25 de septiembre de 2021

Like-size dog vs donkey: exemplifying differences in pace of life

(writing in progress)

How similar can the smallest-bodied breeds of the donkey (https://soumo.eu/cute-donkeys-10/ and https://www.guinnessworldrecords.com/world-records/shortest-donkey) be in body mass to the largest-bodied breeds of the domestic dog?(https://es.123rf.com/photo_654533_giant-dog-and-woman.html and https://imgur.com/gallery/OhYPphE and https://www.distractify.com/p/wolfdog-kill-shelter-rescue and https://www.dreamstime.com/beautiful-woman-big-fluffy-dog-nature-caucasian-guard-sheepdog-image212481454)

(see https://www.dailymail.co.uk/video/news/video-1609300/Video-Tiny-Tim-Mini-Donkey-enjoys-playing-pillows.html and https://www.youtube.com/watch?v=MIQKlHSD89E and https://www.alamy.com/old-man-riding-a-donkey-in-a-mountain-village-image158358068.html and https://travel.mongabay.com/china/images/china_104-8142.html)

And how much do these convergent pets, one derived from large ancestors and the other derived from small ancestors, converge in their pace of life?

Body mass is one of the most important descriptors of any organism. This is partly because, other factors being equal, the smaller the body the faster its 'pace of life'.

By pace of life, I mean the rate at which the organism uses resources, and the rate at which it reproduces, matures, and reaches senility.

Donkey g p https://www.researchgate.net/publication/276212655_Factors_affecting_pregnancy_length_and_phases_of_parturition_in_Martina_Franca_jenny

Dog g p https://pubmed.ncbi.nlm.nih.gov/8122353/

Anotado en sábado, 25 de septiembre de 2021 a las 08:51 AM por milewski milewski | 1 comentario | Deja un comentario

24 de septiembre de 2021

Two disparate survivors of the Pleistocene megafauna in the Americas

Everyone knows that, at the end of the Pleistocene about 11,000 years ago, most of the large species of mammals in the Americas went abruptly extinct.

However, who understands why the few exceptions managed to survive?

Let us adopt a criterion of 200 kg, which is about the body mass of adult females of the sable antelope (Hippotragus niger,
https://upload.wikimedia.org/wikipedia/commons/3/3a/Sable_%28Hippotragus_niger%29_female_crossing_the_road_%2816635641913%29%2C_crop.jpg and https://animaldiversity.org/accounts/Hippotragus_niger/pictures/collections/contributors/susan_hoffman/sable/), adult females of the eastern white-bearded wildebeest (Connochaetes albojubatus, https://www.flickr.com/photos/gridarendal/31251992874 and https://es.123rf.com/photo_62252521_mother-and-baby-wildebeest-in-amboseli-park-kenya.html), and adult females of two subspecies of the Asian wild ass (Equus hemionus onager, https://upload.wikimedia.org/wikipedia/commons/a/a3/Onager_Asiatischer_Wildesel_Equus_hemionus_onager_Zoo_Augsburg-11.jpg and https://printmeposter.com/poster_photo__176560507.html and Equus hemionus khur https://www.researchgate.net/figure/Figure-41-Indian-wild-ass-on-the-agro-pastoral-landscape-Source-Parmar-2016_fig25_330576869).

According to this criterion of body size:

Which species of the Pleistocene megafauna, with adult female body mass exceeding 200 kg, survived in the Americas?

More precisely, which of these species were present on this supercontinent 13,000 years ago, and remain today?

The answer is only two species: the moose (Alces alces https://en.wikipedia.org/wiki/Moose and https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-020-07208-3#:~:text=Modern%20moose%20(Alces%20alces)%20first,of%20the%20Pleistocene%20%5B17%5D) in North America and Baird's tapir (Tapirus bairdii https://en.wikipedia.org/wiki/Baird%27s_tapir and https://www.dreamstime.com/stock-images-baird-s-tapir-adult-strolling-water-image31211024#_ and https://www.dreamstime.com/stock-images-baird-s-tapir-adult-strolling-water-image31211024#_) in central and South America.

What is remarkable about these two survivors is that, although they both have proboscis-like facial specialisations (https://www.researchgate.net/publication/236183185_Structural_and_functional_comparison_of_the_proboscis_between_tapirs_and_other_extant_and_extinct_vertebrates), they are otherwise disparate in body form, habitat, life history strategy and anti-predator adaptations.

