September 17, 2021

The Maasai donkey as a domensal animal

(writing in progress)

What do you call animal species living mainly among humans but not kept captive?

Commensal, naturally.

What do you call species which have been selectively bred by humans? Domestic, of course.

What do you call populations of domestic species which live wild? Feral, surely.

But what do you call breeds within domestic species which look like wild animals, are no longer selectively bred, and serve humans part-time and voluntarily?

There has been no word for this, so how about 'domensal' (domestic/commensal)?

The Maasai 'breed' of the donkey (Equus asinus), which inhabits East African pastoral areas from Somalia across Kenya to Tanzania, conforms to this description; hence the appeal, to naturalists, of a quasi-wild animal. And, given that no wild ancestor survives (at least in pure form), the Maasai donkey is as close as we can get today to a lost member of the original fauna.

Pastoralists such as the Maasai have allowed the donkey to revert to a semi-feral state, while retaining intimate cohabitation. And the Maasai donkey returns to its anthropogenic burdens seasonally, with minimal coercion (see

The Maasai donkey is not herded back to the corrals in the evenings, as are the domestic bost (Bos taurus/indicus), the domestic sheep (Ovis aries) and the domestic goat (Capra hircus) of the Maasai. Instead, it returns of its own accord, behaving in this sense like a commensal rather than a domestic animal.

Nor is the Maasai donkey exploited by the pastoralists for food (either flesh or milk). Its sole value is for transportation and then mainly on a seasonal basis, and it may or may not be individually 'owned' (branded) depending on which group of pastoralists is involved.

As far as I know, the pastoralists make little attempt to control the reproduction of the donkey; so there is negligible selective breeding despite considerable 'natural' selection.

Although it could be argued that the donkey remains permanently shaped by a previous history of selective breeding, what seems significant is that this population has remarkably consistent colouration, conforming to a wild pattern and lacking the irregular and asymmetrical features so obvious in the bost, sheep and goat kept by the same pastoralists. The Maasai donkey differs from its putative wild ancestors mainly in the reduced sizes of its body (adult average about 100 kg) and presumably brain. We do not know whether the wild-type colouration has been directly retained from the ancestral species, reverted to, or attained by recent hybridisation with the Somali wild ass (Equus africanus somaliensis).

Posted on September 17, 2021 04:51 by milewski milewski | 0 comments | Leave a comment

September 16, 2021

Back-of-ear barcode sorts the donkey from the zebras

Everyone knows that the donkey (Equus asinus) has large ear pinnae ( and and

Some may also know that the posterior surface of the ear pinna has a clear pattern in many individuals with otherwise relatively plain colouration ( and and and and and and and and and and and

But who knows how this pattern relates to the corresponding 'barcodes' seen in zebras?

Was the (extinct) wild ancestor of the donkey essentially just a relatively stripeless relative of zebras, in which the markings have been most persistent on the ears?

What the following comparisons show is that the pattern in the donkey is different from that in any species of zebra.

Although the patterns vary among the species and subspecies of zebras, the ear-tip, as seen from behind, is always whitish in zebras. By contrast, it is dark in the donkey (see and

Furthermore, whereas there is only one broad dark feature in the case of zebras, there tend to be two in the donkey, one of which includes the ear-tip and the other of which is close to the base of the ear pinna (see and and

The following compare Equus hartmannae with the donkey: and and vs and vs and

The following compare Equus grevyi with the donkey: and and and and and and vs and and

The following compare Equus quagga boehmi with the donkey: and vs and and

The following compare Equus quagga chapmani with the donkey: vs vs and and

Compare the donkey with the Somali wild ass (Equus africanus somaliensis): vs

Posted on September 16, 2021 01:22 by milewski milewski | 4 comments | Leave a comment

September 15, 2021

Earlashes: a major facial feature hiding in plain sight

What do you notice about this view of the face of the sambar deer (Rusa unicolor)?

Nothing in particular?

Try again. How about this view of the western grey kangaroo (Macropus fuliginosus)?

Still unsure what I'm referring to?

Surely this view of the dhole (Count alpinus) gives a hint too big to miss?

That's right, you are looking at earlashes, one of the most overlooked body parts in animals.

This is Wikipedia on earlashes:

(That's right. Nothing.)

