Which is the smallest sexual organism?
(writing in progress)
Does any sexual organism complete its lifecycle in less than 24 hours?
(writing in progress)
Diario de milewski
01 de octubre de 2023
30 de septiembre de 2023
Variation in walking gaits in ungulates: why some hoofed mammals cross-walk, whereas others amble
@tonyrebelo @jeremygilmore @zarek @tandala @oviscanadensis_connerties @maxallen @davidbygott @paradoxornithidae @beartracker @aguilita @marcelo_aranda @dejong @saber_animal @botswanabugs @dinofelis
Ungulates are defined by their feet, which bear hooves. Given this pedal specialisation, one might expect all ungulates to walk with similar gaits.
But this is not the case.
In this Post, I classify, illustrate, and explain the walking gaits of ungulates, which vary considerably and in ways related to habitats and niches.
Let us begin by referring to one of the most relatable of non-ungulate mammals, similar in body size to fairly small ungulates, and sharing some of their habitats, viz. baboons (genus Papio).
Baboons provide a useful starting point because they are anthropoid primates, walking with a simple gait that the human observer can easily understand.
Baboons cross-walk, moving the legs approximately in diagonal pairs (https://www.youtube.com/watch?v=L9mSdjW0SRY and https://www.shutterstock.com/video/clip-1016965867-baboon-walking-on-road and https://www.storyblocks.com/video/stock/a-baboon-walks-through-the-grass-in-africa-rvzv5putliq9ns8jl and https://elements.envato.com/a-baboon-walking-EVQ5HP8).
Humans walk with a similar diagonal pattern of swinging the limbs, except that our bipedality means that our hands remain off the ground (https://www.youtube.com/watch?v=HypJY1XWkWY).
The gait of baboons, viz. the cross-walk, is the most stable of all gaits, because it
- spreads the weight over left and right sides, and
- maintains balance by keeping at least two feet on the ground throughout the cycle.
The main disadvantage of the cross-walk is that the hind foot risks colliding with the corresponding fore foot, unless placed to its side. This means a slight sideways swing in the gait, detracting from forward propulsion.
In summary so far, the cross-walk is stable but somewhat inefficient. It is not a particularly smooth gait for any fairly long-legged mammal.
Now, returning from primates to ungulates:
Hippopotamidae are technically hoofed mammals, despite the fact that their feet are only slightly unguligrade.
Hippopotamus cross-walks (https://www.youtube.com/watch?v=jqIjyqtSSzo and https://www.youtube.com/watch?v=OLrzqwb8M6o and https://www.youtube.com/watch?v=A8oZ8WRJ3ZM and https://www.youtube.com/watch?v=5jgES8ccMPI).
Furthermore, this is more fully a cross-walk than in baboons, in which the fore foot swings forward noticeably before the opposite hind foot does.
In Hippopotamus, there is no risk of interference between hind and fore feet, because the legs are short relative to the long body.
The pygmy hippo (Hexaprotodon) walks surprisingly differently from its large relative. The synchrony between fore and diagonally opposite hind is lost, so that the stride pattern resembles 'one foot at a time' (thttps://www.youtube.com/watch?v=uYTFo0AGqDw and https://www.alamy.com/stock-photo-pygmy-hippopotamus-choeropsis-liberiensis-adult-walking-on-grass-111494278.html and https://www.alamy.com/stock-photo-pygmy-hippopotamus-choeropsis-liberiensis-hexaprotodon-liberiensis-17801717.html and scroll in https://abc7news.com/baby-pygmy-hippo-melbourne-zoo-cute-animals/795280/).
The difference within Hippopotamidae, between species differing ten-fold in body mass, seems to confirm that, in ungulates, the cross-walk is associated with a premium on maintaining stability.
For the rest of this Post, I will refer to the gait exemplified by the pygmy hippo as a 'semi cross-walk'. This is shared with e.g the horse (Equus caballus, https://www.youtube.com/watch?v=t4zdTn02PWQ).
FROM ONE EXTREME TO THE OTHER: HIPPOPOTAMUS TO GIRAFFE
From the least unguligrade of ungulates, let us now turn to some of the most unguligrade, viz. Giraffa.
Part of the reason for the evolution of hooves is increased locomotory efficiency and speed, at some expense of stability.
This is taken to extremes in Giraffa, in which the length of the legs means increased efficiency in walking, without particular regard to stability. Balance is maintained partly by means of the cantilevering effect of the long, massive neck.
The result is an ambling gait, in which the legs are swung not in diagonal pairs but instead in like-sided pairs (https://www.youtube.com/watch?v=Vh2yveXTKaU and https://www.youtube.com/watch?v=DX-PbjeeB6o and https://www.youtube.com/watch?v=xMfn_7I76kI and https://www.youtube.com/watch?v=2lxa9LJTz9I).
In the amble, the reduction of spread of the weight between left and right is compensated partly by the tendency for three feet (as opposed to only two in the full cross-walk) to be on the ground for part of the cycle.
To summarise so far:
Ungulates are like 'tetrapods on stilts', to varying degrees. No ungulate with legs proportionately longer than those of Hippopotamus uses a full cross-walk. This is presumably because such a gait would trade off necessary efficiency for superfluous stability, diminishing the advantage of being unguligrade in the first place.
