Adaptive colouration in the tsessebe (Damaliscus lunatus lunatus), using the related blesbok for reference

The tsessebe (Damaliscus lunatus lunatus, has inconspicuous colouration ( and

This is true also for the colouration of infants, which differs from that of adults ( and and

However, in some illuminations, adults can be conspicuously dark:

And in others, parts of the hindquarters can gleam conspicuously pale:

This variation seems to be partly owing to sheen/anti-sheen effects (

In this Post, my approach is to compare D. lunatus lunatus with its congener, the blesbok (Damaliscus pygargus phillipsi). This has the advantage of setting search-images for various features of colouration.

My reference for ageing criteria is and


Both the blesbok and the tsessebe have sheeny, pale pelage on the hindquarters, particularly the uppermost, innermost buttocks.

Both thus possess flags, that of the tsessebe being the more nebulous.

However, the difference in the patterns means that the blesbok possesses a pygal flag (with an extension on to the ischial surface), whereas the tsessebe possesses an ischial flag (with an extension in to the pygal surface).

The blesbok and the tsessebe share a definite dark/pale pattern on the posterior surface of the upper foreleg. In the case of the blesbok, this consists of medium-dark tone vs white, whereas in the tsessebe it consists of dark vs medium-pale tone.

Although the patterns are homologous, that of the blesbok qualifies as an ulnar flag, whereas that of the tsessebe does not. The maximum conspicuousness' in the case of the tsessebe is shown in However, this is not typical.

What this means is that the tsessebe possesses what is a residual/incipient version of the ulnar flag of the blesbok.

Blesbok and and and and and and and and and

Tsessebe and and and and and and and and and


The blesbok possesses an abdominal flag, consisting of whitish pelage on the lower, posterior flanks adjacent to the knee. By contrast, the tsessebe lacks this feature.

Blesbok and

Tsessebe and and and and


The blesbok possesses a pedal flag, consisting of whitish on the lower legs, particularly the inner surface of the lower foreleg. By contrast, the tsessebe lacks this feature, because the lower legs, although clear in their pattern, are not pale enough to be conspicuous even when in motion.

Blesbok and and

Tsessebe and and and and and
and and and


Blesbok and and and and

Tsessebe and and


In adults of the tsessebe, both the rostrum and the centre of the forehead have consistently dark pelage.

The pattern follows that of the pale rostrum and forehead of the blesbok, apart from the facts that the dark in the tsessebe does not reach the rhinarium, and is not constricted just above eye-level.

The major difference is that the dark on the face of the tsessebe does not qualify as either a facial bleeze or a facial flag. This is because of

  • a lack of dark/pale contrast,
  • the glossiness of the pigmented pelage, which diminishes the darkness in bright sunlight, and
  • the much smaller size of the head and rostrum, relative to the body, in the tsessebe than in the blesbok.

In both the blesbok and the tsessebe, the anterior surface of the ear pinnae has whitish hairs, which can be somewhat conspicuous at certain distances and in certain illuminations (

However, a major difference is that the blesbok has sheeny pale on the posterior surface of the ear pinnae, constituting an auricular flag. In the tsessebe, this auricular flag is categorically absent, because the pelage on the back-of-ear is not pale in any illumination.

Blesbok and

Tsessebe and and and and and

In some individuals of the tsessebe, there is a faint dark streak on the temple and posterior to the eye (first photo in This is homologous with the pale streak seen in juveniles and adolescents of the blesbok ( However, in the tsessebe its adaptive significance is questionable.

Unlike the blesbok, the tsessebe adorns its horns and face with mud ( and and and and and and and and


Please see


In both the blesbok and the tsessebe, infants differ from adults in colouration, being fawn with countershading, with the dark tail-tassel merely incipient. (Please note that the tail-tassels have different shapes, already at birth.)

However, three differences are that:

  • infants of the blesbok are slightly paler than those of the tsessebe, and the cheeks ( and inner surfaces of the lower forelegs of the former are actually whitish,
  • the tsessebe lacks the crisp border between pale on the cheeks and medium tone on the rostrum, and
  • the pale patch on the posterior surface of the upper foreleg is so poorly-developed in the tsessebe that it is hardly noticeable.

Blesbok and and and scroll in


1 week old

1 month old and and

1.5 month old and
and and

2.5 months old and


In the blesbok, the facial colouration goes through a complex juvenile pattern which is transitional but not intermediate between the infantile and adult patterns.

In the tsessebe, this complexity is absent, and the patterns are simple and intermediate.

Also please see


3 months old and

4 months old

5 months old and

8 months old and


The tsessebe, although congeneric with the blesbok and lacking a mane, a beard, and a long tail-tassel, resembles wildebeests rather than the blesbok, in adaptive colouration.

The tsessebe, like the blesbok, has pelage showing sheen/antisheen effects. These effects are more important in the case of the tsessebe, which lacks any whitish pelage other than at a small-scale on the front-of-ear.

Evidence for some degree of adaptive conspicuousness, overall, in the tsessebe is the lack of countershading on the ventral surface of the torso in adults and juveniles. The effect - shared with all wildebeests - is that pigmentation and shading combine to produce dark emphasis of the ventral silhouette of the figure ( and and

However, the dark anti-sheen effect in Connochaetes gnou is not seen in the tsessebe ( and

Furthermore, the tsessebe does not appear as dark as Connochaetes taurinus mattosi, when viewed in the same illumination (

The adornment of the face with mud by the tsessebe is consistent with the small size of the horns, and the lack of a conspicuous pattern of colouration on the face.

In the tsessebe, the tail is inconspicuous compared with those of other alcelaphins. The tail-stalk is long but slender, and the tail-tassel is much smaller than in wildebeests (Connochaetes), and somewhat smaller than in hartebeests (Alcelaphus, and the blesbok.

In the closely related species, Damaliscus jimela, the tail is raised during proud-trotting, in masculine display ( Has this display been recorded in the tsessebe?

Infants of the tsessebe and the blesbok have a generic similarity. However, the difference is that the facial bleeze, ulnar flag, and pedal flag - features lacking in the tsessebe - are already incipient at birth in the blesbok.

For an index to my many Posts about the genus Damaliscus, please see

Publicado el 28 de marzo de 2023 09:35 por milewski milewski


Publicado por milewski hace 6 meses

@tonyrebelo @jeremygilmore

The following ( is stated to be from Namibia. If so, it seems that the bontebok, or more likely a hybrid between the blesbok and the bontebok, has been imported into Namibia by game farmers. Either way, the photo is misidentified on the Web.

Publicado por milewski hace 6 meses

The relatively pale patch on the ulnar surface does not extend to the outer foreleg in the tsessebe (

Publicado por milewski hace 6 meses

Agree. It might be that it is easier legally to import Blesbok than Bontebok, and so they are sold and transported as Blesbok, and then featured as Bontebok later?

Publicado por tonyrebelo hace 6 meses


A picture worth a thousand words:

Publicado por milewski hace 6 meses

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