The moose is not just a 'Pleistocene giant' but combines the following three attributes. It is unusually versatile in its foraging behaviour, unusually fecund for its body size (https://pub.epsilon.slu.se/11098/1/malmsten_j_140401.pdf and https://link.springer.com/article/10.1007/BF00328601 and http://www.adfg.alaska.gov/static/education/educators/curricula/alaskawildlifecurriculum/pdfs/how_fast_can_a_moose_population_grow.pdf), and unusually adept at self-defence by means of kicking.

The fecundity of the moose seems to be a fortuitous - and fortunate - facet of its adaptation to a habitat, the boreal forest, which even during the Ice Ages was subject to episodic wildfires. A capacity for rapid reproduction allowed the moose to fluctuate in population with the cycle of post-fire regeneration - and then allowed it to survive the mysterious onslaught that defeated all other species of ungulates of its body mass or more in North America.

Baird's tapir has a different profile. It belongs to a family of 'living fossils', archaic forms originating before the Pleistocene and surviving mainly by virtue of the refugial nature of its habitat: dense forest on steep slopes and with sparse populations of other large prey. Baird's tapir was not particularly adapted to either the Ice Ages or pressure from predators, but happened to be relatively inaccessible.

The difference in the reproductive rates of moose and Baird's tapir can be seen in gestation period (243 days vs 400 days) and litter size (opportunistic twinning vs only one newborn per birth). And the difference in braininess between these two survivors is typical of the contrast between versatile and archaic forms: relative to body mass, the brain mass of the moose is about double that of Baird's tapir (file:///C:/Users/Antoni%20Milewski/Downloads/rspb20053283s04.pdf and https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1560022/).

Footnote:
Although some individual adult females of the muskox (Ovibos moschatus, see https://www.researchgate.net/publication/238035671_Body_composition_of_muskoxen_Ovibos_moschatus_and_its_estimation_from_condition_index_and_mass_measurements) and the South American tapir (Tapirus terrestris) exceed 200 kg, these species are excluded on the basis of averages. The North American bison (Bison bison) does not qualify because as a species it evolved within the Holocene, despite belonging to a genus already present in the Pleistocene.

Anotado en viernes, 24 de septiembre de 2021 a las 08:46 AM por milewski milewski | 0 comentarios | Deja un comentario

A synopsis of recent insights into domestic animals

(in no particular order)

Perhaps the main function of the donkey has been to shape the ancestral wild asses into a form (https://luckythreeranch.com/site/wp-content/uploads/Romulus_and_Cara02.jpg) suitable for interspecific hybridisation (with the horse).

One of the most puzzling aspects of the llama and alpaca is their absence from the pampas of Buenos Aires Province (https://en.wikipedia.org/wiki/Buenos_Aires_Province#/media/File:Buenos_Aires_Province_in_Argentina_(+Falkland).svg) at the time of European arrival.

The black-and-tan pattern of the domestic dog may be the wild-type colouration (https://www.facebook.com/KelpieHungary/photos/2643922185661473) of an extinct, jackal-like species distinct from the wolf.

The donkey (https://www.youtube.com/watch?v=K6arOJijpEo and https://www.dreamstime.com/stock-photo-donkey-face-green-summer-pasture-ears-back-image42747898 and https://www.pinterest.com.au/pin/267753140321010215/ and https://www.enstarz.com/articles/123259/20151129/amazing-stories-you-would-not-believe-these-two-animals-are-best-of-friens-video.htm and https://www.alamy.com/brown-wild-burro-in-the-black-hills-in-south-dakota-with-eyes-closed-and-mouth-open-image402045730.html) may be convergent with the moose (https://www.gettyimages.com.au/detail/news-photo/staff-photo-by-fred-j-field-mon-mar-10-2003-maine-game-news-photo/481158351?adppopup=true and https://marydonahue.org/wp-content/uploads/2020/12/nps-photo-agitated-moose-when-a-moose-is-stressed-it-will-lay-its-ears-back-along-its-head-and-its-hackles-will-rise.jpg and https://www.alamy.com/cow-moose-squinting-with-ears-back-image333665017.html and https://www.dreamstime.com/stock-photo-two-young-moose-elk-alces-alces-flatten-ears-arguing-flattening-green-surroundings-forest-image94341624) in displaying an auricular semet in antagonism.