Those ungulates - beyond Hippoptamidae - emphasising stability tend, presumably, to be associated with
- unstable terrain,
- clutter of vegetation/rocks,
- the intermittent, furtive locomotion associated with a tactic of hiding from predators, and
- a tendency suddenly to 'freeze' when alarmed, often with one foot suspended mid-stride (https://www.alamy.com/curious-roe-deer-cervus-elaphus-buck-in-summer-at-sunset-watching-with-one-leg-lifted-in-the-air-roebuck-with-vivid-warm-colors-with-positive-senti-image242003830.html?imageid=F691EBBC-74FD-4C6D-B9E7-24F6805C62EA&p=788497&pn=1&searchId=70ac798c647adbbdaf10a03667d93407&searchtype=0 and https://www.istockphoto.com/photo/rare-meneliks-bushbuck-standing-in-the-forest-gm1145425223-308304724?phrase=bushbuck and https://www.alamy.com/female-bushbuck-tragelaphus-scriptus-looking-at-camera-one-leg-lifted-image62385488.html?imageid=89B00857-A21B-4F64-B081-C49DED4EDFC4&p=191737&pn=1&searchId=70ac798c647adbbdaf10a03667d93407&searchtype=0).
Those ungulates emphasising locomotory efficiency tend instead to be associated with
- firm, smooth ground,
- open vegetation, and
- cursoriality, with a tactic of fleeing from predators with speed and endurance.
The cross-walk and the amble constitute a continuum, in which the walking gaits represent gradations rather than a simple dichotomy. In the intermediate zone, where is the dividing line between the categories?
There are two ways to distinguish the semi cross-walk from the amble, as follows:
- criterion based on avoidance of collision of hind with fore hoof, and
- criterion based on lifting of hind hoof relative to landing of opposite fore hoof
CRITERION BASED ON AVOIDANCE OF COLLISION OF HIND WITH FORE HOOF
When the hind hoof swings forward, the fore hoof on the same side lifts either
- after the hind hoof touches the ground (semi cross-walk), or
- before it touches the ground (amble, see https://www.youtube.com/watch?v=ZwKdHJdCMgg).
This subtle distinction is significant, for the following reason. The former means the placement of the hind hoof behind the track of the fore hoof, thus limiting the length of the stride and, correspondingly, the efficiency of locomotion, whereas the latter allows the hind hoof to be placed in or in front of the track of the fore hoof - thus not limiting the length of the stride as the animal goes from slow walking to rapid walking.
Semi cross-walk:
Alces https://www.deviantart.com/nini1965/art/A-Young-Bull-Moose-Walking-in-a-Field-917220578
Alces https://www.shutterstock.com/image-photo/profile-bull-moose-walking-onto-dirt-116525839
Taurotragus https://www.pexels.com/photo/common-eland-walking-on-grass-field-13681228/
Taurotragus https://www.shutterstock.com/image-photo/male-eland-walking-field-cattle-egret-2103184676
Strepsiceros https://www.wallpaperflare.com/deer-walking-on-grass-kudu-male-stripes-elegant-wildlife-wallpaper-ultkf
Strepsiceros https://www.vecteezy.com/photo/900750-kudu-antelopeb)
Amble:
To illustrate this distinction even more clearly:
Please carefully follow the feet in these footages of walking in Camelus, which ambles:
https://www.shutterstock.com/video/clip-1067425-camel-walking---slow-motion
...and, in turn, please note the configuration in the following of a specialist in rocky terrain, which is the converse of Camelus in that it uses a relatively full cross-walk:
Oreotragus https://www.dreamstime.com/klipspringer-ewe-oreotragus-walking-rocks-image155290074
CRITERION BASED ON LIFTING OF HIND HOOF RELATIVE TO LANDING OF OPPOSITE FORE HOOF
Semi cross-walk:
The following show the semi cross-walk of Alces. Please note that, by the time that the fore is about to be placed, the hind has already been lifted, for long enough that the lower leg has reached the vertical.
Alces https://fineartamerica.com/featured/walking-bull-moose-randy-straka.html
Alces https://pixels.com/featured/bull-moose-crossing-river-jack-bell.html?product=wood-print
The following, correspondingly, show the semi cross-walk of the largest-bodied of all antelopes.
Taurotragus https://www.istockphoto.com/photo/young-eland-walking-on-the-skyline-gm670061476-122489693
Amble:
The following, of Alcelaphus, shows the difference between the semi cross-walk of tragelaphins (including Taurotragus) and the amble of alcelaphins (including Alcelaphus). The hind hoof is lifted only once the fore hoof has touched the ground.
The following shows that Camelus, although similar to Alces in the proportional length of the legs, is similar in walking gait to alcelaphins, and different from Alces.
https://www.gettyimages.com.au/detail/photo/side-view-of-camel-walking-royalty-free-image/1146381538
DISCUSSION
Hippopotamus cross-walks, while Giraffa ambles, despite both of these ungulates being megaherbivores.
This difference is unsurprising, given that
- in Giraffa, a cross-walk would produce excessive interference between fore and hind feet, and
- in Hippopotamus, the body would rapidly tip to the side if both legs on that side were simultaneously lifted.
Given that both Giraffa and Camelus amble, it is easy to assume that all relatively long-legged ungulates amble.
However, this is not so. Alces has legs proportionately longer than in any other cervid, yet it cross-walks, much like the pygmy hippopotamus.
The adaptive explanation is that Alces relies on locomoting rapidly and efficiently over fallen logs and through deep snow.
