Adaptive colouration in the largest living cervid, the moose (Alces alces)

@muir @matthewinabinett @aguilita @tonyrebelo @jeremygilmore @beartracker

At first sight, Alces alces seems nondescript in colouration ( and

Valerius Geist, on pages 229-232 in Grzimek's Animal Life Encyclopedia (, exaggerates somewhat when he states:
"European moose are dark brown with white legs, and American moose are black with a light saddle patch on the back, light-brown legs, and facial markings that vary between the sexes. In the female the face and nose are red-brown, while the bull has a black nose".

The following verify that the head tends to be paler than the neck and torso, in females of A. alces in North America ( and However, this applies to some degree also in Europe ( and

Overall, sexual differences in the colouration of the pelage of A. alces are remarkably limited ( and and,vid:YvNAJLygu9w,st:0).

Infants, although noticeably paler than adults, have colouration so plain that it, too, is nondescript (

Seasonal changes in colouration are limited, resulting from the single annual molt in spring/early summer. In winter, the pelage remains dark enough to be conspicuous against snowy backgrounds, even at distance ( and

Despite the initial nondescript impression, my close scrutiny has revealed several noteworthy patterns of colouration, which deserve names, in A alces.

For example, the following shows a fibular flag, anterior auricular semet, and buccal semet in an adolescent female individual in the spring season, in Alces alces gigas:

Although these features are subtle, individually variable, and perhaps seasonally variable, they seem fairly consistent among the various subspecies.


The antlers of A. alces, borne seasonally by males, tend to be conspicuously pale on the upper (dorsal) surface. This is noticeable only innthe subspecies with the largest antlers

The cornual flag is derived essentially from the natural paleness of dry bone (

However, in A. alces,

This makes the antlers conspicuous, even at distance (, particularly in A. a. gigas and (presumably) A. a. buturlini.

The cornual flag in A. gigas

  • is apparent mainly in autumn, and
  • hypothetically functions intraspecifically, aiding sexual attraction, male advertisement, and masculine rivalry.

Cornual flag in Alces alces gigas:

Cornual flag in Alces alces shirasi:


Please see

The fibular flag is best-developed in the nominate subspecies, A. a. alces, of Europe and western Russia.

The role of sheen deserves investigation.

The following shows the extreme development of the pale pelage in A. alces, in which it encompasses most of the hindleg (


A case can be made that A. alces possesses a pedal flag, in some individuals. This applies particularly to the nominate A. a. alces.

This pedal flag consists of conspicuous pale on hocks and carpals (particularly on the posterior surface of the carpals), extending to varying extent down the lower limbs towards the hooves, and connected to the fibular flag where the latter is present. The fetlocks and pasterns themselves tend not to be whitish (, except in the nominate A. a. alces.

To the degree that the pedal flag is valid in A. alces, it is linked to, and subsidiary to, the fibular flag.


Please see

One of the most consistent patterns of colouration in A. alces is a small-scale dark/pale contrast on the anterior base of the ear pinna (

The location of this pattern is such that it accentuates the movements of the ears, in vigilance and emotional expression. Such accentuation is hypothetically adaptive in social (intraspecific) interactions, and may additionally function in anti-predator, defensive displays.

Several other genera of cervids possess auricular semets. However, that of A. alces is restricted to the anterior surface, and has its own particular configuration.

The following show the anterior auricular semet in various subspecies of A. alces:

A. a. americana:

A. a. gigas:

A. a. andersoni:

A. a. shirasi:

The following show that the anterior auricular flag, although absent in newborns, develops before the infantile colouration is lost, and before the muzzle develops:


The peculiar muzzle of A. alces is so distracting that the colouration around the mouth may go unnoticed. Furthermore, this colouration is subtle and individually variable.

However, there tends to be a pattern in which the dark chin and lower lip are offset by pale ventral to the gape ( and and and

This hypothetically accentuates the chewing movements of rumination, thus aiding vigilance where two or more adult/adolescent individuals are within sight of each other while resting (

Buccal semet in Alces alces buturlini:

Buccal semet in Alces alces gigas:

Variation in this feature deserves further investigation. The pattern seems clearest in spring. The following, taken in summer, shows its minimal expression (

Of all the features described here, the buccal semet is the most precocial, in the sense that the lower lip is dark even in infants (

Publicado el 19 de septiembre de 2023 00:46 por milewski milewski


Fibular flag and anterior auricular semet in Alces alces shirasi:

Publicado por milewski hace 2 días

The withers tend to be pale, offset by the darkness of the short mane ( and and However, this pattern is never graphic enough, in any subspecies/individual, to warrant a name.

It is perhaps surprising that the dewlap of Alces alces lacks conspicuous colouration (

Publicado por milewski hace 2 días
Publicado por milewski hace alrededor de 7 horas

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