Subspecies of the moose (Alces alces) turn out to be too nebulous to identify from photographs

@muir @matthewinabinett @aguilita @tonyrebelo @jeremygilmore @beartracker @nyoni-pete @oviscanadensis_connerties @tandala @capracornelius @paradoxornithidae @wjcrins @hereinthewild @bluewhalenowhead @marshall20 @nat_zouieva @marina_gorbunova @simontonge @michalsloviak @chewitt1 @maxallen @calebcatto @jwidness @bobby23

Also see:

https://www.inaturalist.org/journal/milewski/84595-adaptive-colouration-in-the-largest-living-cervid-the-moose-alces-alces#

https://www.researchgate.net/publication/272744329_Evolution_of_a_rump_patch_in_Alaskan_moose_an_hypothesis

https://www.researchgate.net/profile/R-Bowyer/publication/272818592_Moose_Alces_alces/links/54ef7d600cf25f74d7227c51/Moose-Alces-alces.pdf

There are currently so many thousands of photos of Alces alces on the Web, particularly in iNaturalist (https://www.inaturalist.org/taxa/522193-Alces-alces), that it has taken me weeks to go through most of them.

However, remarkably few are labelled as to subspecies.

This seems to be mainly because available information on the Web, on the differences in appearance among the nine subspecies, is scant and confusing.

So, I have devoted several weeks to compiling a photo-guide to the subspecies.

I have failed.

The reasons for my failure are, in decreasing order of importance,

• each population shows excessive variation in colouration among individuals,
• the colouration is so nondescript/nebulous that even any 'typical' colouration is hard to find, for any subspecies,
• there are few, if any, clear photos for several subspecies, namely caucasicus (extinct), cameloides and buturlini (remote), and pfizenmayeri (extremely remote),
• variation seems to be clinal longitudinally, from Europe through Asia and Beringea to eastern North America, and
• the colouration is disrupted by the annual cycle of molt of the pelage.

There is certainly considerable variation in body size among subspecies, with gigas and buturlini largest, and cameloides and shirasi smallest.

There is also obvious variation in the proportional size of the antlers, corresponding partly to body size - with gigas and buturlini possessing the largest antlers, and cameloides and nominate alces the smallest.

However, these variations in size are not necessarily diagnostic of subspecies, because

• females lack antlers,
• the size of the antlers varies greatly according to age and nutritional status, and
• body size, and partly the maximum size of the antlers, can be interpreted as ecotypical rather than genetic, mainly according to Bergmann's rule (https://en.wikipedia.org/wiki/Bergmann%27s_rule and https://link.springer.com/article/10.1007/bf00341355).

There is scant sexual dimorphism in the colouration of the pelage, in A. alces. The main feature distinguishing males is the darkness of the rostrum (https://www.gettyimages.com.au/detail/photo/moose-bull-with-antlers-chugach-state-park-alaska-royalty-free-image/104336075?phrase=bull+moose&adppopup=true), and even this appears only in autumn and winter, when the antlers are hard. I.e. as long as the antlers are still in velvet, the rostrum remains the same medium tone as in females (https://www.gettyimages.com.au/detail/photo/wildlife-in-wyoming-morning-moose-too-royalty-free-image/865860394?phrase=bull+moose&adppopup=true).

My perusal of tens of thousands of photos has produced the following as the clearest depictions of each putative subspecies.

ALCES

https://www.inaturalist.org/observations/48543915
https://www.inaturalist.org/observations/74824385
https://www.inaturalist.org/observations/40353294
https://www.inaturalist.org/observations/40295954
https://www.inaturalist.org/observations/36579437
https://www.inaturalist.org/observations/107471426

PFIZENMAYERI

https://www.inaturalist.org/observations/154930634
https://www.inaturalist.org/observations/99207826

CAMELOIDES

https://www.inaturalist.org/observations/100833248

BUTURLINI

no clear photos found

GIGAS

https://www.inaturalist.org/observations/19029155
https://www.inaturalist.org/observations/4336204
https://www.gettyimages.com.au/detail/photo/bull-moose-standing-on-paved-road-royalty-free-image/657485904?phrase=bull+moose&adppopup=true
https://www.alamy.com/stock-photo-moose-alces-alces-gigas-bull-shedding-velvet-in-fall-colour-denali-43929349.html?imageid=B7C5FC8C-124E-45F2-8F36-BBECD7DF7619&p=82357&pn=1&searchId=acbc6be48e9684687a1dabcb59018a60&searchtype=0
https://www.alamy.com/stock-photo-moose-alces-alces-gigas-bull-shedding-velvet-in-fall-colour-denali-43929346.html?imageid=7FE5B5FD-8DD8-41F7-B30B-56A0F3B06FA5&p=82357&pn=1&searchId=acbc6be48e9684687a1dabcb59018a60&searchtype=0
https://www.alamy.com/large-bull-moose-alces-alces-standing-in-brush-near-powerline-pass-in-the-chugach-state-park-near-anchorage-in-south-central-alaska-on-a-sunny-a-image262218511.html?imageid=74278539-3205-4823-8AD0-46EFF7A6FB65&p=865240&pn=2&searchId=554d1410ca2b2a81e85b649c9589dd49&searchtype=0
https://create.vista.com/unlimited/stock-photos/343027438/stock-photo-cow-alaska-yukon-moose-denali-national-park-autumn/
https://www.flickr.com/photos/richardmcguire/27569540250
https://create.vista.com/unlimited/stock-photos/321158754/stock-photo-alaska-yukon-bull-moose-denali-national-park-alaska-autumn/
https://create.vista.com/unlimited/stock-photos/403606204/stock-photo-alaska-yukon-bull-moose-autumn/
https://create.vista.com/unlimited/stock-photos/347164868/stock-photo-alaska-yukon-bull-moose-autumn-denali-national-ark/
https://www.alamy.com/stock-photo-bull-moose-in-rut-near-powerline-pass-in-chugach-state-park-with-the-37569209.html?imageid=45F0C1B5-ABCD-4D02-9CE7-F9CA3C24FA8E&p=228600&pn=1&searchId=acbc6be48e9684687a1dabcb59018a60&searchtype=0
https://www.alamy.com/stock-photo-a-large-bull-moose-near-jewel-lake-road-in-anchorage-southcentral-125340208.html?imageid=9FBF37D1-13CB-4243-ADC6-9AA1AB5E2564&p=228198&pn=2&searchId=34e410ab9894add09ba6f8a15ae051be&searchtype=0