As Valerius Geist has pointed out, "when fleeing from enemies they can clear obstacles about...1 m...high without jumping, thanks to their large body and long legs. A wolf or bear on the trail of a moose, however, has to jump to get over such an obstacle...Smaller predators following the moose therefore become fatigued much sooner than the moose. On uneven ground a running moose can pass a horse easily".
The above quote refers to the trotting gait of Alces, which is basically a speeded-up version of the cross-walk, in which all four feet are simultaneously off the ground for part of the cycle. However, the efficiency applies also to cross-walking - with feet lifted high - through cluttered terrain, while foraging and commuting.
Another instructive comparison is between the pygmy hippo and Oreotragus, which is so extremely specialised for locomotion on rocks that it walks not only on its hooves but on the tips of its hooves (https://animals.sandiegozoo.org/animals/klipspringer and https://upload.wikimedia.org/wikipedia/commons/9/9f/Klipspringer_%28Oreotragus_oreotragus%29_feet.jpg).
Despite the pygmy hippo being hardly unguligrade and Oreotragus being 'hyperunguligrade', both semi cross-walk.
This is presumably because - for different reasons - both emphasise stability over efficiency of locomotion. Oreotragus risks stumbling and injuring itself on the rocks while the pygmy hippo risks slipping on mud and tripping on ground-level clutter in rainforest.
27 de septiembre de 2023
Dairy products in the context of human biology
@adriaan_grobler @ahabib @aimeebellsa @akshyop1029 @annikaml @beartracker @benjamin_walton @bluehillescape @botswanabugs @brhonda @bschwamb @buddyfede @cgbc @dalempijevic1 @dejong @dereksilberblatt @zarek @davidbygott @devbagdi @dmantack @doug263 @edison10 @emmastar123 @fabriciovilela @farrengdell @frostfox @gancw1 @gond @gori88lla @hlknight @hopeland @jacqueline_llerena @jeremygilmore @jessster78 @johnlenagan @juancruzado @julesdeboutte @kai_schablewski @karl_feng @koenbetjes @marceloamores @marina_gorbunova @marshall20 @matthewinabinett @maxkirsch @mbwildlife @mecopteron_bouillon @mgargiulo @melagiris_wildlife_kans @missoum73 @misumeta @muir @navaneethsinigeorge @nickolasmenez @noahfenwick @oumarouhamadou @paradoxornithidae @patriciocowpercoles @pauloc1985 @redwan21 @rkct @robert_taylor @sarinozi @skejo @standingquarter @shiwalee @thbecker @tonyrebelo @dinofelis @capracornelius @maxallen @oviscanadensis_connerties @tandala @michalsloviak @wildpokedex @yvettevanwijk1941 @karoopixie @wxwtx @wynand_uys @happyasacupcake @gigilaidler @marcelo_aranda @ludwig_muller @aguilita @nyoni-pete @calebcatto @simontonge @bobby23 @chewitt1 @nat_zouieva @hereinthewild @bluewhalenowhead @wjcrins @ldacosta @dianastuder @diegoeseolivera @andrespautasso @alexanderr @charles_stirton @troos @graham_g @mr_fab @margl @russellbarrett @kelnat @ladyrobyn @russellcumming @eremophila @botaneek @alan_dandie @scottwgavins @jayhorn @kelsey414 @torhek @chuditch @sea-kangaroo @george_seagull @jango1971 @douglasriverside @nwatinyoka @jwidness @jakob @rhinolophus @grahamarmstrong @wa_botanist @wa_zoologist @jessesaofia @leithallb @mikegrutherford @isaacclarey @chewitt97 @biohexx1 @saber_animal @jamesjarrett00 @graysquirrel @drshawntdash @grinnin @magdastlucia @pelagicgraf @henrydelange @christiaan_viljoen @jandutoit @felix_riegel @adamwelz @richard_johnstone @ralf_buerglin @moxcalvitiumtorgos @lmuller
Dear readers,
Please tune in to
https://www.youtube.com/watch?v=dTyYzZa2aXE&t=2475s
With kind regards from Antoni Milewski
24 de septiembre de 2023
A comparison of postures and gaits between two 'elands', the moose (Alces alces) and the common eland (Taurotragus oryx)
Also please see https://www.inaturalist.org/journal/milewski/69307-a-new-observation-on-maternal-defensive-behaviour-in-the-moose-alces-alces#
When the Dutch landed in South Africa in the late seventeenth century, they found the strange bovid, Taurotragus oryx, to be so similar to the familiar cervid, Alces alces, that they used the same name.
'Eland' is the Dutch word for Alces alces alces (https://www.inaturalist.org/observations?taxon_id=852458), which was originally indigenous to the Netherlands.
This adoption of a misnomer - which has persisted for nearly four centuries - is understandable, because both species
- are the largest-bodied members of their respective categories of ruminants, namely deer vs antelopes,
- habitually trot, rather than cantering/galloping, when pursued (https://www.google.com.au/search?q=Eland+bulls+fighting&sca_esv=568362559&sxsrf=AM9HkKlgG-AUfAcw_VbOYYgCRYuv81AY2w%3A1695692872768&source=hp&ei=SDgSZfTzLLXMseMPp9y1mAk&iflsig=AO6bgOgAAAAAZRJGWCnf_rbtFmhUhTBCL4oux5QgVTD9&ved=0ahUKEwj0t8-alMeBAxU1ZmwGHSduDZMQ4dUDCAs&uact=5&oq=Eland+bulls+fighting&gs_lp=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&sclient=gws-wiz#fpstate=ive&vld=cid:11586598,vid:OWcItn5k7KI,st:0),
- possess noticeably high withers (https://www.dictionary.com/browse/withers), and
- possess dewlaps (https://www.merriam-webster.com/dictionary/dewlap) in both sexes, which are more noticeable than the short nuchal mane present in both species.
