The following illustrate juveniles of the eastern white-bearded wildebeest (Connochaetes albojubatus, https://www.inaturalist.org/observations?taxon_id=525438) at an ontogenetic stage corresponding in body mass approximately to adults of the coexisting Maasai ostrich (Struthio camelus massaicus, https://www.inaturalist.org/observations?taxon_id=322201).
Please note that the body mass has just exceeded half of maternal body mass, but the horns - albeit much longer than the ears or mane - are still simple spikes directed dorsally.
https://www.inaturalist.org/observations/7898982
https://www.inaturalist.org/observations/110103601
https://www.inaturalist.org/observations/124808683
https://www.inaturalist.org/observations/102212589
https://www.inaturalist.org/observations/189131122
https://www.inaturalist.org/observations/191952637
Scroll in https://fossilrim.org/animals/common-wildebeest/
Scroll in https://www.zootierliste.de/en/?klasse=1&ordnung=121&familie=12115&art=1160826
Compare with
Sample size large, of both sexes
Location:
Wildlife Ranching and Research, later Swara Plains Conservancy, and now incorporated into Nairobi National Park
Time:
1986-1989
The following are mean values of percentage of body mass, followed by the actual masses in parentheses.
Body mass 111 kg
Carcass mass = 54.22% (60.184 kg)
Skin = 7.92% (8.788 kg)
Feet = 2.93% (3.253 kg)
Head = 7.29% (8.088 kg)
Brain = 0.267% (0.296 kg)
Eyeballs = 0.0438% (2 X 0.0243 kg)
Tongue = 0.23% (0.259 kg)
Masseter muscle = 0.266% (2 X 0.148 kg)
Heart = 0.726% (0.806 kg)
Lungs = 1.55% (1.726 kg)
Spleen = 0.35% (0.392 kg)
Liver = 1.28% (1.422 kg)
Kidneys = 0.265% (2 X 0.147 kg)
Rumen = 1.67% (1.859 kg)
Reticulum = 0.275% (0.305 kg)
Omasum = 0.43% (0.480 kg)
Abomasum = 0.34% (0.375 kg)
Total intestines (full?) = 4.83% (5.363 kg)
Total stomach = 2.72% (3.019 kg)
DISCUSSION
Elsewhere in this series of Posts, I compare the Maasai ostrich with a coexisting alcelaphin ruminant - namely Alcelaphus cokii (https://www.inaturalist.org/observations?taxon_id=132649) - of similar adult body mass to the bird.
The values presented here - except for brain and skin - exceed those of adults of A. cokii, of similar body mass, in their overall resemblance to the Maasai ostrich.
The ostrich is constituted in some ways like juveniles of a ruminant, with big organs and feet (suggesting emphasis on mobility and foraging and rapid metabolism).
Comentarios
https://www.zoonewengland.org/franklin-park-zoo/our-animals/mammals/hoofed/white-bearded-wildebeest/
https://www.projectnoah.org/spottings/18461167
Shift
https://www.dreamstime.com/wildebeest-up-close-grass-background-side-image201400889
Shift to gaits
https://stock.adobe.com/images/white-bearded-wildebeest-walking-through-water-in-amboseli-national-park-in-kenya/385489757?prev_url=detail
https://stock.adobe.com/images/white-bearded-wildebeest-on-the-migration-tanzania/57554246?prev_url=detail
https://www.inaturalist.org/observations/132555239
https://www.inaturalist.org/observations/107424110
https://www.inaturalist.org/observations/104440930
Shift
https://stock.adobe.com/images/a-black-backed-jackal-and-a-wildebeest-kill-kenya-africa/487017090?prev_url=detail
https://dakotareflections.com/endangered%20species/fossil%20rim%20wildlife%20center.html
https://www.inaturalist.org/observations/183000464
https://www.inaturalist.org/observations/151219663
https://www.inaturalist.org/observations/131117864
https://www.inaturalist.org/observations/131179804
https://www.inaturalist.org/observations/110949669
https://www.inaturalist.org/observations/106979241
https://www.inaturalist.org/observations/106811995
https://www.inaturalist.org/observations/101346821
https://www.inaturalist.org/observations/70439679
https://www.inaturalist.org/observations/19324352
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