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

@muir @matthewinabinett @aguilita @tonyrebelo @jeremygilmore @beartracker @nyoni-pete @oviscanadensis_connerties @tandala @capracornelius @paradoxornithidae @wjcrins @hereinthewild @bluewhalenowhead @marshall20 @nat_zouieva @marina_gorbunova @simontonge

At first sight, Alces alces seems nondescript in colouration (https://www.inaturalist.org/observations/19029155 and https://www.inaturalist.org/observations/4336204).

Valerius Geist, on pages 229-232 in Grzimek's Animal Life Encyclopedia (https://en.wikipedia.org/wiki/Grzimek%27s_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 face tends to be paler than the neck and torso, in females of A. alces in North America (https://www.inaturalist.org/observations/178372818 and https://www.dreamstime.com/bull-moose-water-image259482733 and https://www.inaturalist.org/observations/8288949) and to some degree also in Europe (https://www.inaturalist.org/observations/175016790 and https://www.inaturalist.org/observations/174910182).

However, the difference in tone between the face and the rest of the figure is noticeable only in A. a. americana (see details in comment below, titled FACIAL FLAG IN ALCES ALCES AMERICANA).

Sexual differences in the colouration of the pelage of A. alces, beyond the face, are remarkably limited (https://www.inaturalist.org/observations/42138516 and https://www.youtube.com/watch?v=bujmogxgtp4 and https://www.youtube.com/watch?v=tsZUaGIt-r8 and https://www.google.com.au/search?q=Moose+mating&sca_esv=567242663&sxsrf=AM9HkKnsy5ar25NAM_QxNryBAc4ELWtrPA%3A1695294882706&source=hp&ei=oiUMZd3UJtixoATxmJzQAg&iflsig=AO6bgOgAAAAAZQwzssn9atv3I45ihgDieVv4Z3QxBVPr&ved=0ahUKEwjdrZPKybuBAxXYGIgKHXEMByoQ4dUDCAs&uact=5&oq=Moose+mating&gs_lp=Egdnd3Mtd2l6IgxNb29zZSBtYXRpbmcyBRAuGIAEMgUQABiABDIFEAAYgAQyBRAAGIAEMgUQABiABDIFEAAYgAQyBRAAGIAEMgUQABiABDIFEAAYgARImklQzg5Y-j5wAXgAkAEAmAGuA6AB_BiqAQkwLjEuOS4xLjG4AQPIAQD4AQGoAgrCAgcQIxjqAhgnwgIEECMYJ8ICCxAAGIAEGLEDGIMBwgIREC4YgAQYsQMYgwEYxwEY0QPCAgsQLhiDARixAxiABMICCxAAGIoFGLEDGIMBwgIHECMYigUYJ8ICCBAuGIoFGJECwgIIEAAYgAQYsQPCAggQABiKBRiRAsICCxAuGIoFGLEDGJECwgILEC4YgAQYxwEYrwE&sclient=gws-wiz#fpstate=ive&vld=cid:25246631,vid:YvNAJLygu9w,st:0). Even in the case of the face, males retain the female colouration as long as the antlers are still in velvet (https://www.daveshowalter.com/photo/bull-moose-portrait/).

Infants, although noticeably paler than adults, have colouration so plain that it, too, is nondescript (https://www.inaturalist.org/observations/4097272).

Seasonal changes in colouration are limited. There is a single annual molt (https://www.inaturalist.org/observations/108839229 and https://www.inaturalist.org/observations/125310240 and https://www.inaturalist.org/observations/22740621 and https://www.inaturalist.org/observations/20313689) in spring/early summer. The pelage, after being worn and weathered for a year, fades somewhat (https://www.inaturalist.org/observations/8449050).

However, the pelage remains dark enough in winter to be conspicuous against snowy backgrounds, even at distance (https://www.inaturalist.org/observations/148799385 and https://www.inaturalist.org/observations/135953868).

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: https://www.inaturalist.org/observations/163382249.

Although these features are subtle, individually variable, and perhaps seasonally variable, most of them occur in most of the nine subspecies.

CORNUAL FLAG

The antlers of A. alces, borne seasonally by males, tend to be conspicuously pale on the upper (dorsal) surface, in the subspecies with the largest antlers (https://unsplash.com/photos/Du8sGaNHVMc).

The cornual flag is derived essentially from the natural paleness of dry bone (https://www.inaturalist.org/observations/127384241).

However, in A. a. gigas and presumably A. a. buturlini,

This makes the antlers conspicuous, even at distance (https://www.inaturalist.org/observations/4612251).

