Archivos de diario de septiembre 2023

01 de septiembre de 2023

Surprisingly, the tiger (Panthera tigris) exceeds the lion (Panthera leo) in expressing bipedality

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The lion (Panthera leo) and the tiger (Panthera tigris)

Therefore, one would not expect these species to differ in their ability to adopt bipedal postures.

Yet there does seem to be a difference. The lion has not been observed to adopt bipedal postures to the extent and degree observed in the tiger.

The photographic evidence falls into three categories, namely

  • circus acts,
  • intraspecific antagonism, and
  • territorial marking.


Please see

I have yet to see a similar photo for the lion.


Both in play and in combat, the lion and the tiger rear up on their hindlegs to some degree.

However, the lion differs considerably from the tiger, as evident from the many photos (and a few video clips) shown at the end of this Post.

In combat/sparring, the tiger adopts a ritualised transitory posture, in which the animal stands/locomotes briefly on its hindlegs. At the same time, it spreads its forelegs - mirrored by its antagonist - in a way yet to be photographed/filmed in the lion.


The tiger often stands bipedally at the base of trees, in order to

  • rub its jowls on the bole, and/or
  • make conspicuous scratch-marks on the bark:

This is shown in the following:

I have yet to find any photo of the lion adopting a similar posture, in this context.

The closest are and and and


It would be particularly surprising for the tiger to exceed the lion in bipedal ability, given that it is the more massive of the two species ( and

Perhaps the difference can be explained partly by the fact that the lion typically inhabits open vegetation, whereas the tiger typically inhabits wooded vegetation.

These findings should raise a search-image, among naturalists, for bipedal modes in

The leopard (Panthera pardus) has repeatedly been photographed sitting bolt-upright in vigilance ( and However, this is different from standing.

Bipedal standing during marking on trees is the least important of the three lines of evidence considered here. This is because the animal does not free-stand, but instead uses the bole to support itself with its forepaws.

I offer the hypothesis that it is the lion, rather than the tiger, that is aberrant, among 'big cats', in its (lack of) expression of bipedality.

However, part of the explanation may lie in the fact that the tiger is significantly more brainy than the lion (


Scroll in


Publicado el septiembre 1, 2023 09:40 MAÑANA por milewski milewski | 8 comentarios | Deja un comentario

04 de septiembre de 2023

A comparison of the plains viscacha (Lagostomus maximus) and the black-tailed prairie dog (Cynomys ludovicianus)

(writing in progress)

Two rodents invite comparison, viz.

The former is a hystricomorph ( belonging to the Chinchillidae (, whereas the latter is a sciuromorph ( belonging to the Sciuridae (

The two species are comparable because both are

  • the largest rodents in their habitats (which are mainly mesic and treeless in both cases),
  • herbivorous (with green grass as a staple), to the degree of being regarded as unwelcome competitors for domestic livestock,
  • burrowing (mainly for the excavation of permanent living quarters)
  • colonial (with several family groups sharing a single system of burrows),
  • sexually dimorphic (with males more massive than females),
  • precocial (with large, well-developed newborns), and
  • unusually vocal for rodents (with various calls used socially and in reaction to predators),

However, the plains viscacha is the more specialised species in its role as a herbivore, and the more aberrant w.r.t. rodents in general.

This is because the plains viscacha

  • has about five-fold the body mass of the black-tailed prairie dog, as well as being the more sexually dimorphic of the two,
  • has a diet more strictly herbivorous (and graminivorous) than that of the black-tailed prairie dog,
  • forms and maintains lawns,
  • is caecotrophic (, as opposed to having hindgut fermentation without caecotrophy in the case of the black-tailed prairie dog, and
  • forages throughout the year, as opposed to spending the winter partly in torpor in the case of the black-tailed prairie dog.

with caecotrophic digestion

Nocturnal vs diurnal

Unlike the black-tailed prairie dog, the plains viscacha forages gregariously.

Publicado el septiembre 4, 2023 12:32 MAÑANA por milewski milewski | 11 comentarios | Deja un comentario

08 de septiembre de 2023

Is there a system of eating in which the systemically toxic excess of carbohydrate can be practically mitigated?

(writing in progress)

The main aim of this Post is to suggest a practical way of 'having one's cake and eating it too', in terms of healthy diets and systems of eating, in the human species (Homo sapiens).

The particular topic is the mitigation of the effects of carbohydrate (, which tends to be consumed in excessive quantity and with excessive frequency in the modern world.


In industrial economies today, so much carbohydrate is available to the human species that this substance has become, effectively, an environmental toxin.

This contrasts with the ancestral condition. Hunter-gatherers lived in an environment in which carbohydrate was seasonal and relatively scarce. The physiological nature of the human body is such that the former regime remains the healthier one.

Many chronic illnesses in modern populations can be ascribed to excess carbohydrate.

The mechanism is that concentrations of glucose in the blood tend to be excessive, with excessive frequency. This causes disruption of the normal functions of the pancreas (, mainly via the insulin ( secreted by this gland.

