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

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

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 septiembre 23, 2023 03:19 MAÑANA por milewski milewski

Comentarios

Could they have enough genetic differences while being pretty similar in morphology? With how they migrate, distinct populations should have limited ability to mix between.

Publicado por marina_gorbunova hace 5 meses

@marina_gorbunova

Both genotype and phenotype are potentially important, in determining subspecific status.

However, genetic studies have yet to show clear genotypic differences, within Alces alces.

For subspecies to be convincingly demonstrated, we would need a) quantitative comparisons of the incidence of various features among populations (e.g. does whitish on the belly, seen fairly frequently in Europe, occur in even a few individuals in faraway eastern Canada?), and b) experiments testing phenotypic plasticity when reared in given environments (e.g. how large could cameloides grow if reared in the same climate, and given the same food, as gigas, and to what degree would the antlers be boosted?)

Is it possible that geographic variation in Alces alces is all ecotypical, and might it even be possible that the ecotypical variation is all phenotypic rather than genotypic? I do not know, and perhaps this is unknowable.

However, what I do know is:
If you give me a clear photo of an adult female, with the background hidden and the location withheld, the best I can do is to identify it according to a distinction between nominate alces/pfizenmayeri on one hand, and the rest of the subspecies on the other (as summarised by Geist decades ago). And even then, my average confidence would be no more than 70% (also please see comment below, titled 'WHITISH ON HINDLEGS')

Publicado por milewski hace 5 meses

@marina_gorbunova @matthewinabinett

WHITISH ON HINDLEGS

Most photos of Alces alces alces show whitish upper hindlegs (https://www.inaturalist.org/observations/157248660). This distinguishes the European and Russian populations from those in North America, where a) few photos show whitish hindlegs, and b) the whitish seldom extends to the anterior (tibial) surface of the upper hindleg.

This distinction, although obviously valid, corresponds not to subspecies, but to sets of subspecies. Furthermore, even in A. a. alces, some individuals (which I estimate to be about 10%) lack whitish on the hindlegs, as shown by the following photos:

https://www.inaturalist.org/observations/176993423

https://www.inaturalist.org/observations/177239862

https://www.inaturalist.org/observations/176472894

https://www.inaturalist.org/observations/176468192

https://www.inaturalist.org/observations/166445389

https://www.inaturalist.org/observations/166368409

https://www.inaturalist.org/observations/162934291

https://www.inaturalist.org/observations/149814010

https://www.inaturalist.org/observations/148926838

https://www.inaturalist.org/observations/146151938

https://www.inaturalist.org/observations/140811602

https://www.inaturalist.org/observations/136013020

https://www.inaturalist.org/observations/132593814

https://www.inaturalist.org/observations/132593456

https://www.inaturalist.org/observations/124364181

https://www.inaturalist.org/observations/126850540

https://www.inaturalist.org/observations/123342869

https://www.inaturalist.org/observations/121864763

https://www.inaturalist.org/observations/120700724

https://www.inaturalist.org/observations/120591052

https://www.inaturalist.org/observations/116925644

https://www.inaturalist.org/observations/97440252

https://www.inaturalist.org/observations/97160291

https://www.inaturalist.org/observations/94132921

https://www.inaturalist.org/observations/92553049

https://www.inaturalist.org/observations/85910868

https://www.inaturalist.org/observations/84222031

https://www.inaturalist.org/observations/48835414

https://www.inaturalist.org/observations/47902598

https://www.inaturalist.org/observations/47566468

https://www.inaturalist.org/observations/40354371

Publicado por milewski hace 5 meses

Interesting!

Publicado por muir hace 5 meses

Agregar un comentario

Acceder o Crear una cuenta para agregar comentarios.