The cornual flag in A. gigas

Cornual flag in Alces alces gigas:
https://www.inaturalist.org/observations/183421987
https://www.mediastorehouse.com/nature-picture-library/danny-green/moose-bull-alces-alces-walking-forest-clearing-15316906.html
https://www.inaturalist.org/observations/183421709
https://www.inaturalist.org/observations/458438
https://create.vista.com/unlimited/stock-photos/314205726/stock-photo-alaska-yukon-bull-moose-autumn/
scroll in https://www.akwildlife.org/news/wildlife-contest-2022

Cornual flag in Alces alces andersoni:
https://www.inaturalist.org/observations/61216754
https://www.mediastorehouse.com.au/design-pics/animals/bull-moose-peter-lougheed-provincial-park-18135905.html

Possible cornual flag in Alces alces shirasi:
https://www.inaturalist.org/observations/147438040
https://www.gettyimages.com.au/detail/news-photo/bull-moose-stands-on-bunn-trail-near-the-gunflint-trail-news-photo/55992779?adppopup=true and https://www.gettyimages.com.au/detail/news-photo/bull-moose-walks-on-bunn-trail-near-the-gunflint-trail-news-photo/55992785?adppopup=true

Possible cornual flag in Alces alces americana:
https://www.inaturalist.org/observations/76513586
https://visitsunsetcountry.com/hunting/moose

Incipient cornual flag in Alces alces alces:
https://www.mediastorehouse.com.au/nature-picture-library/2009-highlights/moose-alces-alces-taiga-woodland-15260457.html

FIBULAR FLAG

https://www.inaturalist.org/observations/8660028
https://www.gettyimages.com.au/detail/news-photo/november-2020-saxony-moritzburg-last-week-thursday-the-500-news-photo/1229586037?adppopup=true
https://www.behance.net/gallery/99847037/Bull-Moose-Bearspaw-Alberta?tracking_source=search_projects_recommended|Bull+Moose
https://www.closertothewild.com/gallery/p/style-01-slgxj-738cj-bnn5s-3e26g-rewyc-36zgb
https://www.shutterstock.com/image-photo/winter-sunny-day-young-moose-cow-2125295291
https://www.dreamstime.com/stock-photography-bull-moose-image21621952
https://www.dreamstime.com/wet-cow-moose-standing-forest-image183436539
https://www.inaturalist.org/observations/139111514
https://www.inaturalist.org/observations/61913264
https://www.inaturalist.org/observations/134851345
https://www.alamy.com/moose-in-jasper-canada-image348236851.html?imageid=D433EBFE-8D95-490C-BEAE-57C59F4AD201&p=466062&pn=5&searchId=59e69530b8d11356f2f4edcf3f5ed079&searchtype=0
https://www.alamy.com/young-elk-age-about-one-year-male-on-the-edge-of-the-spring-forest-image259781936.html?imageid=A982D41F-5A22-489F-99A6-9C17CFE32440&p=270423&pn=7&searchId=17a6b40e8c8fbef3da4fa2fc3209a279&searchtype=0
https://www.inaturalist.org/observations/35513964
https://www.inaturalist.org/observations/137101323
https://www.alamy.com/stock-photo-bull-moose-in-sweden-147415246.html?imageid=EE970C0F-EFDB-4D8A-94DA-986ACC0035E4&p=141390&pn=1&searchId=773e4e372ef4503cec1f3e748077968c&searchtype=0

Please see https://www.inaturalist.org/journal/milewski/84573-a-new-feature-of-adaptive-colouration-in-ungulates-the-fibular-flag-part-2-alces-alces-cervidae#

The fibular flag is best-developed in the nominate subspecies, A. a. alces, of Europe and western Russia, in which it tends to extend to the inner surface of the buttock (https://www.inaturalist.org/observations/149814632) and/or the hock.

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 (https://www.inaturalist.org/observations/112176729).

PEDAL FLAG

A case can be made that A. alces possesses a pedal flag, in some individuals. This applies particularly to the nominate A. a. alces (https://www.inaturalist.org/observations/142224245 and https://www.inaturalist.org/observations/142020077).

This pedal flag consists of conspicuous pale on the 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 (https://www.alamy.com/stock-photo-bull-moose-crossing-the-road-denali-national-park-alaska-usa-29001311.html?imageid=984BF44C-2D52-4F90-BF1B-9372BC0185A4&p=29229&pn=1&searchId=acbc6be48e9684687a1dabcb59018a60&searchtype=0).