The results include, amongst others,

It seems safe to say that if all added sugar were eliminated from human diets, populations would be healthier.

Furthermore, it seems likely that most human individuals would be healthier on a diet lacking starchy foods - on the basis that starch is rapidly digested to glucose in the mouth and small intestine, causing metabolic stress similar to that resulting from consumption of sugar itself.

However, for most individuals in modern societies, it seems impractical - for many and diverse reasons - to eliminate sugar and starch entirely from the diet.

For example, the category of 'healthy vegetables' includes various tubers and fleshy fruits, which are starchy enough to boost glucose in the bloodstream, within minutes of consumption.

Examples of tubers include

Starchy examples of fleshy fruits are the various domestic species of Cucurbita ( and and

Furthermore, this undesirable boost would remain to some extent even if the foods mentioned above were eaten raw. This is because their glycemic index ( exceeds x.


It may be practicable to avoid added sugar, as well as sweet fleshy fruit-pulp and -juice, from one's diet.

However, for most individuals, it is impractical to avoid carbohydrates altogether. This would mean a ketogenic diet, which is physiologically possible for many or most individuals, but not sustainable given the social and economic realities of our lives.

So, how can one continue to consume, on a routine basis, some quantity of starchy food without ill effects?


I suggest that three crucial principles are that

  • the rate at which glucose enters the bloodstream depends largely on the dilution of carbohydrate in proteins, lipids, fibre, and water, in the stomach,
  • it is as important to reduce the frequency of 'insulin spikes' as it is to reduce the sizes of these 'spikes', and
  • mildly sweet food (e.g. wild berries) can safely be eaten provided that this is at most once per day, reducing the frequency of any 'insulin spikes' to one per day or less.

The best illustration of the first of the above principles is that peanut (Arachis hypogoea, and chickpea (Cicer arietinum, contain about a third starch, but are non-insulinogenic. The starch is safely 'smuggled' into then food by virtue of being thoroughly mixed with protein and, in the case of peanut, lipids.

Publicado el septiembre 8, 2023 08:55 TARDE por milewski milewski | 0 comentarios | Deja un comentario

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

Both the giant panda and Macrotermes forage on extremely fibrous matter, composed largely of cellulose ( and lignin (


  • 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

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

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)

Publicado el septiembre 14, 2023 11:25 TARDE por milewski milewski | 3 comentarios | Deja un comentario

18 de septiembre de 2023

A new feature of adaptive colouration in ungulates: the fibular flag, part 2: Alces alces (Cervidae)

...continued from

The moose (Alces alces, possesses a fibular flag (

In this large-bodied cervid, the fibular flag covers the inner, and often also the outer, surfaces of the hindleg above the hock.

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 ( and and and

The following illustrate the fibular fag in Alces alces shirasi:
second photo in

Fibular flag in Alces alces alces:

In nominate A. a. alces, the pale feature in question can be so expansive that the term 'fibular flag' no longer applies (


Why A. alces is unusual, in possessing a fibular flag, is worthy of further investigation.

Publicado el septiembre 18, 2023 10:08 MAÑANA por milewski milewski | 17 comentarios | Deja un comentario

19 de septiembre de 2023

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

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

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

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

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 ( and and and,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 (

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

Seasonal changes in colouration are limited. There is a single annual molt ( and and and in spring/early summer. The pelage, after being worn and weathered for a year, fades somewhat (

However, the pelage remains dark enough in winter to be conspicuous against snowy backgrounds, even at distance ( and

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

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

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


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 (

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

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

This makes the antlers conspicuous, even at distance (

The cornual flag in A. gigas

Cornual flag in Alces alces gigas:
scroll in

Cornual flag in Alces alces andersoni:

Possible cornual flag in Alces alces shirasi: and

Possible cornual flag in Alces alces americana:

Incipient cornual flag in Alces alces alces:


Please see

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 ( 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 (


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

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 (

The fetlocks and pasterns themselves are not whitish ( and and and and and, except in some individuals of the nominate A. a. alces (

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 ( and

To the degree that the pedal flag is valid in A. alces, it is linked to, and subsidiary to, the fibular flag ( In A. a. alces, the joint pattern can perhaps be called a pedofibular flag.


Please see

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

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

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

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

A. a. alces:

A. a. americana:

A. a. gigas:

A. a. andersoni:

A. a. shirasi:

In Alces alces, unlike another large cervid partly sympatric with it, the auricular semet does not disappear in mature males (see

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


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

However, there tends to be a pattern in which the broadly dark lower lip is offset by pale ventral to the gape. The clearest illustration is

The following are additional illustrations: and and and and scroll to second photo in and and and and and and

This pattern of colouration hypothetically accentuates the chewing movements ( This hypothetically aids vigilance during rumination, when two or more adult/adolescent individuals rest within sight of each other (

Buccal semet in Alces alces buturlini:

Buccal semet in Alces alces gigas:

Variation in this feature deserves further investigation. The pattern seems clearest in spring, when the worn, weathered pelage has faded but the dark on the lower lip has not faded ( The following shows the minimal expression of the buccal semet (, 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 ( and and

Publicado el septiembre 19, 2023 12:46 MAÑANA por milewski milewski | 30 comentarios | Deja un comentario

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 (, 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 and and and,to%20other%20parts%20of%20Colorado. and and and and and and and and

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 (

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.

