Please see https://focusedcollection.com/164919712/stock-photo-hartebeest-and-topi-standing.html.
The topi (Damaliscus korrigum jimela, https://www.inaturalist.org/observations?taxon_id=132769) is known for standing on termite mounds - even more than in the case of Alcelaphus cokii (https://www.inaturalist.org/journal/milewski/71425-does-coke-s-hartebeest-alcelaphus-cokii-show-sentry-behaviour#).
Both males and females participate in this behaviour. And, even more than in A. cokii, the sexes are similar in body size and in the size and shape of the horns.
Estes (1991) states: "Topis and termite mounds go together...Every desirable territory has elevations, some of which are regularly used as vantage points. But females and young use them too, so not every topi sentinel is a male advertising territorial status - it may be a female in the alert posture...Nor are preorbital-gland marking, ground-horning, and mud-packing confined to territorial males. Both sexes perform these acts in the same way...Harem males display a proprietary interest in females and young that is otherwise unusual in territorial males. While remaining vigilant against trespassers, a preoccupation that often keeps them on patrol or on sentry duty atop a mound, they play a watchdog role, warning the herd of danger (alarm snorts), leading or directing the retreat, and stationing themselves between the herd and predators."
It is clear from this quote that Estes, an authority on behaviour in alcelaphins, accepted that both sentry behaviour and altruism occur in the topi. There is also an implication that the roles of males and females overlap in these respects.
Given the exceptional sexual monomorphism in the topi, I have taken the opportunity to record the sex-ratio of individuals photographed standing vigilant on termite mounds in the Serengeti ecosystem.
The number of photos showing the topi on termite mounds, on the Web, is too great for any attempt at a complete compendium. So, my sampling method has been to take the first 100 photos (beginning with those in iNaturalist), and to treat them as a representative sample.
I have omitted photos in the following categories:
The following are the results of my sampling. In about 35% of the photos, it is females that are featured - indicating a sex ratio of about two males to one female in what I take to be, at least partly, a role of sentry for the group.
ADULT MALES
https://www.shutterstock.com/image-photo/topi-stand-on-termite-mound-40854139
https://www.inaturalist.org/observations/123243465
https://www.inaturalist.org/observations/123164511
https://www.inaturalist.org/observations/115911956
https://www.inaturalist.org/observations/135946470
https://www.inaturalist.org/observations/104970168
https://www.inaturalist.org/observations/103654841
https://www.inaturalist.org/observations/102815967
https://www.inaturalist.org/observations/81238643
https://www.inaturalist.org/observations/80550692
https://www.inaturalist.org/observations/63320104
https://www.inaturalist.org/observations/61542664
https://www.inaturalist.org/observations/55245932
https://www.inaturalist.org/observations/57370826
https://www.inaturalist.org/observations/55110834
https://www.inaturalist.org/observations/46188741
https://www.inaturalist.org/observations/39277737
https://www.inaturalist.org/observations/36988381
https://www.inaturalist.org/observations/36446483
https://www.inaturalist.org/observations/21242045
https://www.inaturalist.org/observations/22703876
https://www.inaturalist.org/observations/10801033
https://www.inaturalist.org/observations/9883471
https://www.inaturalist.org/observations/8064157
https://www.inaturalist.org/observations/6810865
https://www.inaturalist.org/observations/6484967
https://www.alamy.com/stock-photo-topi-damaliscus-korrigum-standing-on-a-termite-mound-79611584.html
https://www.alamy.com/long-shot-of-a-topi-on-a-termite-mound-in-masai-mara-image363612393.html
https://www.alamy.com/stock-photo-topi-damaliscus-korrigum-adult-on-termite-hill-kenya-111494921.html
https://www.alamy.com/male-topi-stands-on-sunlit-termite-mound-image364674128.html