In this Post, I compare A. alces with T. oryx with respect to postures and gaits, in light of the profound differences in their habitats and niches.
LYING
Both species rest in sternal recumbency (https://bestofthetetons.com/2014/11/18/resting-moose-a-collection-of-less-seen-lifestyle-images/ and https://www.alamy.com/stock-photo/eland-lying-down.html?sortBy=relevant).
KNEELING
A major difference is that A. alces kneels readily at all ages (https://www.azotelibrary.com/en/image/a-moose-%28alces-alces%29-kneels-to-eat-grass-in-a-meadow-in-s%C3%B6dermanland/191539), whereas T. oryx seems never to kneel (apart from transitorily when lying down in sternal recumbency, or arising from such lying, https://www.bestofthetetons.com/wp-content/uploads/2014/11/RestingMoose_GettingUpSequence1400px.jpg and https://www.shutterstock.com/image-photo/eland-antelope-rising-grass-savannah-green-2247874629).
When drinking, T. oryx sometimes spreads its forelegs to some degree, in partial emulation of Giraffa (https://www.alamy.com/giraffe-and-elands-at-a-waterhole-area-etosha-national-park-namibia-africa-image415771067.html?imageid=16AC8853-6C1A-4753-BFF4-3ABEAFFEE8E7&p=1364503&pn=1&searchId=c841ad5a0499198295bbf8dbec6d6cc6&searchtype=0 and https://africageographic.com/stories/eland/ and https://www.pinterest.com.au/pin/vertical-photo-of-huge-eland-antelopetaurotragus-oryx-standing-under-angolan-giraffe-drinking-from-waterhole-animals--664492120013532545/ and https://www.sciencephoto.com/media/389750/view/eland-antelope-drinking and https://fineartamerica.com/featured/eland-antelope-drinking-tony-camachoscience-photo-library.html?product=wood-print and https://www.alamy.com/stock-photo-eland-drinking-at-waterhole-etosha-namibia-19949416.html and https://www.gettyimages.ae/detail/photo/common-eland-drinking-at-chudop-waterhole-etosha-royalty-free-image/1032889546).
I have yet to see a similar posture in A. alces - which instead kneels in such situations.
When sparring or fighting in masculine rivalry, neither species routinely kneels (https://www.shutterstock.com/image-photo/common-eland-taurotragus-oryx-male-fight-2255105889). In the case of T. oryx, I have yet to see evidence of any kneeling at all.
There are many photos on the Web of A. alces in kneeling posture (please see examples at the end of this Post).
JUMPING
Alces alces can jump 2 m high, whereas T. oryx can jump 3 m high (https://naloolo.wordpress.com/2018/03/11/jumped-over-by-an-eland/).
The former species is a capable jumper, in line with other cervids. However, the latter is a remarkable jumper indeed. This is the converse of what might be predicted based on the length of the legs.
STOTTING
Alces alces is not known to stot. However, it is possible that, when it trots with particularly high steps (https://www.istockphoto.com/photo/young-bull-moose-running-across-stubble-field-gm491959369-40066416?phrase=elk+running+snow), this may be a demonstration of fitness, analogous to the proud-trotting of certain other ruminants.
Also deserving further scrutiny is the juvenile 'play-trotting', while wading, seen in https://www.youtube.com/watch?v=lVPfRQjDPBE.
By contrast, T. oryx has often been photographed 'stotting', in a way different from most other bovids. Instead of bouncing stiff-legged, individuals leap randomly, and seemingly pointlessly, while galloping in alarm in a group (https://twitter.com/Min_TourismKE/status/720195243241578496/photo/2 and https://www.zooniverse.org/projects/zooniverse/snapshot-serengeti/talk/1485/912470 and https://www.alamy.com/stock-photo-africa-kenya-masai-mara-motion-blur-of-eland-jumping-through-grass-32822773.html?imageid=B09244FD-293E-4CD1-B166-556A9E4CB550&p=95453&pn=1&searchId=6101ba2c62ae717283a6f3f1f002323c&searchtype=0 and https://www.alamy.com/stock-photo-eland-taurotragus-oryx-herd-running-laikpia-kenya-125584865.html?imageid=2DF7F368-4CD7-498D-97F8-AF1C2B837801&p=361664&pn=1&searchId=010f32aaa73c04f1f11960177dc59d66&searchtype=0). This may function similarly to stotting, in demonstrating individual fitness to potential predators.
BIPEDALITY
Alces alces sometimes stands bipedally, both to forage (https://www.reddit.com/media?url=https%3A%2F%2Fi.redd.it%2Feot6wzys7i981.jpg) and to quarrel (https://www.gettyimages.ca/detail/video/cow-moose-standing-up-on-their-hind-legs-and-fighting-in-stock-footage/460383460 and scroll in https://www.canadiannaturephotographer.com/Joe_Desjardins.html).
By contrast, T. oryx - as far as I know - never uses any bipedal posture except transitorily (for a split-second) by males in copulation (https://www.dreamstime.com/stock-photo-common-elands-mating-pair-taurotragus-oryx-amakhala-game-reserve-eastern-cape-south-africa-image51205440). Even in copulation, males support their weight on the females (https://www.agefotostock.com/age/en/details-photo/a-pair-of-common-elands-taurotragus-oryx-mating-in-the-amakhala-game-reserve-eastern-cape-south-africa/ESY-026334176).
