Adaptive colouration in the hard-ground barasingha (Rucervus duvaucelii branderi)

Also see https://www.inaturalist.org/posts/90985-a-collation-of-sundry-some-mislabelled-photos-of-the-puku-kobus-vardoni-on-the-web-part-1#

The hard-ground barasingha (Rucervus duvaucelii branderi) has remarkably plain colouration for a large, gregarious ruminant (https://www.inaturalist.org/observations/41060671 and https://www.inaturalist.org/observations/135787270 and https://www.inaturalist.org/observations/123326209 and https://www.gettyimages.com.au/detail/photo/hard-ground-swamp-deer-barasingha-royalty-free-image/178208647?phrase=swamp+deer&adppopup=true and https://www.gettyimages.com.au/detail/photo/barasingha-stags-royalty-free-image/495063657?phrase=swamp+deer&adppopup=true and https://www.alamy.com/stock-photo-barasingha-12-tined-deer-also-known-as-swamp-deer-71617444.html?imageid=7FF4EC5B-7908-48DE-AAD0-B26E6C3A92D2&p=215720&pn=1&searchId=276985531ee281cf572c89f88e85bd3d&searchtype=0 and https://www.flickr.com/photos/reflections-nmp/5685437727 and https://www.flickr.com/photos/cirdan-travels/25759806461).

However, it shows the following:

  • sexual dimorphism, in which mature males are darker than adult females and lack countershading on the torso,
  • a possible caudal flag,
  • anterior and posterior auricular flags, and
  • a buccal semet.

In interpreting the photos of the hard-ground barasingha on the Web, please remember that Kanha National Park is closed to visitors during the rainy season in summer, which lasts 4.5 months (https://www.kanha-national-park.com/best_time_to_visit.html#:~:text=Kanha%20National%20Park%20in%20Madhya,weather%20becomes%20pleasant%20this%20time and https://www.thewildlifeindia.com/2022/09/Monsoon-Magic-of-Kanha-National-Park-Meadows.html).

Although the antlers are shed in the dry season, I have yet to see a photo of any mature male in the antlerless condition or in young velvet.

SEXUAL DIMORPHISM

The following shows that, during the rutting season, mature males have shaggy pelage while adult females retain summer pelage (https://www.alamy.com/stock-photo-barasingha-deer-or-swamp-deer-cervus-duvauceli-male-and-female-india-111494883.html?imageid=CBF16B70-FEA4-4F8C-8CE3-B0ADAD81EC0A&p=329545&pn=1&searchId=276985531ee281cf572c89f88e85bd3d&searchtype=0).

The following show that adult males lack countershading on the torso, enhancing their conspicuousness (https://www.flickr.com/photos/hmadan/4205687133 and https://www.inaturalist.org/observations/123287742 and https://www.inaturalist.org/observations/72271929 and https://www.inaturalist.org/observations/41095389 and https://www.alamy.com/buck-barasingha-recurvus-duvaucelii-in-kanha-national-park-india-image361790523.html?imageid=368FF456-4A1B-42FA-9DE7-8CC82FF8FA27&p=143932&pn=2&searchId=9457f45e1535e0baeab1d072e9f2dbd7&searchtype=0 and https://www.alamy.com/barasingha-swamp-deer-in-india-image217155284.html?imageid=9C92EA35-0044-4A0D-AC43-A22A4B7C18C3&p=149431&pn=1&searchId=276985531ee281cf572c89f88e85bd3d&searchtype=0).

The following shows that adult but not fully mature males have not necessarily developed this feature yet (https://www.inaturalist.org/observations/123284736).

Adult males possess a poorly-developed and individually variable muzzle-ring (https://www.inaturalist.org/posts/55779-the-muzzle-ring-as-a-deep-ancestral-marker-in-deer-part-1).