Publicado el septiembre 21, 2023 01:59 MAÑANA por milewski milewski | 3 comentarios | Deja un comentario

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 (, 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 (, 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 (

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





no clear photos found




scroll to second photo in



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 (

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 | 15 comentarios | Deja un comentario

24 de septiembre de 2023

A comparison of postures and gaits between two 'elands', the moose (Alces alces) and the common eland (Taurotragus oryx)

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Also please see

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 (, which was originally indigenous to the Netherlands.

This adoption of a misnomer - which has persisted for nearly four centuries - is understandable, because 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.


Both species rest in sternal recumbency ( and


A major difference is that A. alces kneels readily at all ages (, whereas T. oryx seems never to kneel (apart from transitorily when lying down in sternal recumbency, or arising from such lying, and

When drinking, T. oryx sometimes spreads its forelegs to some degree, in partial emulation of Giraffa ( and and and and and and

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 ( 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).


Alces alces can jump 2 m high, whereas T. oryx can jump 3 m high (

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.

C R S Pitman ( recorded a case where a mature male individual of T. oryx (weighing perhaps >550 kg, and easily vaulted an enclosure 2.4 m high.


Alces alces is not known to stot. However, it is possible that, when it trots with particularly high steps (, 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

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 ( and and and This sometimes means leaping over the back of an adjacent individual. This behaviour may function similarly to stotting, in demonstrating individual fitness to potential predators.


Alces alces sometimes stands bipedally, both to forage ( and to quarrel ( and scroll in

By contrast, T. oryx - as far as I know - never uses any bipedal posture except transitorily (for a split-second) by males in copulation ( Even in copulation, males support their weight on the females (

Taurotragus oryx compensates for its inability to stand bipedally, as follows ( This species has often been observed to forage as high as 2.13 m, "frequently using their horns to break branches in order to get at the leaves" (J Posselt, African Wild Life magazine, June 1961).

Alces alces also breaks woody stems while foraging, but does so by


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 ( and and and and

By contrast, T. oryx appears more at ease when grazing ( and and and

To reach ground level itself with the mouth, the two species differ categorically.

Alces alces is incapable of doing so without kneeling (please see compendium of photos at the end of this Post).

By contrast, T. oryx does so by flexing the shoulders and elbows slightly, and leaving one foreleg at an angle ( and and and and and and


Please also see

Please see

Alces alces and T. oryx seem to 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 (, as does the horse (Equus caballus, and

The following show the normal semi cross-walk of A. alces. Please note that, by the time that the fore is about to be placed, the opposite hind has already been lifted, for long enough that the lower leg has reached the vertical.

The following, correspondingly, show the semi cross-walk of T. oryx.

The following ( nicely shows that, when T. oryx walks briskly, the left fore hoof touches the ground at the same instant that the right hind hoof loses touch with the ground. This is the normal configuration in walking in Syncerus caffer, as well as equids.

The following ( is intriguing in showing a full cross-walk in A. alces, in forward motion. I surmise that this extreme gait was resorted to during a brief crossing of unstable stony ground.

Walking gaits of other ungulates, for comparison:

The following, of Alcelaphus caama, shows the difference between the semi cross-walk of tragelaphins (including T. oryx) and the amble of alcelaphins (including hartebeests). The hind hoof is lifted only once the opposite 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. and and


Both species trot, as their preferred gait in running ( and and and and,Eadweard-Trottender_Eland%28Zeno_Fotografie%29.jpg and and and

Alces alces can trot with a high-stepping style, allowing it

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 ( and and and


Please see

I have yet to see evidence that either A. alces and T. oryx ever canter.


Please see and

Both species are capable of galloping for limited distances.

Alces alces:

Taurotragus oryx:


Alces alces is one of the most proficient swimmers among ruminants ( and and and and and

It can dive so deep while foraging that it disappears completely below the surface ( and

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 hardly been recorded swimming, or even foraging in wetlands. The following ( suggests that it is capable of swimming, which makes sense 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.


Estes (1991, page 190) states:
"Elands only gallop when badly frightened (or playing) and if pursued quickly tire...a 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 jumping effortlessly right over a neighbor, and youngsters can sail over a 3 m fence from a standing jump".


Publicado el septiembre 24, 2023 01:50 MAÑANA por milewski milewski | 42 comentarios | Deja un comentario

27 de septiembre de 2023

Dairy products in the context of human biology

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Publicado el septiembre 27, 2023 05:34 TARDE por milewski milewski | 3 comentarios | Deja un comentario