Earlashes - the stiff hairs forming a partial curtain on the front of the ear pinna - are obvious in innumerable photos in iNaturalist and elsewhere on the web. However, as far as I know there has been no mention of them, as such, in the zoological literature. They have been 'hiding in plain sight' even though they are an important facial feature in many families of mammals.

One of the reasons why we humans tend to be oblivious to earlashes is that they happen to have been minimised in the evolution of primates.

In fact, even the cartilaginous ridge which bears the earlashes in other mammals and which remains (hairless) in humans has never received a name (see and and and and and and

One of the remarkable facts about earlashes is that they tend to be whitish, even in mammals with otherwise darkish ear pinnae.

For example, the earlashes are easy to see because they are particularly pale in Osphranter robustus ( and Osphranter antilopinus (

The following is a selection of illustrations of earlashes in various carnivores and ungulates.

Cuon alpinus

Lycaon pictus

Chrysocyon brachyurus

Felis lybica griselda

Leptailurus serval

Bubalus carabanensis

Syncerus nanus

Tragelaphus eurycerus

Strepsiceros strepsiceros

Rusa unicolor[gal]/1/[gal]/8/

Posted on September 15, 2021 10:57 by milewski milewski | 2 comments | Leave a comment

September 14, 2021

Beneficially bloodshot, from birds to buffaloes

As everyone knows, reddish hues in feathers or fur of birds and mammals are usually owing to pigments such as carotenoids (e.g. see,skin%20produce%20most%20feather%20colours.&text=Bright%20red%2C%20yellow%20and%20orange,generally%20get%20from%20eating%20plants.).

However, when bare skin changes from flesh-coloured to reddish, this is usually the colour of blood, not just pigments.

Skin can look blood-red, because the capillaries just beneath the skin dilate enough for oxygenated blood to show through. The red is the hue of hemoglobin (, which can be called a pigment but is the substance that transports oxygen in the blood.

And, in photogenic animals ranging from birds to large mammals, bare skin can be designed to become bloodshot. In some cases this is a social/sexual display, and in others the red skin acts as a radiator of excessive bodily heat in hot weather. This aid to thermoregulation can be particularly valuable in dry climates where water tends to be unaffordable for sweating.

The most familiar example is the comb of the domestic fowl (Gallus gallus). The skin and the capillary walls are translucent enough that the comb can look blood-red ( and and Although this may intensify in hot weather, its functions are mainly social/sexual in birds.

A similar but less obvious effect occurs in the ostrich (Struthio camelus): the neck of adult males becomes bloodshot in the breeding season ( and and Although this is for sexual display rather than thermoregulation, the important point is that the hue in the skin is that of blood, not that of the carotenoid pigments for which the feathers of flamingoes are so well-known (

In mammals, subtle effects of a similar kind have been overlooked. This is partly because they tend to be restricted to the ear pinnae, which are widely assumed to be large for hearing rather than the radiation of excessive heat. For example, who has previously noticed the following?

So, let us look at some large-eared mammals adapted to hot climates.

Some photos of hares (Lepus) suggest bloodshot ears in hot weather. In cool weather, the ear pinnae are translucent but flesh-coloured: However, in the following the hue has intensified to reddish: The following are not necessarily bloodshot but clearly show the blood vessels: and

Among ungulates, I have found the following examples. In each case I illustrate the ear first flesh-coloured, then bloodshot in what is presumably hot weather.

Odocoileus hemionus

Strepsiceros strepsiceros

Ammelaphus imberbis

Syncerus caffer

(for comparison, in the following there is a bleeding injury on the ear pinna:

Bos indicus

Posted on September 14, 2021 13:31 by milewski milewski | 4 comments | Leave a comment

September 13, 2021

Discovering an auricular semet in a kangaroo

Macropods ( vary greatly in the colouration of their ear pinnae, from plain ( and and to patterned ( and and

Kangaroos, defined as the five species of macropods with the largest bodies, are generally plain in colouration. However, their ear pinnae have ambivalent patterns.

In this Post, I try for the first time to classify these patterns in terms of the dichotomy between camouflage-colouration on one hand, and small-scale conspicuous colouration for social signalling on the other.