The fetlocks and pasterns themselves are not whitish (https://www.gettyimages.com.au/detail/news-photo/december-2022-sweden-%C3%B6ster-malma-a-bull-moose-stands-in-the-news-photo/1246124150?adppopup=true and https://www.gettyimages.com.au/detail/news-photo/december-2022-sweden-%C3%B6ster-malma-a-bull-moose-stands-in-the-news-photo/1246124213?adppopup=true and https://www.shutterstock.com/image-photo/front-split-hoofs-moose-standing-on-727556374 and https://www.inaturalist.org/observations/134620144 and https://www.inaturalist.org/observations/35655176 and https://www.inaturalist.org/observations/55865091), except in some individuals of the nominate A. a. alces (https://www.mostphotos.com/en-us/25919107/moose-or-european-elk-alces-alces-hooves).

A factor undermining the validity of a pedal flag in A. alces is that, for much of the year, the pale on the legs is inconspicuous against a background of snow (https://www.inaturalist.org/observations/42170238 and https://www.inaturalist.org/observations/143176855).

https://www.inaturalist.org/observations/51436631
https://www.inaturalist.org/observations/33064841
https://www.dreamstime.com/large-brown-black-bull-moose-standing-park-image193883277
https://www.dreamstime.com/stock-photo-moose-bull-elk-standing-road-image66248282

To the degree that the pedal flag is valid in A. alces, it is linked to, and subsidiary to, the fibular flag (https://www.inaturalist.org/observations/142257592). In A. a. alces, the joint pattern can perhaps be called a pedofibular flag.

ANTERIOR AURICULAR SEMET

Please see https://www.inaturalist.org/journal/milewski/55694-ten-best-illustrations-of-auricular-semets-in-deer#

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 (https://www.dreamstime.com/stock-photo-moose-north-america-elk-europe-alces-alces-largest-extant-species-deer-family-moose-distinguished-image50713041).

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. alces:
https://www.inaturalist.org/observations/122347911
https://www.inaturalist.org/observations/119099452

A. a. americana:
https://www.inaturalist.org/observations/183781173
https://www.inaturalist.org/observations/165912205
https://www.inaturalist.org/observations/82792870

A. a. gigas:
https://www.inaturalist.org/observations/172965903
https://www.inaturalist.org/observations/15093287

A. a. andersoni:
https://www.inaturalist.org/observations/170210903
https://www.inaturalist.org/observations/166029819

A. a. shirasi:
https://www.inaturalist.org/observations/174251418

In Alces alces, unlike another large cervid partly sympatric with it, the auricular semet does not disappear in mature males (see https://colombia.inaturalist.org/journal/milewski/69281-intriguing-new-sexual-dimorphism-in-the-wapiti).

The following show that the anterior auricular semet, although absent in newborns, develops before the infantile colouration is lost, and before the muzzle develops:
https://www.inaturalist.org/observations/133091834
https://www.dreamstime.com/stock-photo-small-moose-few-days-standing-woods-next-to-pine-tree-image53403214.

BUCCAL SEMET

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 broadly dark lower lip is offset by pale ventral to the gape. The clearest illustration is https://www.inaturalist.org/observations/65908659.

The following are additional illustrations:
https://www.inaturalist.org/observations/152098783 and https://www.inaturalist.org/observations/148835598 and https://www.inaturalist.org/observations/13505171 and https://www.dreamstime.com/stock-photo-moose-eating-green-grass-near-water-grand-tetons-national-park-image50021650 and scroll to second photo in https://journals.openedition.org/paleo/5126 and https://www.inaturalist.org/observations/157638267 and https://www.inaturalist.org/observations/120152994 and https://www.inaturalist.org/observations/37290353 and https://www.inaturalist.org/observations/65278592 and https://www.inaturalist.org/observations/56223948 and https://www.inaturalist.org/observations/162881182.

This pattern of colouration hypothetically accentuates the chewing movements (https://www.inaturalist.org/observations/88438853). This hypothetically aids vigilance during rumination, when two or more adult/adolescent individuals rest within sight of each other (https://www.dreamstime.com/stock-photos-moose-image20463023).