Selective breeding of the dingo has altered the infantile/juvenile colouration (https://www.ladbible.com/news/latest-ultra-rare-pure-bred-alpine-dingo-puppy-discovered-in-australia-20200922) instead of the adult colouration.

Canis differs from Felis in that the fang-baring is an adult expression in the former (https://www.reddit.com/r/photoshopbattles/comments/53hzgl/psbattle_snarling_jackal/) but already developed in infancy in the latter (https://www.alamy.com/stock-image-cougar-and-snarling-25-month-old-kitten-puma-concolor-montana-usa-162697079.html).

Further selective breeding of the domestic cat could, in principle, produce a breed with warning colouration on the inner foreleg (https://www.mindenpictures.com/stock-photo-african-wild-cat-felis-lybica-adult-walking-kalahari-gemsbok-national-naturephotography-image80038718.html).

The dingo and the Maasai donkey are convergent in that neither conforms to the categories wild, domestic or feral, and both can instead be called domensal.

The Catalan breed of the donkey has the first recorded instance of an anthropogenic frontal bleeze (https://www.shutterstock.com/nb/image-photo/funny-black-donkey-white-tummy-nose-1583673382).

Anotado en viernes, 24 de septiembre de 2021 a las 05:24 AM por milewski milewski | 0 comentarios | Deja un comentario

23 de septiembre de 2021

How did the donkey get a frontal bleeze?

One of the most conspicuous features of the adaptive colouration of wild ungulates is the frontal bleeze (e.g. Damaliscus pygargus phillipsi https://www.zoochat.com/community/media/blesbok-damaliscus-pygargus-phillipsi.487604/).

This is a pale/dark feature so obvious that it divulges the presence of the ungulate to scanning predators, even at a distance and even if the figures remain stationary (https://www.alamy.com/stock-photo-herd-of-blesbok-in-field-africa-87078020.html).

As discussed in previous Posts, bleezes have evolved presumably because, in the life history strategy of certain gregarious species of open environments, it is more important to remain easily monitored by companions than it is to hide from predators.

Bold markings occur also in domestic ungulates, but usually not in the form of bleezes. They function differently, being a mainly inadvertent result of selective breeding. Humans can protect their livestock from predators, so natural selection for wild-type colouration is relaxed. Furthermore, it suits herders to be able to spot strays easily; and piebald, individualised markings are regarded as aesthetically pleasing by pastoral cultures.

The distinction between wild-type and domestic colouration, in these conspicuously pale or dark patches, is a matter of bilateral symmetry and individual consistency. Markings produced by domestication tend to be erratic (e.g. https://longmeadowrescueranch.org/barnbuddies/geppetto-2/).

However, there is an apparent exception in the case of the donkey (Equus asinus). In certain large-bodied Iberian breeds such as the Balearic (https://en.wikipedia.org/wiki/Balearic_donkey) and the Catalan (https://en.wikipedia.org/wiki/Catalan_donkey), a frontal bleeze has arisen in domestication from ancestors which, as far as we know, lacked any bleeze.

How and why has wild-type colouration come to be 'reinvented' anthropogenically in this case?

The novel bleeze seen in Iberian breeds of the donkey consists of a strikingly pale muzzle on an otherwise dark face (https://fineartamerica.com/featured/wild-burro-nevada-jan-lewis.html and https://www.inaturalist.org/observations/48410657 and https://www.inaturalist.org/observations/45581467 and https://www.dreamstime.com/stock-photo-wild-black-donkey-pasture-burro-standing-looking-ahead-alert-expression-full-body-side-view-image58393196).

In this configuration, it is the dark aspect that is different from the wild ancestors. All species of wild asses have pale on the muzzle, but this is hardly conspicuous because the rest of the face is usually medium in tone:

Equus kiang
https://stock.adobe.com/bg/search?k=onager&asset_id=296475961 and https://www.projectnoah.org/spottings/394553031 and https://www.istockphoto.com/photo/wild-ass-kiang-gm157747840-22292105 and https://www.istockphoto.com/photo/kiang-gm462912429-32514774 and https://www.researchgate.net/figure/An-adult-male-Equus-kiang-subspecies-kiang-in-summer-coat-from-eastern-Ladakh-India_fig1_262137189

Equus hemionus onager
https://stock.adobe.com/bg/search?k=onager&asset_id=61074577 and https://stock.adobe.com/bg/search?k=onager&asset_id=112934812

Equus hemionus kulan
https://stock.adobe.com/bg/search?k=onager&asset_id=291249306

Equus hemionus khur
https://hive.natureinfocus.in/photo_sharing/indian-wild-ass-2

Equus africanus somaliensis
https://focusedcollection.com/165616364/stock-photo-somali-wild-ass.html and https://pixabay.com/photos/somali-wild-ass-desert-negev-israel-4764744/

Because the dark on the face is merely part of an overall darkness in the breeds in question, the puzzle resolves to: why did selective breeding of the donkey in Spain favour dark overall colouration instead of the irregular patchwork typical of domestic livestock?