This is shown in https://www.alamy.com/stock-photo-barasingha-12-tined-deer-72093014.html and https://www.alamy.com/stock-photo-swamp-deer-barasingha-kanha-national-park-103926875.html?imageid=736E7E6C-7E36-4689-B53E-9A618B953BD0&p=300848&pn=1&searchId=276985531ee281cf572c89f88e85bd3d&searchtype=0 and https://www.alamy.com/close-up-of-a-swamp-deer-rucervus-duvaucelii-kanha-national-park-madhya-pradesh-india-image376770510.html and https://www.shutterstock.com/image-photo/male-barasingha-swamp-deer-rucervus-duvaucelii-686501974 and https://www.alamy.com/hard-ground-swamp-deer-or-barasingha-cervus-duvauceliithreatened-kanha-image6941233.html and https://www.agefotostock.com/age/en/details-photo/barasingha-central-hardground-or-swamp-deer-cervus-duvaucelii-branderi-in-kanha-national-park-madhya-pradesh-india/X1B-904819 and https://www.agefotostock.com/age/en/details-photo/barasingha-swamp-deer-rucervus-duvaucelii-male-grazing-kanha-national-park-madhya-pradesh-india-asia/AAM-AAES111859 and https://nickgarbutt.photoshelter.com/image/I0000nl2DBDcw4UE and https://www.alamy.com/stock-photo-a-hard-ground-barahsinga-rucervus-duvauceli-branderi-grazing-at-kanha-35435038.html?imageid=37304E47-F115-47B3-9321-47F798B2EA43&p=12384&pn=2&searchId=9457f45e1535e0baeab1d072e9f2dbd7&searchtype=0 and https://www.ardeaprints.com/jr-745-1304405.html and https://www.gettyimages.com.au/detail/photo/barasingha-deer-and-mynas-royalty-free-image/521358970?phrase=swamp+deer&adppopup=true and https://www.facebook.com/amanwilsonphotography/photos/hard-ground-swamp-deer/1225524230870187/).

The following (https://www.inaturalist.org/observations/48644048 and https://www.alamy.com/stock-photo-barasingha-deer-or-swamp-deer-cervus-duvauceli-male-111494839.html?imageid=9D42A777-F780-49CC-A47C-1DAB3977E1A2&p=329545&pn=1&searchId=276985531ee281cf572c89f88e85bd3d&searchtype=0) show that adult males may possess pale

  • at the crook-of-throat, and
  • at the tips of the tines of the antlers (at least in some individuals).

The following shows that the spotting on the body fades early in juveniles, but is retained along the dorsal line in adult females in summer pelage (https://www.alamy.com/stock-photo-stah-does-barasingha-aka-swamp-deer-cervus-duvauceli-kanha-tiger-reserve-24557302.html?imageid=36B59956-4568-48E0-9348-D7CA71FC7D73&p=135160&pn=1&searchId=276985531ee281cf572c89f88e85bd3d&searchtype=0).

In 'winter' pelage, the dark dorsal stripe is somewhat retained, but the accompanying pale spots become faint (https://www.naturepl.com/stock-photo/hard-ground-barasingha--upland-barasingha--swamp-deer-%28cervus-duvauceli/search/detail-0_01345300.html).

POSSIBLE CAUDAL FLAG

The following show that there is a considerable pattern on the hindquarters (https://www.gettyimages.com.au/detail/news-photo/barasingha-or-swamp-deer-cervidae-news-photo/492765651?adppopup=true and https://www.inaturalist.org/observations/157012022 and https://www.alamy.com/india-barasingha-southern-swamp-deer-rucervus-duvaucelii-branderi-at-kanha-tiger-reserve-image226010798.html?imageid=6CAC9BD2-38D4-4478-B311-33562A557B7E&p=158464&pn=2&searchId=9457f45e1535e0baeab1d072e9f2dbd7&searchtype=0 and https://www.inaturalist.org/observations/56530542).

The ventral surface of the tail is white (https://www.kanha.co.in/kanha-wildlife/kanha-barasingha.html).

However, the tail is small. Furthermore, in most views, the pattern on and near the tail is so subtle as to be hardly noticeable (https://www.alamy.com/stock-photo-stah-does-barasingha-aka-swamp-deer-cervus-duvauceli-kanha-tiger-reserve-26521418.html?imageid=8362A2B4-A2CF-4065-97AF-533B49F54364&p=135160&pn=3&searchId=7cd4c73a247af679b402df2f61bcb554&searchtype=0 and https://www.gettyimages.com.au/detail/photo/swamp-deer-or-barasingha-royalty-free-image/981724418?phrase=swamp+deer&adppopup=true and https://www.alamy.com/swamp-deer-also-known-as-baraginga-rucervus-duvaucelii-male-from-kanha-national-park-madhya-pradesh-india-image473715869.html?imageid=D03B6D4F-3C7D-44B1-AD4A-8805A87AFEF9&p=1910266&pn=3&searchId=7cd4c73a247af679b402df2f61bcb554&searchtype=0 and https://www.superstock.com/asset/hard-ground-swamp-deer-pond-cervus-duvauceli-branderi-kanha-national/4220-20145884).