In all kangaroos, the earlashes (see are whitish, and noticeable at close quarters. However, at some distance the species vary between earlashes which could plausibly function as camouflage ( and those which, by virtue of dark emphasis, could plausibly function as an auricular semet (

Along similar lines, the back-of-ear of kangaroos, which is brought partly into view by turning the ears, is plain in certain species but differentiated into dark and pale in others ( and

Of the five species, only the western grey kangaroo (Macropus fuliginosus, combines relatively conspicuous earlashes with a relatively conspicuous back-of-ear. The pattern in this species is certainly conspicuous enough to qualify as an auricular semet: and and and and and

Presumably, the function of an auricular semet in the western grey kangaroo is to facilitate the monitoring of companions in this somewhat gregarious species. However, this raises a question for a future Post: why is it that the closely-related eastern grey kangaroo (Macropus giganteus) has a pattern probably too faint to qualify as an auricular semet?

Macropus giganteus

Macropus fuliginosus

Osphranter robustus

Osphranter antilopinus

Osphranter rufus

Posted on September 13, 2021 20:40 by milewski milewski | 1 comment | Leave a comment

Who will be first to scoop the eland eating an indigenous willow?

The Dutch were the first northern Europeans to explore southern Africa in the seventeenth century.

Immediately, at the site of what is now Cape Town, they met an antelope ( and which reminded them of the European Alces alces ( in its rangy build, trotting gait ( vs, dewlap, pale legs, and browsing habits.

They called this animal 'eland' because the Dutch name for the moose was, and still to this day is, 'eland'.

That is right: the common name for Taurotragus oryx, the largest species of antelope, is the same as the Dutch name for the largest species of deer.

Of course, everyone knows better than to read too much into a name coined as a historical accident. After all, the eland is restricted to Africa whereas the moose is restricted to the boreal North, and their ranges have always been thousands of kilometres apart, in categorically different climates.

However, there is one unexpected link between them, one of those caprices of Nature which can delight the biogeographical curiosity of any naturalist.

If there is a single genus of plants which is most significant for the moose, it is willows (Salix).

Willows are mainly rather nondescript-looking shrubs in a boreal biome characterised by its coniferous trees. However, it is the willows that the moose depends on ( because, like natural weeds, they are exceptionally nutritious, accessible and fast-growing, and seem to thrive on abuse by herbivores. In their innate generosity, willows can perhaps be thought of as the woody equivalent of lawns, flexible of stem and eager to be mown so that they can keep refreshing their growth during the brief Northern summer (

Indeed, it seems possible that, without these plants, the moose would not be able to afford its antlers - which, unlike the horns of the eland, are re-grown and discarded each year as if by analogy with the affluent foliage of the willows (

Given that Africa is a hemisphere, a continent and several floras apart from the home of the moose, who would have predicted that a species of willow would occur - an outlier but fully indigenous - in the habitat of the eland? And that it would occur on the very site where the Dutch first landed, and first met the eland?

Such is the case for the Cape willow (Salix mucronata), which grows widely but inconspicuously in South Africa (see map in

The Cape willow is probably not as nutritious as the boreal willows favoured by the moose. However, it was probably part of the original diet of the eland, which occurred throughout the distribution of this plant species.

To obtain a once-in-a-lifetime photo of the eland 'coming full circle' to its namesake, in eating the Cape willow, naturalists still have several places to visit with a specific search-image.

The most natural of these - still nearly the same as it was when the Dutch first established Cape Town more than three centuries ago - would be the Nyika Plateau of Malawi (, where the eland remains common in an original, wild population ( Here the Cape willow grows in a unique outlying population deep within the tropics (

There should also be several conservation areas, including privately-owned ones, in various parts of South Africa, particularly the provinces of Western Cape (e.g. and, Eastern Cape ( and Mpumalanga, where the eland has been reintroduced ( and the Cape willow grows humbly as part of the natural community of shrubs along streams.

Is capturing the African equivalent of not a worthy challenge for a new generation of naturalists with a heightened appreciation of the subtle connections among seemingly disparate continents and organisms?

Posted on September 13, 2021 00:38 by milewski milewski | 2 comments | Leave a comment

September 11, 2021

Finding expression in the face of the chacma baboon

The chacma baboon (Papio ursinus) is the largest (see and most southerly of monkeys. It is also exceptionally well-photographed, allowing us to illustrate its facial expressions.

There are at least four ways in which the face of the chacma baboon is so unlike the human face that we find difficulty in reading its expressions.

Males of the chacma baboon can fang-bare like carnivores ( However, the usual facial expression of masculine defensiveness and assertion is an exaggerated yawn, showing the pale eyelids ( and and and This is similar to a 'displacement activity' but serves to show the size and sharpness of the canines as a polite warning.