In order to answer this, it is first necessary to consider the importance of the donkey in the breeding of mules (see https://www.mulemuseum.org/history-of-the-mule.html and https://en.wikipedia.org/wiki/Mule).

A poorly-appreciated aspect of the donkey is that it is unique among domestic animals in having been selectively bred mainly for the purposes of producing an interspecific hybrid.

Of course, it is true that the donkey, in the form of small-bodied breeds, has been economical for poor people in many countries since ancient times. However, production of mules (hybrids produced by males of the donkey and females of the horse, e.g. https://luckythreeranch.com/site/wp-content/uploads/Draft-Mule.jpg) has for an equally long time been where real profits lay, to the benefit of politically powerful - and often belligerent - elites.

Thus it has been the production of not the working breeds of the donkey but rather suitable sires for large, strong, sombre-looking mules that has long been the main incentive behind selective breeding of the donkey (see https://www.defensemedianetwork.com/stories/the-virtues-of-stubbornness-mules-at-war/). This means a particular demand for breeds of the donkey which combine an imposing body size (average adult male body mass preferably exceeding 400 kg, e.g. https://fuives.com/en/ and https://luckythreeranch.com/site/wp-content/uploads/Mammoth-Donkey.jpg) and the sort of colouration that means business.

Is it mere coincidence that the front-of-ear pattern - which risks giving the donkey a comical appearance - has been muted in the Catalan breed? (https://www.istockphoto.com/photo/huge-furry-catalan-donkey-pasturing-gm1153043674-313029467 and https://stock.adobe.com/search?k=%22catalan+donkey%22&asset_id=81299484)

By the late eighteenth century it was mainly Spain and southern France which prevailed in the market for males of the donkey for the purposes of equine hybridisation (see https://en.wikipedia.org/wiki/List_of_Iberian_donkey_breeds). And it was - according to my hypothesis - in this context that a specialised colouration was chosen for the Catalan breed in particular (https://www.alamy.com/catalan-donkey-equus-asinus-f-asinus-image9523565.html).

If my interpretation is correct, the frontal bleeze in the donkey is to all intents and purposes redundant in adaptive terms. It is merely the inadvertent result of the phenotypic persistence of the paleness on the muzzle (which has passed under the radar of selective breeding because it hardly detracts from the looks of mules) combined with the otherwise relatively uniform darkness of breeds selected to look as credible as possible for the siring of large, dark, capable-looking mules serving powerful political agenda.

In other words: the Iberian breeds can be thought of as wearing what is not so much a lookalike-colouration for wild ungulates, but more an asinine equivalent of a 'business suit'.

Anotado en jueves, 23 de septiembre de 2021 a las 01:17 AM por milewski milewski | 5 comentarios | Deja un comentario

21 de septiembre de 2021

Why does the donkey have big ears?

Everyone knows that the donkey (Equus asinus) tends to have large ears (https://www.facebook.com/Donkeywhisperer/photos/my-what-big-ears-you-haveoften-we-get-the-sweetest-inquiries-from-children-askin/1672642076086866/). However, who understands the adaptive value of large ears in equids, and why this seems to have been emphasised by domestication?

The ear consist of an outer ear, i.e. the ear pinna, and an inner ear, i.e. the capsule of the skull at the base of the ear-hole - called the auditory (or tympanic) bulla. The inner ear is remarkably small in equids (see http://www.ionhealing.com/sagehillCMK/Equine%20Skull.html), indicating limited hearing.

A small inner ear makes sense because all wild equids - which live in open environments - rely more on vision than on hearing. Their eyes are proportionately even larger than those of coexisting ruminants. And the wild ancestors of the donkey lived in particularly open environments in the semi-deserts of North Africa.

Therefore, if it is adaptively significant that the ear pinnae are larger in the donkey than in e.g. the horse (Equus caballus), this is likely to be in thermoregulation rather than hearing.