Buccal semet in Alces alces buturlini:
https://www.alamy.com/female-moose-alces-alces-in-profile-kronotsky-zapovednik-nature-reserve-kamchatka-peninsula-russian-far-east-december-image263189582.html?imageid=8337E994-E81B-42C7-9D06-32050AEFBBE0&p=216449&pn=1&searchId=693543c6c0b82d61e979d27d23f7d17f&searchtype=0

Buccal semet in Alces alces gigas:
https://www.inaturalist.org/observations/153275621
https://www.inaturalist.org/observations/2646616
https://www.inaturalist.org/observations/13172080

Variation in this feature deserves further investigation. The pattern seems clearest in spring, when the worn, weathered pelage has faded but the dark on the lower lip has not faded (https://www.inaturalist.org/observations/5155147). The following shows the minimal expression of the buccal semet (https://www.inaturalist.org/observations/114831099), but it is unclear whether this is because of the summer season or individual variation.

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 (https://www.inaturalist.org/observations/29864809 and https://www.123rf.com/photo_188787653_portrait-of-a-walking-cow-moose-and-her-calf-alces-alces.html and https://www.inaturalist.org/observations/7440096).

Posted on Σεπτέμβριος 19, 2023 1246 ΠΜ by milewski milewski

Σχόλια

Αναρτήθηκε από milewski 2 μήνες πριν
Αναρτήθηκε από milewski 2 μήνες πριν
Αναρτήθηκε από milewski 2 μήνες πριν

Fibular flag and anterior auricular semet in Alces alces shirasi:

https://www.inaturalist.org/observations/149570087

Αναρτήθηκε από milewski 2 μήνες πριν
Αναρτήθηκε από milewski 2 μήνες πριν
Αναρτήθηκε από milewski 2 μήνες πριν

The withers tend to be pale, offset by the darkness of the short mane (https://www.alamy.com/cow-moose-feeding-48-image3090722.html?imageid=C50F6C04-892C-4860-A68F-4E654C45722E&p=166893&pn=1&searchId=f41a66b0ac6853a16f070809256f1de5&searchtype=0 and https://www.dreamstime.com/royalty-free-stock-photos-large-moose-field-rocky-mountain-national-park-image40381468 and https://www.dreamstime.com/stock-photo-moose-bull-alaska-usa-standing-fall-colour-meadow-lone-image78127514 and https://www.inaturalist.org/observations/214913).

However, this pattern is never graphic enough, in any subspecies/individual, to warrant a name. Furthermore, it is disrupted by the weathering, fading, and molt of the pelage, more than any other aspect of colouration (https://www.inaturalist.org/observations/76352986).

It is perhaps surprising that the dewlap of Alces alces lacks conspicuous colouration (https://www.inaturalist.org/observations/35801756).

Αναρτήθηκε από milewski 2 μήνες πριν
Αναρτήθηκε από milewski 2 μήνες πριν

Weren't the American subspecies recognised as a separate species a while back?

Αναρτήθηκε από paradoxornithidae 2 μήνες πριν

@paradoxornithidae

Valerius Geist regarded Alces as consisting of two 'types', one of which occurs in North America plus eastern Asia - intriguingly including the small form, cameloides, of Manchuria (https://en.wikipedia.org/wiki/Manchuria) and Ussuri (https://en.wikipedia.org/wiki/Ussuri).

Αναρτήθηκε από milewski 2 μήνες πριν

Very interesting!

Αναρτήθηκε από beartracker 2 μήνες πριν
Αναρτήθηκε από milewski 2 μήνες πριν

The following series of photos of Alces alces in trotting gait show the variation in colouration in the inner (medial) and outer (lateral) surfaces of the legs:

https://www.inaturalist.org/observations/186569084

https://www.inaturalist.org/observations/58902436

https://calgaryherald.com/news/local-news/police-advise-calgarians-not-to-take-selfies-with-moose-on-the-loose

https://www.alamy.com/stock-photo-swedish-moose-in-wintertime-55501239.html?imageid=0F0E2218-DDBC-4B62-8F6C-21D8066C669E&p=151393&pn=1&searchId=f65e2a0a9708d789f87bce31220c7acf&searchtype=0

https://www.alamy.com/two-moose-alces-alces-running-over-a-filed-adult-and-a-calf-in-winter-season-norrbotten-province-sweden-image370684093.html?imageid=DF938710-87C9-4121-B7C4-612027F3A454&p=219762&pn=1&searchId=f65e2a0a9708d789f87bce31220c7acf&searchtype=0

https://www.alamy.com/two-moose-alces-alces-running-over-a-filed-adult-and-a-calf-in-winter-season-norrbotten-province-sweden-image370684324.html?imageid=0075AB6A-EEFE-40DF-B267-F015FBC6F80C&p=219762&pn=1&searchId=f65e2a0a9708d789f87bce31220c7acf&searchtype=0

