Adaptive colouration in wildebeests, part 5: infants and juveniles

In all forms of wildebeest, infants differ in colouration from adults. However, only in albojubatus and mearnsi do infants have clearly conspicuous colouration, particularly a facial flag (mearnsi https://www.inaturalist.org/observations/56613390). Juveniles tend to have pale lower legs (e.g. mearnsi https://www.dreamstime.com/black-bearded-wildebeest-calf-sun-serengeti-national-park-tanzania-black-bearded-wildebeest-calf-image138715372; taurinus eastern form https://www.inaturalist.org/observations/69999952 and https://www.inaturalist.org/observations/68446870 and https://www.shutterstock.com/nb/image-photo/mother-baby-wildebeest-looking-into-camera-570210484; and ?western form https://www.inaturalist.org/observations/64877990), possibly qualifying as a pedal flag.

In gnou, infants have cryptic colouration with a tendency for a dark face and pale feet.
https://www.dreamstime.com/black-wildebeest-connochaetes-gnou-female-young-image196305454
https://www.shutterstock.com/nb/image-photo/baby-wildebeest-gnu-standing-field-flowers-157837694
https://www.shutterstock.com/nb/image-photo/very-young-black-wildebeest-calf-has-1671747409
https://www.newquayzoo.org.uk/explore/news/detail/zoo-celebrates-black-wildebeest-breeding-success
https://www.newquayzoo.org.uk/explore/news/detail/zoo-celebrates-black-wildebeest-breeding-success
https://www.zooborns.com/.a/6a010535647bf3970b011571a1f52b970b-pi
https://www.zooborns.com/.a/6a010535647bf3970b011570accbf3970c-pi
https://www.zooborns.com/.a/6a010535647bf3970b011571a1f4c4970b-pi
http://www.biodiversityexplorer.info/mammals/ruminantia/connochaetes_gnou.htm
https://www.inaturalist.org/observations/11205548
https://www.dreamstime.com/royalty-free-stock-photos-teaching-them-young-black-wildebeest-mynah-jockey-image32075928

In mearnsi, infants possess a facial flag in which the dark of the muzzle contrasts with the pale of the cheeks.
https://www.alamy.com/brindled-gnuwildebeest-connochaetes-taurinus-female-with-calf-tanzania-image277611301.html
https://www.shutterstock.com/nb/image-photo/adult-wildebeest-stands-beside-recently-born-1277282221
https://www.shutterstock.com/nb/image-photo/great-migration-wildebeests-serengeti-national-park-25884934

In albojubatus, infants possess a facial flag and pale feet. In contrast to mearnsi, the facial flag is not lost in the juvenile, being part of adult colouration.
https://www.flickr.com/photos/sdzooglobal/36459319626
https://www.shutterstock.com/nb/image-photo/wildebeest-baby-340723058
https://www.dreamstime.com/stock-photo-wildebeest-calf-connochaetes-taurinus-image19692550
https://www.shutterstock.com/nb/image-photo/wildebeest-wildebai-called-gnu-antelope-genus-1342107800
https://www.shutterstock.com/nb/image-photo/wildebeest-wildebai-called-gnu-antelope-genus-1342107806
https://www.shutterstock.com/nb/image-photo/baby-wildebeest-467971799

Several forms of wildebeest have individually variable pale chevrons on the forehead of juveniles, but only in albojubatus does this contrast enough with the adjacent dark to qualify as part of a facial flag. What this means is that the facial flag, which distinguishes albojubatus from all other forms of wildebeest in adulthood, is also particularly well-developed in infants and juveniles.
https://www.shutterstock.com/nb/image-photo/africa-taken-serengeti-national-park-ngorongoro-1156350799

In taurinus eastern form, infants have cryptic colouration with an individually variable tendency for a dark face: https://www.shutterstock.com/nb/image-photo/baby-wildebeest-on-savannah-1922875088 and https://www.shutterstock.com/nb/image-photo/wildebeest-young-mother-50308903 and https://www.shutterstock.com/nb/image-photo/baby-wildebeest-91339199
https://www.flickr.com/photos/42021677@N08/24892632652/ and https://www.alamy.com/baby-wildebeest-kruger-national-park-image231960401.html and https://www.alamy.com/stock-photo-baby-wildebeest-look-on-curiously-21861364.html and https://www.shutterstock.com/nb/image-photo/kruger-national-park-portrait-wildebeest-calf-1927303538

In taurinus western form, infants are similar to those of the eastern form:
https://www.dreamstime.com/young-blue-wildebeest-calf-connochaetes-taurinus-kalahari-desert-south-africa-blue-wildebeest-calf-kalahari-desert-image112359328 and https://www.dreamstime.com/stock-photo-blue-wildebeest-calf-young-connochaetes-taurinus-kalahari-south-africa-image72782178 and https://www.shutterstock.com/nb/image-photo/blue-wildebeest-calf-standing-kgalagadi-transfrontier-1975729217 and https://www.dreamstime.com/young-calf-blue-wildebeest-looking-curiously-camera-gnus-connochaetes-taurinus-common-white-bearded-also-called-image179429613 and https://www.dreamstime.com/stock-photo-adult-calf-blue-wildebeest-connochaetes-taurinus-catt-cattle-egrets-standing-grass-okavango-delta-botswana-image67079498.

Posted by milewski milewski, 10 July, 2021 04:52

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The following shows about the maximum dark/pale contrast on the forehead of juvenile mearnsi: https://www.dreamstime.com/blue-wildebeest-calf-stands-turning-to-camera-image154106446

Posted by milewski over 1 year ago (Flag)
Posted by milewski over 1 year ago (Flag)

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