And, indeed, the inner ear is similarly small in donkey and horse (https://www.kythera-family.net/en/natural-history-museum/mammals/donkey-skull and https://www.shutterstock.com/nb/image-photo/close-ups-propped-sun-bleached-donkey-1618690138 compared with https://www.deviantart.com/ratrinadragon/art/Trick-the-pony-skull-244132670 and https://www.worthpoint.com/worthopedia/pony-skull-245944474).

So, do the ears of the donkey radiate excessive heat from the body?

It does seem true that, whereas the horse sweats a lot in hot weather, the donkey sweats little. Where the horse relies mainly on evaporative cooling, the donkey may rely partly on radiative cooling.

And, partly because its normal body temperature is only 37 degrees Celsius (compared to 38 degrees Celsius in the horse), the donkey has more leeway than the horse to heat up during the day before cooling down again at night (see https://www.researchgate.net/publication/283248068_Heat_Tolerance_in_Donkeys_and_Mules#:~:text=Compared%20to%20the%20local%20donkeys,absorbs%20more%20incidental%20solar%20radiation.).

But what remains puzzling is that the ear pinnae of the donkey are so furry. Compare Lepus (https://www.alamy.com/close-up-portrait-of-a-black-tailed-jackrabbit-image371183426.html) with an extreme individual of the donkey (https://www.dreamstime.com/stock-photo-donkey-farm-virginia-image10366740).

Semi-deserts tend to be cold at night, and the donkey cannot shelter in burrows, or fold its ears flat, in the way of the fennec fox (https://en.wikipedia.org/wiki/Fennec_fox) or the long-eared jerboa (https://25hournews.com/news/night-loving-mouse-long-eared-jerboa-mouse-family-of-the-dipodidae-3167).

For the furry ear pinnae of the donkey to radiate much heat, the fur would have to be able to part, exposing panels of bare skin. Nobody seems to have observed this - possibly because nobody has had a search-image for it.

The mechanism of piloerection is, however, evident in another ungulate adapted to semi-deserts, the large ears of which are particularly well-photographed: the steenbok (Raphicerus campestris).

In what is presumably cool weather, the fur on the front-of-ear folds down (https://gurushots.com/photo/250bc6ae4df24cd02509bb2ece7850d2 and https://gurushots.com/photo/88519d81993d57aa9d1be3a4066ec609 and https://gurushots.com/photo/42758df999a3df826daf6b46c55ffd8e). But in hot weather, the same fur erects to show the somewhat bloodshot bare skin (https://www.flickr.com/photos/piazzi1969/11253299393 and https://akeke.blog/sydafrika-2016/#jp-carousel-2914 and https://cdn.hungryonion.org/original/3X/f/3/f359c1537c964d5330ec57d3826c7a373b9f86be.jpg). The clearest photo of all can be found by scrolling within https://www.cultafrica.net/home/tours_top/africa_unusial.html.

Can readers imagine a similar mechanism in these ears? https://www.shutterstock.com/nb/image-photo/donkey-outdoors-nature-under-blue-sky-1689196276 and https://www.dreamstime.com/stock-photo-donkey-ears-big-face-forward-to-encourage-us-to-listen-up-image87723778 and https://www.dreamstime.com/two-pairs-donkey-ears-over-blue-sky-image181826262 and https://www.dreamstime.com/beautiful-ears-donkey-head-close-up-donkey-big-ears-thoroughbred-shaggy-sky-image229151207.

And please bear in mind that the ears of the donkey tend to look larger than they really are, relative to body mass.

The compendium of photos below compares the donkey, the Somali wild ass (Equus africanus somaliensis), and Hartmann's zebra (Equus hartmannae, which lives with the steenbok in southern African semi-desert).

You can see that the ear pinnae are moderately large in both the Somali wild ass and Hartmann's zebra. And many individuals of the donkey have ear pinnae of similar, moderate size relative to the forehead or the body. What makes the ears look outsize in the donkey is the shortening of the legs by domestication (https://www.dreamstime.com/stock-photography-walking-donkey-image16023212 and https://www.dreamstime.com/donkey-standing-sea-animal-four-legs-large-ears-used-loading-mammalian-animal-donkey-standing-sea-image202864961).

In summary:

The ear pinnae of the donkey are not much larger, relative to body mass, than in wild species of Equus which live in semi-deserts with limited water to drink. Their main function is radiation of excessive body heat, rather than particularly acute hearing. Naturalists: please test this by looking for evidence that the fur on the front-of-ear can open up in hot weather to expose panels of somewhat bloodshot bare skin.