Taurotragus oryx compensates for its inability to stand bipedally, by breaking branches with its horns (https://www.youtube.com/watch?app=desktop&v=tqe_qvUX43k). Alces alces also breaks woody stems while foraging, but does so by
- reaching up with its mouth and then pulling downward, or
- walking against an upright stem to force it down by means of the chest (https://winterberrywildlife.ouroneacrefarm.com/2019/08/09/moose-feeding-sign-with-video/).
FORAGING NEAR GROUND LEVEL WITHOUT KNEELING
Both A. alces and T. oryx are capable of foraging, without kneeling, on terrestrial plants lower than 20 cm above ground level. This is because the former combines a short neck with a long muzzle, whereas the latter combines a relatively long neck with a relatively short muzzle.
However, foraging in this way is easier for T. oryx than for A. alces, the former grazing as a staple part of its foraging (short green grass during the rainy season), whereas the latter seldom grazes. The neck of A. alces is so proportionately short that the length of the muzzle does not quite compensate.
Thus the shoulders and elbows are more flexed in an awkward posture in the case of A. alces, with the humerus approaching the horizontal (https://www.usgs.gov/media/images/moose-alces-alces-19 and https://unsplash.com/photos/tLUKrYFh4-w and https://pixels.com/featured/bull-moose-in-velvet-grazing-edie-ann-mendenhall.html and https://www.123rf.com/photo_6921276_bull-moose-grazing.html and https://www.agefotostock.com/age/en/details-photo/alaska-moose-grazing-in-tundra-male-moose-in-green-tundra-grazing-alaska/MEV-12905729).
By contrast, T. oryx appears more at ease when grazing.
To reach ground level itself with the mouth, the two species differ categorically. Alces alces is incapable of doing so without kneeling, whereas T. oryx does so by flexing the shoulders and elbows slightly (https://www.alamy.com/cape-eland-grazing-at-de-hoop-national-reserve-cape-overberg-south-image9879753.html?imageid=43081444-5267-444D-BC18-39F285FC4BCE&p=6945&pn=1&searchId=bebe53939638886546a1f3e44729a7e9&searchtype=0 and https://www.alamy.com/eland-taurotragus-oryx-de-hoop-nature-reserve-western-cape-south-africa-image399153412.html?imageid=B11E5FBA-723B-4A35-8CD5-F15BD837EF7F&p=12455&pn=2&searchId=5cd2bf43ed0e0cf1d243f5a9906dcb64&searchtype=0).
WALKING
Please also see https://www.inaturalist.org/journal/milewski/85161-variation-in-walking-gaits-in-ungulates-why-some-hoofed-mammals-cross-walk-whereas-others-amble#.
Please see https://www.youtube.com/watch?v=t4zdTn02PWQ
Alces alces and T. oryx walk with identical gaits. This is a semi cross-walk, not an amble.
Semi cross-walking is typical of ungulates dependent on cover, whereas ambling is typical of gregarious ungulates adapted to open environments. Alces alces is more cover-dependent than T. oryx.
Alces alces is the only long-legged ungulate that semi cross-walks. For its part, T. oryx is possibly the only 'plains game' ungulate that semi cross-walks.
Alces alces fully cross-walks when walking backwards (https://www.youtube.com/watch?v=Z5eY7kVsLQA), as does the horse (Equus caballus, https://www.deviantart.com/nexu4/art/white-horse-walking-backwards-392656340 and https://kenziedysli.com/walking-backwards/).
The following show the semi cross-walk of A. alces. Please note that, by the time that the fore is about to be placed, the hind has already been lifted, for long enough that the lower leg has reached the vertical.
https://a57.foxnews.com/global.fncstatic.com/static/managed/img/fn2/video/876/493/edge_moose_052014.jpg?ve=1&tl=1
https://www.istockphoto.com/photo/bull-moose-gm1055977806-282201912
https://fineartamerica.com/featured/walking-bull-moose-randy-straka.html
https://www.alamy.com/bull-moose-denali-national-park-preserve-alaska-united-states-of-america-a-unique-optimised-version-of-an-image-by-nps-ranger-jw-frank-credit-npsjacob-w-frank-image454466690.html?imageid=DC229BEB-798B-4807-AFC7-245D832C911F&p=1837101&pn=1&searchId=acbc6be48e9684687a1dabcb59018a60&searchtype=0
https://pixels.com/featured/bull-moose-crossing-river-jack-bell.html?product=wood-print
The following, correspondingly, show the semi cross-walk of T. oryx.
https://www.kimballstock.com/popuppreview.asp?db=a&image=AFW+36+MH0004+01&itemw=4&itemf=0001&itemstep=1&itemx=1
https://www.istockphoto.com/photo/young-eland-walking-on-the-skyline-gm670061476-122489693
https://www.alamy.com/common-or-southern-eland-taurotragus-oryx-de-hoop-nature-reserve-western-cape-south-africa-image555774369.html?imageid=B8DBE331-4F0A-4C2E-9AA5-68B247944D26&p=824482&pn=1&searchId=bebe53939638886546a1f3e44729a7e9&searchtype=0
The following, of Alcelaphus caama, shows the difference between the semi cross-walk of tragelaphins (including T. oryx) and the semi amble of alcelaphins (including hartebeests). The hind hoof is lifted only once the fore hoof has touched the ground.