https://www.alamy.com/stock-photo-topi-damaliscus-korrigum-standing-on-a-termite-mound-79611585.html
https://www.alamy.com/side-profile-of-a-topi-standing-on-a-mound-in-the-masai-mara-kenya-these-animals-find-a-high-vantage-point-to-watch-for-predators-that-may-be-hidden-image260305200.html
https://www.alamy.com/side-profile-of-a-topi-damaliscus-lunatus-jimela-standing-on-a-mound-in-the-masai-mara-kenya-these-animals-find-a-high-vantage-point-to-watch-for-image452459982.html
https://www.alamy.com/front-on-view-of-topi-on-a-termite-mound-in-masai-mara-image363612396.html
https://www.alamy.com/side-profile-of-a-topi-damaliscus-lunatus-jimela-standing-on-a-mound-in-the-masai-mara-kenya-these-animals-find-a-high-vantage-point-to-watch-for-image368249599.html
https://www.alamy.com/a-male-topi-standing-guard-on-mound-image4450576.html
JUVENILE MALES
https://www.inaturalist.org/observations/106517990
FEMALES
https://www.dreamstime.com/topi-stands-termite-mound-profile-image180085181
https://www.inaturalist.org/observations/123269506
https://www.inaturalist.org/observations/104698649
https://www.inaturalist.org/observations/68523714
https://www.inaturalist.org/observations/47377568
https://www.inaturalist.org/observations/36514600
https://www.inaturalist.org/observations/30840859
https://www.inaturalist.org/observations/27272205
https://www.inaturalist.org/observations/20817321
https://www.alamy.com/topi-standing-on-a-termite-mound-image332508368.html
https://www.dreamstime.com/male-topi-termite-mound-turns-head-image176022938
https://www.alamy.com/topi-stands-on-termite-mound-in-profile-image354491788.html
https://www.alamy.com/male-topi-stands-on-sunny-termite-mound-image349041446.html
https://www.alamy.com/the-topi-damaliscus-lunatus-standing-upright-on-a-termite-mound-on-image5221749.html
https://www.pixtastock.com/photo/63407553
https://images.russellbevanphotography.com/image/I0000.esnt81VRfI
https://www.gettyimages.com.au/detail/photo/topi-on-termite-mound-royalty-free-image/867616398
https://stock.adobe.com/images/topi-antelope-standing-on-a-termite-mound-in-the-masai-mara/284321662
https://www.alamy.com/topi-on-termite-mound-maasai-mara-kenya-image459284926.html
https://www.stevebloom.com/index.php?page=single&id=511097-BS1
INFANTS
https://www.inaturalist.org/observations/18069349
DISCUSSION
The topi is remarkable for its flexibility of social and sexual behaviour. This is well-described by Estes (1991), on pages 142-146.
The following quote from Estes, referring more broadly to the whole jimela-korrigum-lunatus complex in genus Damaliscus, may be informative.
"Topi social and reproductive organisation appears to be more variable than that of any other antelope...between perennially sedentary-dispersed and perennially mobile-aggregated...from large territories with resident female herds to small temporary territories in aggregations, to breeding leks in arenas...depending on habitat and social organisation, calves may be either hiders or followers...Serengeti females have been known to frequent a single territory for 3 years...The resident male has a more or less exclusive harem...the females play an active part, as does the male, in preventing outside topis of either sex from settling on their property...In the bull's absence, the dominant cow may actually behave like a territorial male...The sexes look so alike that this mimicry is apparently as convincing to other topis as it is to the human observer...The topi's maternal bond lasts only a year...Topis mature about a year sooner than hartebeests."
For an index to my many Posts about the genus Damaliscus, please see https://www.inaturalist.org/journal/milewski/78238-an-index-to-my-posts-on-genus-damaliscus#.
Comments
Shift
https://www.istockphoto.com/photo/an-eland-antelope-in-natural-habitat-south-africa-gm1393071121-449103768?utm_source=unsplash&utm_medium=affiliate&utm_campaign=srp_photos_top&utm_content=https%3A%2F%2Funsplash.com%2Fs%2Fphotos%2Feland&utm_term=eland%3A%3A%3A
Shift
https://www.isafiri.com/wild-life-and-birds/hartebeest
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