ANDERSONI

https://www.inaturalist.org/observations/34440227
https://pngtree.com/freebackground/bull-moose-alberta-national-moose-meadow-photo_4533013.html
https://www.inaturalist.org/observations/136606221
https://www.inaturalist.org/observations/24376876
https://www.inaturalist.org/observations/124213587
https://www.inaturalist.org/observations/87482894
https://www.inaturalist.org/observations/59045574
https://www.inaturalist.org/observations/50346121
https://www.inaturalist.org/observations/142792524
https://www.inaturalist.org/observations/97397248
https://www.agefotostock.com/age/en/details-photo/big-bull-moose-alces-alces-in-alberta-canada/ACX-acp82420

SHIRASI

scroll to second photo in https://yellowstone.net/wildlife/moose/
https://www.shutterstock.com/image-photo/bull-moose-38346343
https://www.shutterstock.com/image-photo/bull-moose-38346340
https://www.dreamstime.com/moose-grand-teton-national-park-moose-grand-teton-national-park-wyoming-fall-mating-season-rut-september-image245496137
https://www.dreamstime.com/moose-grand-teton-national-park-wyoming-fall-mating-season-rut-september-october-moose-grand-teton-image245496154
https://depositphotos.com/photo/bull-cow-moose-rutting-wyoming-autumn-654387068.html
https://dailywildlifephoto.nathab.com/photos/3853-mother-daughter-10-16-2016

AMERICANA

https://www.inaturalist.org/observations/106180210
https://www.inaturalist.org/observations/199608
https://zoo-world-builder.fandom.com/wiki/Eastern_Moose?file=Moose.jpg
https://www.inaturalist.org/observations/175626629
https://www.inaturalist.org/observations/170927798
https://www.inaturalist.org/observations/55865091
https://www.inaturalist.org/observations/35655176

DISCUSSION

Any subspecific distinctions are quantitative, the various populations overlapping broadly in features. No subspecies shows any categorically distinct feature, and every subspecies shows much individual variation.

Alces alces gigas, restricted to Alaska and western Yukon, seems to be distinctive enough to warrant its subspecific status (https://en.wikipedia.org/wiki/Alaska_moose).

This is because

• it has the greatest number of clear photos, of any population,
• it has extremely large body and antlers,
• it inhabits tundra as much as coniferous forest, with corresponding sociality, and
• it has a reputation for relatively graphic colouration on the haunches (https://www.researchgate.net/publication/272744329_Evolution_of_a_rump_patch_in_Alaskan_moose_an_hypothesis).

Photos bear out the fact that, in A. a. gigas, the withers (pale), rest of torso (medium), and haunches (dark) tend towards a three-toned pattern. The antlers are indeed proportionately large, and conspicuously pale (noticeably mainly in September)

However, I question the subspecific status of even A. a. gigas. This is because

• its phenotype does not necessarily correspond to a distinctive genotype, and
• the tonal differentiation on withers, torso, and haunches also occurs in other regions, including faraway Europe, on an individual basis.

Alces alces is an extremely recent species, evolutionarily, having arisen within the timespan and the zone of influence of the modern human species. It is, in a sense, an anthropogenic species and perhaps even genus, possessing the extreme versatility of foraging, and the extreme fecundity, needed to survive predation by Homo sapiens.

I would not go as far as to suggest that all subspecies of A. alces are invalid. This is because

• populations in western Europe have reached a distance of 18,000 km from those in eastern Canada, and
• pale pelage on the legs certainly tends to be expressed more in Europe than in North America - indicating at least a geographical (circum-subpolar) cline.

However, I now know that - despite my best efforts - I remain unable to identify any subspecies from its appearance in photos, as opposed to from its location and context.

If subspecies are valid and are expressed phenotypically, then the best that can be said is that they involve different probabilities in a shared spectrum of features of antler-form and colouration (particularly on the legs).

Publicado el 23 de septiembre de 2023 a las 03:19 AM por milewski