In the chacma baboon the expression of fear or appeasement is a grin/grimace (adult female: and

Whereas eye movements are extremely expressive in humans, they are extremely inscrutable in the chacma baboon. This is possibly because in humans status is gained mainly by sharing information, whereas in the chacma baboon status is gained mainly by withholding information ( and

The chacma baboon does possess pale ocular features, but these are located in keeping with a theme of non-divulgence and an avoidance of staring.

Firstly, adults of both sexes possess pale patches of fur on the otherwise bare rostrum, which seem designed to distract viewers from the eyes themselves. These can perhaps be thought of as 'false eyes' (see and and and and

Secondly, the pale eyelids are shown to express antagonism in both sexes. This can be the equivalent of a frowning stare but with the eyelids rather than the eyeballs doing the staring, or it can be a signal of appeasement. The half-closed eyes are accompanied by either raised eyebrows (assertive?) or flattened ears (submissive?). The following show the cringing expression in adult females: and

The 'neonatal makeup' of the chacma baboon ( and involves both a dark/pale contrast (blackish fur on the crown vs pale bare skin on the face of the newborn) and conspicuously reddish hues (particularly on the ears). This vivid colouration evokes the protective instinct of adults and juveniles so strongly that infants need no other facial expression for the first months of their lives.

Posted on September 11, 2021 02:56 by milewski milewski | 6 comments | Leave a comment

September 10, 2021

Focussing on the subtropical plains zebra

The subtropical plains zebra, currently included in subspecies burchellii of Equus quagga, narrowly escaped extermination in what is now Hluhluwe-imfolozi Park in Zululand ( and

From this source, the subtropical plains zebra has been reintroduced to other reserves in Zululand.

The special interest (please see several recent Posts) is that here we have the only surviving population formerly in contact with the extinct quagga (Equus quagga quagga). Given the genetic intergradation implied by this contact, it is here that we should seek founders for any attempt to retrieve phenotypic features of the extinct quagga.

It is remarkable, given the distance involved, that the tropical population of the plains zebra in and near Etosha National Park so resembles the subtropical plains zebra that it is called the same subspecies. The geographical disjunction is so great that we cannot assume that the genotypes are the same.

Yes, I am suggesting that the subtropical and tropical populations of what is currently called E. q. burchellii are geographically distant enough to have different genotypes despite their similar phenotypes.

In the context of this renewed interest in the subtropical plains zebra, I have chosen the following photos - all from Zululand - to show the appearance. Please bear in mind that the individual variation is far greater than that shown by this limited sample.

The following is also of interest:

Posted on September 10, 2021 20:09 by milewski milewski | 1 comment | Leave a comment

September 09, 2021

An unexpected convergence in colouration between giraffes and zebras

What do you notice about these two photos? and

Take it for granted that giraffes (Giraffa spp.) and zebras (four species of Equus) are similar: large ungulates with extreme colouration.

And that giraffes are by far the largest land animals with camouflage colouration, while zebras are so striped that the adaptive value of their colouration has been a major puzzle.

It seems safe to assume that, in both giraffes and zebras, the main functions of the overall colourations are to make the figures inconspicuous in some sense.

So, what in the above photos do I find remarkable?

Well, we have seen in previous posts about the moose (Alces alces) and various other ungulates, as well as various carnivores, that it is normal for largely inconspicuous animals to possess flags.

Flags are relatively small-scale patterns of colouration, subsumed within the overall colouration as long as the figure is stationary. However, they are large and dark/pale enough to become conspicuous once the animal moves in certain ways.

The intriguing convergence between giraffes (all species, both sexes, and both juveniles and adults) and zebras (albeit only one species, and only certain subspecies/individuals) is: both have unmarked, gleamingly pale ears, constituting auricular flags, when viewed from behind.

The auricular flags of giraffes and zebras are activated when the animals walk away intermittently. In this perspective there is a noticeable contrast between the whitish back-of-ear and the rest of the colouration, which is further accentuated by the normal movements of the ear pinnae. Such flagging presumably aids gregariousness because it makes it easy for individuals to keep track of each other's movements by means of the briefest glance. It also informs companions of any sudden attentiveness of an individual turning its eyes and ears towards something suspicious, thus promptly communicating any alarm.