The following shows that Camelus dromedarius, although similar to A. alces in the proportional length of the legs, is similar in walking gait to alcelaphins, and different from A. alces.
https://www.gettyimages.com.au/detail/photo/side-view-of-camel-walking-royalty-free-image/1146381538
TROTTING
Both species trot, as their preferred gait in running (https://www.youtube.com/watch?v=yxTsf51vqmE and https://www.youtube.com/watch?v=e-PA5qsOjBg).
Alces alces can trot with a high-stepping style, allowing it
- to clear obstacles such as fallen logs, without jumping, and
- to run through deep snow (https://www.youtube.com/watch?v=6GEhM2Byk7w).
Because its legs are so long, its speed while trotting corresponds to the cantering gait of other ruminants of similar body mass.
For its part, T. oryx is remarkable in that it trots even when in immediate danger from predators (https://www.imdb.com/title/tt8349694/ and https://thegreatestmaasaimara.com/?competition_data=cheetah-hunting-eland).
CANTERING
Please see https://www.youtube.com/watch?v=AoLg6aDqwUI
I have yet to see evidence that either A. alces and T. oryx ever canter.
GALLOPING
Please see https://www.youtube.com/watch?v=RV9P0w8vZi8 and
Both species are capable of galloping for limited distances.
Alces alces:
!https://www.youtube.com/watch?app=desktop&v=XlcypwnGcjQ
https://www.facebook.com/fox13seattle/videos/snowboarders-film-moose-running-alongside-them-down-mountain/10156033272534199/?locale=ms_MY
https://www.alamy.com/stock-photo-galloping-moose-on-the-run-39492457.html?imageid=5350CBC7-C4B1-4B9A-9B64-6D290EE4B904&p=34828&pn=1&searchId=9980e653e8ba1e2c918d82ab21cc4bd3&searchtype=0
https://www.alamy.com/stock-photo-galloping-moose-on-the-run-39492473.html?imageid=33DB1C68-DD8A-4C00-AD3B-DC32CDCC8420&p=34828&pn=1&searchId=9980e653e8ba1e2c918d82ab21cc4bd3&searchtype=0
https://www.alamy.com/eurasian-elk-alces-alces-alces-galloping-jaemtland-or-jamtland-sweden-image61916611.html?imageid=3BC9868E-A8B6-4863-99A7-6C3CC44A4B4A&p=75026&pn=1&searchId=9980e653e8ba1e2c918d82ab21cc4bd3&searchtype=0
Taurotragus oryx:
https://www.alamy.com/stock-photo-cape-eland-running-through-the-golden-grasses-of-the-open-serengeti-23833726.html?imageid=ED4E0569-531B-4524-BA79-6BD1B4DFE2A1&p=17446&pn=1&searchId=010f32aaa73c04f1f11960177dc59d66&searchtype=0
https://www.alamy.com/stock-photo-cape-eland-running-through-the-golden-grasses-of-the-open-serengeti-23832589.html?imageid=17B542F1-E9D2-4E86-826E-EF7E8C5BB3F9&p=17446&pn=1&searchId=010f32aaa73c04f1f11960177dc59d66&searchtype=0
https://www.alamy.com/eland-running-taurotragus-oryx-masai-mara-kenya-image181597557.html?imageid=B8F85DBD-7D48-4E42-9140-A35A91064D77&p=738418&pn=1&searchId=010f32aaa73c04f1f11960177dc59d66&searchtype=0
https://www.alamy.com/eland-taurotragus-oryx-masai-mara-kenya-image181635085.html?imageid=BA59C0DA-E616-4513-896B-D62F229A744A&p=738418&pn=1&searchId=010f32aaa73c04f1f11960177dc59d66&searchtype=0
https://www.alamy.com/stock-photo-eland-taurotragus-oryx-pair-running-through-spring-flowers-west-coast-125584310.html?imageid=86EB619E-ADDE-42BF-A3F5-11AD3FF7BAD5&p=361664&pn=1&searchId=010f32aaa73c04f1f11960177dc59d66&searchtype=0
https://www.alamy.com/stock-photo-eland-taurotragus-oryx-pair-running-through-spring-flowers-west-coast-125584310.html?imageid=86EB619E-ADDE-42BF-A3F5-11AD3FF7BAD5&p=361664&pn=1&searchId=010f32aaa73c04f1f11960177dc59d66&searchtype=
SWIMMING
Alces alces is one of the most proficient swimmers among ruminants (https://northernontario.ctvnews.ca/northern-ont-logging-crew-rescues-moose-that-fell-through-the-ice-1.5774814). It swims extremely rapidly, with endurance, and it can dive so deep while foraging that it disappears completely below the surface.
This is consistent with its foraging niche, which combines browsing on the foliage of trees and shrubs with holding its breath and submerging its head for aquatic algae and herbaceous plants.
By contrast, T. oryx has - as far as I know - never been recorded either swimming or foraging in wetlands. It is probably capable of swimming, given that its tragelaphin relatives are known to be capable swimmers. However, T. oryx
- is generally associated with dry climates,
- tends to avoid the dense vegetation near rivers, and
- is not known to take refuge in water when pursued by predators.