The following shows that adult males do not display the tail when fleeing (https://www.flickr.com/photos/girlslens/42013764681 and https://www.agefotostock.com/age/en/details-photo/hard-ground-swamp-deer-leaping-cervus-duvauceli-branderi/MEV-10788396).

The possibility remains that the hard-ground barasingha possesses a caudal flag in a social/sexual context. However, the photographic evidence has yet to emerge.

AURICULAR FLAGS

The following show that the anterior surface of the ear pinna, which is extremely hairy in the hard-ground barasingha, is conspicuously pale (https://www.alamy.com/stock-photo-female-barasingha-aka-swamp-deer-cervus-duvauceli-kanha-tiger-reserve-24557283.html?imageid=A9389520-61FB-49BC-A345-D584F311F213&p=135160&pn=3&searchId=7cd4c73a247af679b402df2f61bcb554&searchtype=0 and https://www.gettyimages.com.au/detail/photo/barasingha-royalty-free-image/495374407?phrase=swamp+deer&adppopup=true).

The following shows that this persists somewhat in mature males, despite the overall darkening of the pelage (https://nickgarbutt.photoshelter.com/image/I0000IfnSIMigzrw and https://www.gettyimages.com.au/detail/news-photo/barasingha-or-swamp-deer-cervidae-news-photo/492765653?adppopup=true and https://www.gettyimages.com.au/detail/photo/swamp-deer-or-barasingha-stags-royalty-free-image/114571486?phrase=swamp+deer&adppopup=true).

The following show that the posterior of the ear is pale at its base and on the ventral surface of the pinna (https://www.shutterstock.com/image-photo/two-female-barasingha-swamp-deer-rucervus-2303161159 and https://www.alamy.com/two-female-barasingha-or-swamp-deer-rucervus-duvaucelii-kanha-national-park-india-image551808559.html?imageid=D270AC8A-B237-4F0F-86EC-F573C241279D&p=70019&pn=1&searchId=276985531ee281cf572c89f88e85bd3d&searchtype=0).

The following hints that this feature may be reduced or absent in mature males (https://3.bp.blogspot.com/-T-LSDuDf67E/S5I5vDt4v_I/AAAAAAAAAsM/Lac7IzM2CBAbXjnWpxfje4VpDuo_Vl6fACPcBGAYYCw/s1600/Barasingha%2Bin%2BFlight.jpg).

However, as for the loss of countershading on the torso, this may apply only to fully mature males (https://www.istockphoto.com/photo/barasingha-or-swamp-deer-crossing-the-road-at-kanha-national-park-madhya-pradesh-gm1143848337-307332227 and https://www.shutterstock.com/image-photo/barasinga-popularly-known-swamp-deer-found-1212245020 and https://www.alamy.com/stock-photo-swamp-deer-cervus-duvauceli-india-34384520.html?imageid=1D376CF4-2092-47DC-B616-E11D3E488747&p=5264&pn=2&searchId=9457f45e1535e0baeab1d072e9f2dbd7&searchtype=0 and https://www.alamy.com/stock-photo-barasingha-deer-or-swamp-deer-cervus-duvauceli-males-india-111494877.html?imageid=D4AEB073-F7C3-44EE-B4F2-5843F7EE009B&p=329545&pn=2&searchId=9457f45e1535e0baeab1d072e9f2dbd7&searchtype=0 and https://www.alamy.com/swamp-deer-also-known-as-barasinga-rucervus-duvaucelii-feeding-in-kanha-national-park-madhya-pradesh-india-image473710698.html?imageid=4C52A322-53E0-46DD-A04F-D8D9588A99F5&p=1910266&pn=3&searchId=7cd4c73a247af679b402df2f61bcb554&searchtype=0).

BUCCAL SEMET

The following show the sexual difference in the pattern of dark and pale at the mouth (https://www.alamy.com/stock-photo-barashingha-deer-or-swamp-deer-cervus-duvauceli-males-fighting-111494576.html?imageid=AFAFB591-BE9D-4EA0-A8D8-33F1D79C4C68&p=329545&pn=2&searchId=9457f45e1535e0baeab1d072e9f2dbd7&searchtype=0 and https://www.shutterstock.com/image-photo/female-barasingha-swamp-deer-rucervus-duvaucelii-1476784394).

The buccal semet in females conforms to what I have previously called a gape-spot (https://www.inaturalist.org/journal/milewski/55804-the-muzzle-ring-as-a-deep-ancestral-marker-in-deer-part-2-the-gape-spot).

DISCUSSION

From one perspective, the hard-ground barasingha is simply a dull version of various patterns of colouration widespread in cervids, particularly on the tail and buttocks, and on the muzzle.

