Sex-ratio of standing on termite mounds by the topi (Damaliscus korrigum jimela)

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 figure is too distant for the sex to be identified, and
• two or more adult individuals are depicted standing on top of the same mound.

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.alamy.com/topi-standing-on-a-termite-hill-image-taken-in-the-maasai-mara-kenya-image360636723.html

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://es.123rf.com/photo_94124022_antelope-topi-is-standing-on-the-termite-mound-in-serengeti-national-park-tanzania-africa.html

https://www.mediastorehouse.com.au/danita-delimont/topi-standing-guard-termite-mound-masai-mara-13913095.html#openModal

https://www.superstock.com/asset/topi-antelope-standing-termite-mound-one-classic-sights-maasai-mara/4141-49401

https://www.alamy.com/topi-damaliscus-lunatus-standing-on-termite-mound-masai-mara-national-reserve-kenya-africa-image236056271.html

https://www.alamy.com/stock-photo-topi-damaliscus-korrigum-standing-on-a-termite-mound-79611584.html

https://www.alamy.com/stock-photo-topi-damaliscus-lunatus-jimela-male-standing-on-a-termite-mound-masai-138190804.html

https://www.alamy.com/topi-damaliscus-lunatus-standing-on-a-termite-mound-damaliscus-lunatus-maasai-mara-national-reserve-kenya-image263195580.html

https://www.alamy.com/stock-photo-kenya-masai-mara-masai-mara-game-reserve-a-topi-damaliscus-korrigum-19323751.html

https://www.alamy.com/stock-photo-topi-standing-guard-on-termite-mound-maasai-mara-kenya-54685707.html

https://www.alamy.com/stock-photo-topi-standing-on-a-termite-mound-to-claim-territory-in-kenya-the-animal-34770002.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/stock-photo-tsessebe-or-sassaby-damaliscus-lunatus-jimela-standing-in-a-typical-59213721.html

https://www.alamy.com/stock-photo-topi-damaliscus-lunatus-jimela-standing-on-a-termite-mound-maasai-53543801.html

https://www.alamy.com/topi-damaliscus-lunatus-standing-on-a-termite-mound-damaliscus-lunatus-maasai-mara-national-reserve-kenya-image263195575.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/a-topi-damaliscus-lunatus-standing-on-a-termite-mound-masai-mara-national-reserve-kenya-image448055827.html

https://www.alamy.com/stock-photo-a-topi-standing-on-a-termite-mound-to-claim-territory-in-kenya-the-34769972.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-topi-gazelle-stands-guard-on-a-termite-mound-in-the-vast-expanse-of-the-kenyan-savannah-image359157220.html

https://www.alamy.com/stock-photo-male-topi-on-termite-mound-masai-mara-national-reserve-kenya-12109542.html

https://www.alamy.com/topi-damaliscus-korrigum-damaliscus-lunatus-territorial-male-standing-alert-on-mound-masai-mara-game-reserve-kenya-image263046476.html

https://www.alamy.com/stock-photo-a-topi-standing-on-a-termite-mound-surveying-the-african-landscape-15012216.html

https://www.alamy.com/stock-photo-topi-damaliscus-lunatus-standing-on-a-termite-mound-masai-mara-kenya-43399300.html

https://www.alamy.com/a-topi-damaliscus-lunatus-standing-on-a-termite-mound-masai-mara-national-reserve-kenya-image448055806.html

https://www.alamy.com/a-male-topi-standing-guard-on-mound-image4450576.html

https://www.alamy.com/the-topi-damaliscus-lunatus-standing-upright-on-a-termite-mound-on-image5221751.html

https://www.alamy.com/stock-photo-topi-damaliscus-korrigum-adult-on-termite-hill-masai-mara-park-in-111495256.html

https://www.alamy.com/antelope-topi-is-standing-on-the-termite-mound-in-serengeti-national-park-tanzania-africa-image365229941.html

https://www.alamy.com/stock-photo-a-topi-standing-on-a-termite-mound-surveying-the-african-landscape-15012248.html