Equus asinus

https://www.shutterstock.com/nb/image-photo/beautiful-healthy-young-donkey-head-shot-1689196273

https://www.dreamstime.com/stock-photo-smiling-donkey-pasture-image44455842

https://www.shutterstock.com/nb/image-photo/happy-donkeys-on-streets-maio-island-1774073948

https://wallsheaven.co.uk/wall-murals/burros-A111600542

https://wallsheaven.co.uk/wall-murals/mannar-donkey-in-kalpitiya,-sri-lanka-D842155545

https://wallsheaven.co.uk/wall-murals/donkey-or-ass-on-natural-environment.-C315737899

https://www.dreamstime.com/royalty-free-stock-images-spotted-grey-donkey-image12259539

https://www.shutterstock.com/nb/image-photo/cute-puppy-donkey-white-paws-277371563

https://www.shutterstock.com/nb/image-photo/donkey-153759464

https://wallsheaven.co.uk/wall-murals/donkey-on-natural-environment.-A057620822

Equus africanus somaliensis

https://www.shutterstock.com/nb/image-photo/somali-wild-donkey-equus-africanus-inhabits-417105889

https://www.vecteezy.com/photo/715917-somali-wild-ass-equus-africanus-in-israeli-nature-reserve

https://www.zoochat.com/community/media/equus-asinus-somalicus-somali-wild-ass-male.221844/

https://www.zoochat.com/community/media/equus-asinus-somalicus-somali-wild-ass-male.221848/

https://www.zoochat.com/community/media/equus-asinus-somalicus-somali-wild-ass-male.221846/

https://www.zooborns.com/.a/6a010535647bf3970b019afff0392d970c-popup

https://wallsheaven.co.uk/wall-murals/somali-wild-donkey-(equus-africanus)-in-nature-reserve-of-the-middle-east.-this-species-is-extremely-rare-both-in-nature-and-in-captivity-C345686901

https://www.zooborns.com/.a/6a010535647bf3970b019affeffb27970b-popup

Equus hartmannae

(comparison with Equus quagga burchellii: https://upload.wikimedia.org/wikipedia/commons/b/b0/Equus_quagga_burchellii_%26_Equus_zebra_hartmannae_-_Etosha_2015.jpg)

https://www.gettyimages.com.au/detail/photo/hartmanns-mountain-zebra-equus-zebra-hartmannae-royalty-free-image/508502127

https://www.alamy.com/stock-photo-hartmanns-mountain-zebra-damaraland-namibia-102865344.html

https://animals-are-cool.fandom.com/wiki/Hartmann%27s_Mountian_Zebra?file=Hartmannsmountainzebra1_327w.jpg

https://www.africahunting.com/media/hartmanns-zebra-mountain-zebra.2847/

https://disneyparks.disney.go.com/blog/2020/04/disneymagicmoments-introducing-asha-a-hartmanns-mountain-zebra-foal-at-disneys-animal-kingdom-theme-park/

Equus hemionus

https://wallsheaven.co.uk/wall-murals/the-onager-(equus-hemionus)-is-a-brown-asian-wild-donkey-inhabiting-nature-reserve-park-near-eilat-B692591540

https://wallsheaven.co.uk/wall-murals/the-turkmenian-kulan,-equus-hemionus-kulan,-is-a-rare-asian-donkey-A063742172

Anotado en martes, 21 de septiembre de 2021 a las 08:29 PM por milewski milewski | 5 comentarios | Deja un comentario

20 de septiembre de 2021

An extinct canid hiding in plain sight in the domestic dog?

Everyone knows that a certain black-and-tan pattern occurs again and again - either on an individual basis or as the colouration typical of the breed - in otherwise diverse breeds of the domestic dog (Canis familiaris).

These range in body size from the chihuahua (https://www.askideas.com/55-very-beautiful-chihuahua-dog-photos-and-pictures/) to the rottweiler (https://www.petbarn.com.au/petspot/app/uploads/2015/01/23.-Rottweiler.jpg) and beyond...