However, this hardly does justice to the topic.

From another perspective, what is most remarkable about this colouration is the anterior auricular flag, which is better-developed than in most cervids.

However, this, too, needs qualification. The main reason for the conspicuousness of the white hairs on the front-of-ear may be the sheer hairiness of this surface - possibly explained by protection from blood-sucking insects in marshes.

From a different perspective again, what is most noteworthy about the adaptive colouration of the hard-ground barasingha is the seasonal change in the length of the pelage, which is also involved in sexual dimorphism.

What is odd about this seasonal change is that the habitat of this subspecies lies in the tropics, where the climate in 'winter' is mild. Comparable bovids under similar climates in Africa, such as Kobus (https://www.inaturalist.org/observations?place_id=any&taxon_id=42325&view=species), show no seasonal changes in pelage.

At the same time, this makes little difference to the adaptive colouration, because the relatively bright hue of the summer pelage (https://www.inaturalist.org/observations/157012025 and https://3.bp.blogspot.com/-nXWgDhRaP-8/SBq1CvQ0A1I/AAAAAAAAAOE/nflIUIX3-UA/s1600/Swampdeer.jpgv and https://4.bp.blogspot.com/-GAns8sSDDwQ/SBq1HfQ0A2I/AAAAAAAAAOM/G28tNH_0lZA/s1600/swamp-deer.jpg) is not necessarily visible to ungulates and carnivores.

Overall, my finding is that the most important pattern in the colouration of the hard-ground barasingha is the auricular flags in females (https://www.natureinstock.com/search/preview/hard-ground-barasingha-upland-barasingha-swamp-deer-cervus-duvauceli/0_12200926.html and https://www.shutterstock.com/editorial/image-editorial/nature-4907890a).

The colouration on the front-of-ear differs slightly from that of comparable reduncin bovids. However, the ears are considerably more noticeable in the hard-ground barasingha than in e.g. Kobus vardoni (https://www.edwardselfephotosafaris.com/know-your-african-wildlife-puku).

ADDITIONAL ILLUSTRATIONS

https://www.dreamstime.com/barasingha-rucervus-duvaucelii-swamp-deer-herd-family-elusive-vulnerable-animal-walking-near-water-body-image214404584

https://www.shutterstock.com/image-photo/female-barasingha-swamp-deer-rucervus-duvaucelii-1011360667

https://www.shutterstock.com/image-photo/barasingha-rucervus-duvaucelii-swamp-deer-females-2228931865

https://www.shutterstock.com/image-photo/male-barasingha-swamp-deer-rucervus-duvaucelii-386253931

https://www.facebook.com/NatureSafari/photos/a.223692954396654/3218918674874052/?type=3

https://www.agefotostock.com/age/en/details-photo/swamp-deer-rucervus-duvaucelii-branderi-hard-ground-form-adult-male-with-black-drongo-dicrurus-macrocercus-adult-perched-on-back-kanha-n-p/FHR-10310-00078-852

https://www.biome-project.co.uk/post/barasingha-the-elusive-swamp-deer-of-india

https://www.facebook.com/thecorbettfoundation/photos/the-hard-ground-barasingha-a-subspecies-of-the-swamp-deer-is-listed-as-vulnerabl/10152567807566906/

https://www.alamy.com/barasingha-swamp-deer-standing-in-water-india-image354872859.html?imageid=7EBEDFD8-5D10-4E8D-BA0E-4C289A9AFC37&p=1132882&pn=1&searchId=276985531ee281cf572c89f88e85bd3d&searchtype=0

https://www.alamy.com/stock-photo-female-swamp-deer-or-barasingha-suckling-a-fawn-44039365.html?imageid=CC3B8CE1-6033-4757-8478-5FBE11271618&p=15397&pn=1&searchId=276985531ee281cf572c89f88e85bd3d&searchtype=0

https://www.alamy.com/stock-photo-barasingha-deer-or-swamp-deer-cervus-duvauceli-males-fighting-111494993.html?imageid=5E2288AC-B92F-42A1-8EBC-6D43DB31D48E&p=329545&pn=3&searchId=7cd4c73a247af679b402df2f61bcb554&searchtype=0

Posted on May 27, 2023 08:28 PM by milewski milewski

Comments

Posted by milewski almost 1 year ago

I suspect that the following is mislabelled, and that the location is not Kanha National Park:

https://www.flickr.com/photos/cjb22222222/49083263751

Posted by milewski almost 1 year ago

Add a Comment

Sign In or Sign Up to add comments