factors enhancing conspicuousness of ears:

• enlarged size
• central and apical darkness (https://www.istockphoto.com/photo/gemsbok-oryx-gm1409920032-460301989).

Factors detracting from conspicuousness of ears:

• distraction by bold facial pattern (https://www.dreamstime.com/stock-photo-gemsbok-mother-calf-her-standing-bush-northern-cape-south-africa-image60633175 and https://matlabas.co.za/gemsbuckoryx/ and https://www.inaturalist.org/observations/185453554 and https://www.inaturalist.org/observations/144173315 and https://www.inaturalist.org/observations/58682214).

Overall effect:

• Oryx gazella qualifies for an auricular flag.

The following shows how the appearance changes when the ear pinnae happen to be folded back, subtracting their bold pattern (https://www.dreamstime.com/stock-photo-gemsbok-namibia-image10816090).

In O. gazella, unlike H. equinus, the auricular flag is clearest in adults, not juveniles. This is because the ear pinnae are not obviously precocial in either size or colouration (https://www.dreamstime.com/stock-images-young-gemsbok-oryx-antelope-kalahari-desert-image12657944 and https://www.dreamstime.com/young-gemsbok-oryx-gazella-walking-savanna-etosha-national-park-namibia-young-gemsbok-oryx-gazella-walking-image286937546 and https://www.dreamstime.com/stock-photo-young-oryx-kgalagadi-park-south-africa-image64764904 and https://www.dreamstime.com/gemsbok-mother-calf-antelope-southern-african-savanna-image143891751).

Adult male:
https://www.masterfile.com/image/en/841-05961369

Adult females:
https://www.gettyimages.co.uk/detail/photo/close-up-of-gemsbok-royalty-free-image/670987518?adppopup=true
https://www.alamy.com/gemsbok-or-gemsbuck-oryx-gazella-portrait-kgalagadi-transfrontier-image60850981.html?imageid=A35A6BE0-EDB6-4339-80CF-ACB136EBBF54&p=183828&pn=1&searchId=a5bfc98cba12eb15dd1be0367313fd95&searchtype=0
https://www.shutterstock.com/image-photo/gemsbok-portrait-etosha-desert-oryx-gazella-131298860
https://www.dreamstime.com/stock-photo-close-up-oryx-starring-camera-gemsbok-central-kalahari-botswana-image98749556

Adolescent males:
https://www.shutterstock.com/image-photo/portrait-oryx-bull-2149051503
https://www.dreamstime.com/stock-photo-close-up-gemsbok-starring-camera-oryx-kalagadi-transfrontier-park-south-africa-image94348188
https://www.dreamstime.com/young-gemsbok-oryx-grazing-kalahari-desert-south-africa-young-gemsbok-oryx-grazing-kalahari-desert-image234137001

Juvenile females:
https://www.dreamstime.com/stock-images-oryx-calf-standing-grassfield-image28879894
https://www.dreamstime.com/stock-photography-roan-antelope-image12462662
https://www.dreamstime.com/stock-photo-gemsbok-antelopes-image25673810

ADDAX NASOMACULATUS

Factors enhancing conspicuousness of ears:

• pallor, extending to posterior base of ear pinna (only in winter pelage).

Factors detracting from conspicuousness of ears:

• distraction by pallor of forequarters and most of face (summer pelage, https://stock.adobe.com/images/addax/47660518?prev_url=detail and https://stock.adobe.com/images/addax/47660512?prev_url=detail)
• distraction by bold facial pattern (winter pelage).

Overall effect:
Addax nasomaculatus may possibly qualify for anterior auricular flag in winter pelage (https://www.alamy.com/addax-addax-nasomaculatus-hai-bar-reserve-israel-image3637497.html?imageid=81028A0B-4151-454F-A2A3-080D3EED99FB&p=11788&pn=3&searchId=d449e2df5bd805fca78cd33082c5597d&searchtype=0).

However, more photographic evidence is needed.

My search-image is similar to, but better-illuminated/oriented than:
https://www.alamy.com/addax-in-captivity-addax-nasomaculatus-captive-breeding-programme-living-desert-california-western-usa-image181629044.html?imageid=47A26A1F-D1B2-48AD-9F28-52FCC8D31210&p=738284&pn=6&searchId=003977f109c1d9ffc2260bc686904ee6&searchtype=0https://www.pressenza.com/2022/01/love-for-living-animals-the-last-three-addaxes-in-the-wild-have-a-strong-potential-to-survive-climate-change-but-first-they-must-overcome-extinction/ and https://twitter.com/hallaboutafrica/status/1604719030862237696 and https://www.flickr.com/photos/42409752@N07/6265500502 and https://gvzoo.com/animals/addax and https://www.facebook.com/AnimalPlanetIndia/photos/to-cope-with-the-unforgiving-desert-sun-the-addax-sports-a-white-coat-in-the-sum/1449377625207193/?paipv=0&eav=AfbgPZi31ymGs3iK_9VuKypjqThoayy6DCUlrTJMHLYeiEUNJxvZmRgFmCWN1iL0OZg&_rdr).

Adult males in summer pelage:
https://www.gettyimages.com.au/detail/photo/addax-antelope-critically-endangered-souss-massa-royalty-free-image/128123755
Scroll to third photo in https://www.12images.net/endangered-and-extinct-animals/the-addax/

Adult male in winter pelage (figure at left):
https://www.gettyimages.com.au/detail/photo/addax-addax-nasomaculatus-bahrain-royalty-free-image/90064780?phrase=addax+antelope&adppopup=true

Adult males in intermediate pelage:
https://www.alamy.com/addax-antelope-addax-nasomaculatus-arid-zones-of-north-africa-but-image1834043.html?imageid=5F2B3FCF-A2E8-4E47-82CA-B491884E3D98&p=3864&pn=2&searchId=ed4ba9edbd01608b1adfdda836f362bb&searchtype=0
https://www.alamy.com/addax-in-desert-addax-nasomaculatus-reintroduced-to-morocco-critically-endangered-souss-massa-national-park-morocco-image181658135.html?imageid=E0FF89E9-4443-47C7-BA49-B42AF5DF6AB5&p=738474&pn=6&searchId=003977f109c1d9ffc2260bc686904ee6&searchtype=0

Adult females in summer pelage:
https://www.gettyimages.com.au/detail/photo/addax-considers-a-stone-royalty-free-image/186138870?phrase=addax+antelope&adppopup=true
https://stock.adobe.com/images/addax-addax-nasomaculatus-also-known-as-the-white-antelope-and-the-screwhorn-antelope-is-an-antelope-of-the-genus-addax-that-lives-in-the-sahara-desert/293706030?prev_url=detail
https://www.bigstockphoto.com/image-42519667/stock-photo-addax

Juvenile male:
https://stlzoo.org/conservation/reproductive-sciences

to be continued in https://www.inaturalist.org/journal/milewski/88221-adaptive-radiation-of-auricular-flags-in-hippotragin-bovids-hippotragus-oryx-and-addax-part-2#...

Posted on December 29, 2023 08:56 PM by milewski