https://www.alamy.com/stock-photo-moose-running-in-winter-canada-24725564.html?imageid=01133AD9-45A0-4CE7-A9BF-2E38D56F9B88&p=38999&pn=2&searchId=38f901d668948e8466cd403d76ae2a75&searchtype=0

https://www.alamy.com/stock-photo-european-moose-alces-alces-alces-adult-female-running-on-snow-covered-87948980.html?imageid=DFAB6F5C-1753-45EF-8388-300EDF4A0882&p=11592&pn=5&searchId=59e69530b8d11356f2f4edcf3f5ed079&searchtype=0

https://www.inaturalist.org/observations/14970153

https://depositphotos.com/photo/mother-moose-trotting-snow-sunny-winter-day-sweden-same-posiyion-534546262.html

https://www.inaturalist.org/observations/47020098

https://www.inaturalist.org/observations/156465235

https://www.inaturalist.org/observations/79368002

Αναρτήθηκε από milewski 2 μήνες πριν

@paradoxornithidae @matthewinabinett

FACIAL FLAG IN ALCES ALCES AMERICANA

In Alces alces americana of eastern North America, the face tends to be so much paler than the neck and body that this may be an adaptively conspicuous feature.

The process producing this pattern is that the face remains the same colour from birth to adulthood (https://www.inaturalist.org/observations/17977223).

Adult females:
https://www.inaturalist.org/observations/142465055
https://www.inaturalist.org/observations/179559464
https://www.inaturalist.org/observations/118515802
https://www.inaturalist.org/observations/124116989
https://www.inaturalist.org/observations/199608
https://www.inaturalist.org/observations/45187191

Adult males in velvet:
https://www.inaturalist.org/observations/123975329
https://www.inaturalist.org/observations/84065039
https://www.inaturalist.org/observations/28139945

In adult males in hard antler, the rostrum turns dark:
https://www.inaturalist.org/observations/35566678
https://www.inaturalist.org/observations/63784099
https://www.inaturalist.org/observations/36022489

The paleness of the face in A. a. americana does not detract from the validity of the anterior auricular flag:
https://www.inaturalist.org/observations/17219200

The facial flag does not categorically distinguish subspecies americana, because even in the far west of Russia some individuals (of the nominate subspecies, alces) show similar colouration (https://www.inaturalist.org/observations/173995526).

Αναρτήθηκε από milewski 2 μήνες πριν

Adult female of Alces alces americana in autumn:

https://www.inaturalist.org/observations/20543805

Alces alces americana at the stage when the infantile colouration is lost:

https://www.inaturalist.org/observations/30180306

Αναρτήθηκε από milewski 2 μήνες πριν
Αναρτήθηκε από milewski 2 μήνες πριν
Αναρτήθηκε από milewski 2 μήνες πριν
Αναρτήθηκε από milewski 2 μήνες πριν

DETAILS OF SEXUAL DIMORPHISM IN COLOURATION OF PELAGE

The following individual of Alces alces shirasi is an exception to the rule that the pelage of the rostrum of the face turns dark once the antlers turn hard, each year:

https://www.dreamstime.com/close-up-portrait-bull-moose-turnbull-wildlife-refige-cheney-washington-bull-moose-forest-image196149858

The following is a converse exception, in which the rostrum is already dark, despite the antlers still being in velvet:

https://www.alamy.com/stock-photo-moose-alces-alces-bull-with-antlers-covered-in-velvet-lying-in-grassland-104911328.html?imageid=617EA6AA-340E-49D8-9BB2-C5BA285658E0&p=80871&pn=1&searchId=01a194e512fe373b644556296ed315c3&searchtype=0

The following shows that the rostrum remains dark after the antlers are shed, in winter:

https://www.alamy.com/stock-photo-moose-elk-alces-alces-close-up-of-bull-showing-pedicel-scars-left-96453235.html?imageid=DCCDD2BA-6897-46C8-9B4F-1374B552F700&p=80871&pn=1&searchId=01a194e512fe373b644556296ed315c3&searchtype=0

Αναρτήθηκε από milewski 2 μήνες πριν
Αναρτήθηκε από milewski 2 μήνες πριν

Buccal semet in Taurotragus oryx, which shares the name 'eland' with Alces alces:

https://www.pexels.com/photo/brown-antelope-lying-on-ground-5591913/

Αναρτήθηκε από milewski 2 μήνες πριν

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