https://www.alamy.com/stock-photo-topi-damaliscus-lunatus-standing-on-a-termite-mound-masai-mara-kenya-43399308.html

https://www.alamy.com/the-topi-damaliscus-lunatus-standing-upright-on-a-termite-mound-on-image5221760.html

https://www.alamy.com/the-topi-damaliscus-lunatus-standing-upright-on-a-termite-mound-on-image5221744.html

https://www.agefotostock.com/age/en/details-photo/male-topi-damaliscus-lunatus-topi-standing-on-top-of-termite-mound-to-mark-his-territory-masai-mara-kenya/D17-274964

https://www.istockphoto.com/photo/topi-standing-guard-gm943155894-257723335?phrase=topi%20antelope%20on%20termite%20mounds%20masai%20mara%20kenya

https://www.istockphoto.com/photo/topi-watch-out-standing-on-old-termite-hill-gm155965859-22003741?phrase=topi%20antelope%20on%20termite%20mounds%20masai%20mara%20kenya

https://www.istockphoto.com/photo/topi-on-a-termite-hill-masai-mara-national-park-kenia-gm185267065-20000081?phrase=topi%20antelope%20on%20termite%20mounds%20masai%20mara%20kenya

JUVENILE MALES

https://www.inaturalist.org/observations/106517990

https://www.alamy.com/stock-photo-topi-damaliscus-korrigum-standing-guard-on-termite-mound-masai-mara-29928990.html

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/stock-photo-topi-damaliscus-lunatus-jimela-standing-on-a-termite-mound-maasai-53543872.html

https://www.alamy.com/two-topi-antelopes-damaliscus-lunatus-jimela-in-typical-lookout-mode-standing-on-termite-mound-in-masai-mara-kenya-africa-image178069583.html

https://www.alamy.com/male-topi-stands-on-sunny-termite-mound-image349041446.html

https://www.alamy.com/stock-photo-tsessebe-or-sassaby-damaliscus-lunatus-jimela-standing-in-a-typical-59213709.html

https://www.alamy.com/stock-photo-topi-damaliscus-lunatus-jimela-standing-on-a-termite-mound-maasai-53543900.html

https://www.alamy.com/stock-photo-africa-kenya-topi-damaliscus-korrigum-standing-on-termite-mound-29928670.html

https://www.alamy.com/stock-photo-topi-on-termite-mound-masai-mara-national-reserve-kenya-12109286.html

https://www.alamy.com/stock-photo-topi-damaliscus-lunatus-jimela-standing-on-a-termite-mound-maasai-53543879.html

https://www.alamy.com/stock-photo-topi-damaliscus-korrigum-standing-guard-on-termite-mound-masai-mara-29928873.html

https://www.alamy.com/stock-photo-topi-damaliscus-lunatus-jimela-standing-on-a-termite-mound-maasai-53543845.html

https://www.alamy.com/stock-photo-topi-damaliscus-lunatus-jimela-standing-on-a-termite-mound-maasai-53543902.html

https://www.alamy.com/stock-photo-topi-damaliscus-lunatus-jimela-standing-on-a-termite-mound-maasai-26007162.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/two-topi-in-the-serengeti-standing-on-termite-mound-royalty-free-image/1153456877

https://www.mindenpictures.com/stock-photo/topi-(damaliscus-lunatus)-guard-standing-on-termite-mound-masai-mara-national/search/detail-0_00763126.html

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.agefotostock.com/age/en/details-photo/topi-damaliscus-lunatus-mother-standing-on-termite-mound-with-baby-in-the-masai-mara-game-reserve-kenya/AAM-AAES70722

https://www.stevebloom.com/index.php?page=single&id=511097-BS1

https://www.istockphoto.com/photo/topi-antelopes-on-a-termite-hill-masai-mara-kenya-gm183834648-16408606?phrase=topi%20antelope%20on%20termite%20mounds%20masai%20mara%20kenya

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#.

Posted on October 20, 2022 05:34 AM by milewski