DISCUSSION
Estes (1991, page 190) states:
"Elands only gallop when badly frightened (or playing) and if pursued quickly tire...a trot...is the eland's fastest gait under usual conditions; it can trot at a rate of 35 kph for several kilometres, or much further at a slower rate...Is it the eland's bulk that makes it slow, or is it simply a tragelaphine trait the eland has been unable to change in adapting to open habitats? Cows are not particularly bulky and certainly calves not at all, yet both are slower than other plains antelopes. The fact that elands, like their closest relation, the kudu, are incredible high jumpers is also against the bulk argument. Fleeing elands often display their prowess...by jumping effortlessly right over a neighbor, and youngsters can sail over a 3 m fence from a standing jump".
ILLUSTRATIONS OF ALCES ALCES IN KNEELING POSTURES
https://gf.nd.gov/magazine/2020/feb/kneeling-moose
https://www.flickr.com/photos/annkelliott/18675993910
https://stock.adobe.com/images/kneeling-moose/210074588
https://www.inaturalist.org/observations/46888551
http://www.silencelikethunder.com/kneeling-moose.html
https://www.reddit.com/r/alaska/comments/hhwh1k/moose_kneeling_to_eat_in_my_side_yard/
https://www.istockphoto.com/photo/moose-kneeling-to-eat-green-grass-gm859156154-142020203
https://www.youtube.com/watch?v=e4-39sCnsTs
https://www.youtube.com/watch?v=M26ug8MGYlY
23 de septiembre de 2023
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:
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).
21 de septiembre de 2023
The remarkable - and perhaps unnatural - success of the moose (Alces alces shirasi) in Colorado, as evidenced by observations in iNaturalist
@muir @matthewinabinett @davidbygott @aguilita
The moose (Alces alces) was virtually absent from Colorado (https://en.wikipedia.org/wiki/Colorado), at the time in the late 1800's when there was general depletion of large mammals in North America.
The appropriate subspecies, reintroduced/introduced to Colorado about 45 years ago, has become common here, at the southern extreme of the distribution of the species in the world.
Please see https://coloradooutdoorsmag.com/2021/03/03/colorado-moose-reintroduction/ and https://k99.com/colorado-has-one-of-the-fastest-growing-moose-populations-in-u-s/ and https://cpw.state.co.us/documents/wildlifespecies/mammals/moosereintroductionfactsheet.pdf and https://coloradoencyclopedia.org/article/moose#:~:text=In%20the%201970s%2C%20there%20were,to%20other%20parts%20of%20Colorado. and https://cpw.state.co.us/learn/Pages/MooseReintroductionProgram.aspx and https://www.denverpost.com/2017/06/27/colorado-moose-coexisting-people/ and http://peaktocreekfilms.com/comoosefilm and https://www.aspendailynews.com/moose-flourishing-in-colorado/article_56681247-d99a-5e80-bfc1-effeed27b741.html and https://www.steamboatpilot.com/news/many-more-moose-local-population-has-increased-dramatically-in-20-years/ and https://art19.com/shows/colorado-outdoors/episodes/899ceb83-518c-466f-9c27-76207e1ca166 and https://www.coloradovirtuallibrary.org/resource-sharing/state-pubs-blog/viewing-moose-in-colorado/ and https://cpw.state.co.us/learn/Pages/LivingwithWildlifeMoose.aspx.
The population in Colorado is reported to have reached 3,000 in 2023. Hunting of this, the largest game animal in the state, is now routinely permitted.
What is particularly remarkable about this project is the degree to which it has been apparent to naturalists. The photos of the moose in Colorado, posted in iNaturalist, already exceed 3,000 (https://www.inaturalist.org/observations?page=27&place_id=34&taxon_id=522193).
This means that, in a sense, there is one photo for every individual of the moose in Colorado. How could both the moose and iNaturalist have been more successful?
However, this spectacular success is open to interpretation.
Is this a case of restoration of the natural occurrence of the moose, or an anthropogenic extension of the distribution of the species?
Comments from Readers would be welcome.
19 de septiembre de 2023
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,
- the antlers are paler than those of other cervids,
- the palmate surface of the antlers is far larger than in other cervids (https://www.cbc.ca/news/canada/north/possible-world-record-size-moose-shot-in-yukon-1.2075442), and
- the paleness of the antlers contrasts with the darkness of the rest of the figure.
This makes the antlers conspicuous, even at distance (https://www.inaturalist.org/observations/4612251).
The cornual flag in A. gigas
- is apparent mainly in autumn (https://www.josephfiler.com/photo/moose-alaska-2833/ and https://create.vista.com/unlimited/stock-photos/313125682/stock-photo-alaska-yukon-bull-moose-autumn-denali-national-park-alaska/), and
- hypothetically functions intraspecifically, aiding sexual attraction, male advertisement, and masculine rivalry.
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
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).
18 de septiembre de 2023
A new feature of adaptive colouration in ungulates: the fibular flag, part 2: Alces alces (Cervidae)
...continued from https://www.inaturalist.org/journal/milewski/70368-a-new-feature-of-adaptive-colouration-in-ungulates-the-fibular-flag-part-1-raphicerus-bovidae#
The moose (Alces alces, https://www.inaturalist.org/taxa/522193-Alces-alces) possesses a fibular flag (https://www.gettyimages.com.au/detail/photo/bull-moose-moving-through-northern-tundra-calling-royalty-free-image/657485842).
In this large-bodied cervid, the fibular flag covers the inner, and often also the outer, surfaces of the hindleg above the hock.
https://www.inaturalist.org/observations/107522426
The fibular flag of the moose is individually and seasonally variable, and also depends on illumination.