The following, of Giraffa tippelskirchi tippelskirchi, shows how thoroughly camouflaged giraffes can seem by virtue of their colouration:

However, in all giraffes the back-of-ear is exempt from spotting: and

Furthermore, the short fur on the back-of-ear seems to possess a sheen, making it even more eye-catching in certain lights. The following show illuminations where this sheen effect is not apparent: and and

The following show how conspicuous the auricular flag of giraffes can be even at considerable distance: and and and and

Turning to zebras:

In three of the four species of zebras, the back-of-ear has complicated colouration:

Equus grevyi: and and and

(the following nicely compare the front- and back-of-ear of E. grevyi: vs

Equus hartmannae: and

Equus zebra: and

However, in several subspecies of the plains zebra (Equus quagga) there is a tendency for the back-of-ear to be mainly whitish (e.g. E. q. burchellii and

The basic pattern in this species, which varies according to subspecies and individual, is In several subspecies this can hardly qualify as an auricular flag because the whitish feature is too small.

However, in two northern subspecies (E. q. borensis and E. q. isabella) the whitish area covers most or all of the back-of-ear, and the ear pinna is unobstructed because the mane is particularly short ( and and and and and and and

In several other subspecies, there is individual variation:

Equus quagga burchellii and and and

Equus quagga chapmani and and and

Equus quagga boehmi and and and and and

The only extant subspecies in which I have yet to see any individual with an auricular flag is E. q. crawshayi ( and and

In the case of the extinct quagga (E. q. quagga) nobody has examined the museum specimens for this, but my impression from photos is that there was no auricular flag ( and If so, this is yet another way in which the extinct quagga was not merely an extrapolation of the trend in colouration from E. q. chapmani to E. q. burchellii.

Posted on September 09, 2021 22:36 by milewski milewski | 3 comments | Leave a comment

Capricious subspeciation in the plains zebra, part 2: a new suggestion re the extinct quagga

What if inappropriate founders were chosen for the Quagga Revival Project, based on incorrect assumptions?

Please see my last two Posts.

The idea behind the Quagga Revival Project has been that any capacity for re-expression of the phenotype of the extinct E. q. quagga would likely occur in the geographically adjacent subspecies, namely Equus quagga burchellii. And so individuals were chosen and captured from populations of E. q. burchellii, starting the process of selective breeding.

However, E. q. burchellii has an oddly disjunct distribution: Zululand vs northern Namibia-southwestern Angola. These areas are 1600 km apart, and the southeasternmost sites are twice as far from the equator (30 vs 14 degrees South) as the northwesternmost sites. What if these two populations are significantly different genetically, with that in Zululand having the most in common (albeit not necessarily expressed in the wild phenotype) with the extinct quagga?

In order to see that northern Namibia might have been an unsuitable source of founders - because it is so far from the distribution of the extinct quagga - we must for a moment discount any taxonomic controversy.

Whether we call the northern Namibian population burchellii or not, this population apparently extended northwards to about 14 degrees South, in southwestern Angola (see file:///C:/Users/Antoni%20Milewski/Downloads/Beja2019_Chapter_TheMammalsOfAngola%20(1).pdf). If so, then capturing individuals in the Etosha area, as was done for the Quagga Revival Project, meant resorting to a gene-pool living up to 2000 km from the nearest population of the extinct quagga.

Whether we call the Zululand population E. q. burchellii or not, this form lived at most a few hundred km from the nearest population of the extinct quagga, i.e. at least four times closer.

This is what I suspect.

Before European arrival, there were five genetically different types of the plains zebra in southern Africa south and west of the Zambezi River. Their ranges (see were:

1) Western Cape, Eastern Cape and the southern part of Northern Cape provinces, extending to southern Free State province (extinct quagga),

2) northern Free State province to northern Kwazulu-Natal province,

3) Mpumalanga and Limpopo provinces and northwards as far as northern Botswana (nobody quibbles with calling this E. q. chapmani),

4) North West province at the southern edge of the Kalahari (an extinct population from which the type specimens for both burchellii (see and and its junior synonym antiquorum were collected), and

5) Namibia, extending to southwestern Angola.

Of these, the one geographically closest to the extinct quagga was 2).

If it were up to me to start the Quagga Revival Project from scratch, I would capture founders only in Zululand, and I would prioritise individuals with the darkest ground-colour rather than individuals with minimal striping on the legs and hindquarters. I would then breed selectively for overall darkness before trying to reduce the striping.

Posted on September 09, 2021 00:22 by milewski milewski | 1 comment | Leave a comment