In the summer pelage, the fibular flag is poorly-developed (https://www.inaturalist.org/observations/179584604 and https://www.inaturalist.org/observations/170204579 and https://www.inaturalist.org/observations/79012704 and https://www.inaturalist.org/observations/31202401).
The following illustrate the fibular fag in Alces alces shirasi:
https://www.inaturalist.org/observations/22730337
https://www.inaturalist.org/observations/165808747
second photo in https://www.inaturalist.org/observations/183755724
https://www.inaturalist.org/observations/73121671
https://www.inaturalist.org/observations/4482611
https://www.inaturalist.org/observations/4308293
Fibular flag in Alces alces alces:
https://www.inaturalist.org/observations/35274716
https://www.inaturalist.org/observations/183855765
https://www.inaturalist.org/observations/183819576
https://www.inaturalist.org/observations/153934473
https://www.inaturalist.org/observations/46595843
https://www.inaturalist.org/observations/2922305
In nominate A. a. alces, the pale feature in question can be so expansive that the term 'fibular flag' no longer applies (https://www.inaturalist.org/observations/112176729).
ADDITIONAL ILLUSTRATIONS OF FIBULAR FLAG IN ALCES ALCES
https://www.inaturalist.org/observations/116777704
https://www.inaturalist.org/observations/115702446
https://www.inaturalist.org/observations/115325363
https://www.inaturalist.org/observations/115314501
https://www.inaturalist.org/observations/114790758
https://www.inaturalist.org/observations/112619055
https://www.inaturalist.org/observations/135414451
https://www.inaturalist.org/observations/115470987
https://www.inaturalist.org/observations/125843310
https://www.inaturalist.org/observations/121343112
https://www.inaturalist.org/observations/120257251
https://www.inaturalist.org/observations/129646111
https://www.inaturalist.org/observations/119626107
https://www.inaturalist.org/observations/119092478
https://www.inaturalist.org/observations/116521066
https://www.inaturalist.org/observations/134851345
https://www.inaturalist.org/observations/116789745
https://www.alamy.com/stock-photo-moose-from-behind-142718462.html
https://www.inaturalist.org/observations/131879614
https://www.inaturalist.org/observations/126552983
https://www.inaturalist.org/observations/125993345
Why A. alces is unusual, in possessing a fibular flag, is worthy of further investigation.
14 de septiembre de 2023
The hyperfecal-hypofecal continuum in consumers of plant matter
(writing in progress)
Faeces exist, almost as surely as eating exists.
The basic principles behind the production of faeces are of costs/benefits, and diminishing returns.
Various components of food have various digestibilities. The least digestible components are - depending on the species of consumer and its particular digestive system - discarded, as the biological equivalent of rubbish.
This occurs despite
- the investment of time and energy made in acquiring the food, and
- the risks taken as part of this foraging.
It would be naive to expect members of the 'food-chain' to be thorough processors, simply converting all of the matter and energy they consume.
However, what are remarkable are
- the degree to which various animals differ in the thoroughness of their digestive process,
- the quantity of faeces produced relative to food consumed, and
- the finding that it is not necessarily the most fibrous diets that produce the most faeces.
Some animals 'overproduce' faeces in the sense that they seem to extract little of what they eat, whereas others 'underproduce' faeces in the sense that they extract virtually all of what enters the digestive process. Most animals are intermediate.
It is the range in this continuum - which I dub the 'hyperfecal/hypofecal continuum' - that is greater than appreciated by many or most naturalists.
In this Post, I illustrate the hyperfecal/hypofecal continuum by examining its extremes, in the form of
- the giant panda (Ailuropoda melanoleuca, https://www.inaturalist.org/taxa/41659-Ailuropoda-melanoleuca), and
- fungus-culturing termites in genus Macrotermes (https://www.inaturalist.org/observations?place_id=any&taxon_id=346639&view=species).
Both the giant panda and Macrotermes forage on extremely fibrous matter, composed largely of cellulose (https://en.wikipedia.org/wiki/Cellulose) and lignin (https://en.wikipedia.org/wiki/Lignin).
However,
- the former acts as a 'fecal factory', whereas the latter recycles the fibre repeatedly within the system, until virtually nothing emerges; and
- the former seems to defecate for a living, whereas the latter - at least at the scale of the whole colony in this eusocial insect - hardly produces anything that can be called faeces.
Indeed, the digestive process of Macrotermes is such that it treats the faeces of various herbivores as part of the diet.
Crucial for understanding the hyperfecal/hypofecal continuum are
- the role of microbes, particularly fungi (https://en.wikipedia.org/wiki/Fungus#:~:text=Fungi%20include%20symbionts%20of%20plants,and%20exchange%20in%20the%20environment.), and particularly aerobic fungi (https://en.wikipedia.org/wiki/Termitomyces), and
- the repeated reingestion of food, slowing incremental breakdown of every particle of fibre.
In the giant panda, the gut is short and simple. There is minimal development of gut-chambers in which food is delayed for breakdown by bacteria and other microbes.
The result is that
- virtually all of the fibre emerges as faeces, and
- even the digestible proteins, such as chlorophyll, are only partly digested (https://www.pdxwildlife.com/does-panda-poop-stink/).
In other words, the hyperfecality of the giant panda is such that even the greenness of the plant matter consumed seems not to be converted to brown.
(writing in progress)
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