...and in body shape from the daschund (https://www.playbarkrun.com/dachshund-colors/ and https://www.freepik.com/premium-photo/black-tan-dachshund-walking-nature_10166528.htm and https://www.rover.com/blog/breeds/dachshund/ and https://www.dachshund-owner-guide.com/dachshund-colors.html#gallery[pageGallery]/1/) to the afghan hound (https://www.alamy.com/a-profile-view-of-a-healthy-beautiful-grizzle-black-and-tan-afghan-hound-walking-on-the-grass-looking-happy-and-cheerful-persian-greyhound-dogs-are-slim-and-slender-with-a-long-narrow-head-long-silky-coat-and-curly-tail-image276649468.html).

However, what is poorly appreciated is that the black-and-tan (or in some cases 'chocolate-and-cream' or 'chocolate-and-tan') pattern is one of the most significant and unexplained aspects of the domestic dog.

This pattern is bilaterally symmetrical and forms an integral and coherent system of markings connecting the head, chest, legs and hindquarters (https://doggiedesigner.com/black-and-tan-dog-breeds/). The system includes vestigial/incipient forms of adaptive features typical in wild mammals, such as a frontal flag (https://www.dreamstime.com/black-tan-mixed-large-breed-puppy-standing-full-length-photo-black-tan-color-mixed-large-breed-puppy-dog-standing-image114250081 and https://www.inaturalist.org/observations/89243136) and a buttock flag (https://www.shutterstock.com/image-photo/black-tan-rottweiler-puppy-standing-on-1635788887 and https://www.inaturalist.org/observations/92095076).

(Please note that the pattern https://www.facebook.com/806111259438680/photos/black-and-tan-german-shepherds-the-black-tan-german-shepherd-dogs-can-be-rich-bl/807666499283156/ in breeds such as the German shepherd - although often confusingly called black-and-tan - is different, and irrelevant in this context.)

So, what is particularly significant about the black-and-tan pattern in the domestic dog?

Well, could it be that here we have a virtually complete representation of the colouration of an extinct and unnamed wild species of Canis which contributed to the ancestry of this, the oldest of all domestic species?

Many currently believe that the wolf (Canis lupus) is the main or sole ancestor of the domestic dog (e.g. see https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0125759 and https://en.wikipedia.org/wiki/Origin_of_the_domestic_dog). And this seems a safe assumption in the case of at least a few breeds such as the saarloos wolfhound (https://www.zooplus.co.uk/magazine/dog/dog-breeds/saarloos-wolfhound), which lack the black-and-tan pattern in any individual (https://www.petguide.com/breeds/dog/saarloos-wolfhound/).

However, the trouble is that the black-and-tan colouration is unknown in either the wolf or any other of the living wild species of Canis.

For the black-and-tan pattern to have appeared in descendents of solely the wolf, this entire system of features would have had to arise as a single mutation. Furthermore, the pattern would have had to be strongly preferred by humans during subsequent selective breeding.

These conditions seem implausible for several reasons.

Firstly, the black-and-tan pattern is 'wild-type' in its regular configuration (e.g. see https://thehappypuppysite.com/rottweiler-temperament/), quite unlike the haphazard mutational features typical of many species of domestic mammals and birds.

Secondly, the black-and-tan pattern is recurrent and persistent among breeds regardless of extreme modification of body size and proportions. This conservatism indicates a deep ancestral feature, not one bred into the dog by domestication.

Thirdly, the black-and-tan pattern shows the same kind of subtle individual variation as do wild-type colourations in mammals in general.

Fourthly, the black-and-tan pattern remains in the populations of 'primitive' or 'retrogressive' relatives of the domestic dog, particularly the dingo.

Fifthly, where any irregular and asymmetrical marking occurs in combination with the black-and-tan pattern, the former is superimposed on the latter, not the other way round (https://hdwallpapers.cat/wallpaper/smooth-collie-katie-herding-breed-black-tan-6Bu2.jpg).

And sixthly, the black-and-tan pattern has some aesthetic appeal to many persons but not more so than various other, more typically domestic, patterns, such as the patchwork of tones seen in the border collie (http://www.vetstreet.com/dogs/border-collie#1_izc4ixoo and https://www.deviantart.com/kimptone/art/NEW-Border-Collie-Colour-Chart-117559446).

What all of this suggests is that the black-and-tan pattern is derived not from the wolf but from a different, extinct ancestor. This was possibly a jackal-like species living in Eurasia in the Pleistocene, which left few recognisable bones.

Let us look with fresh eyes, then, at working breeds such as the kelpie, which have retained/regained medium body size and a generalised body shape (https://www.101dogbreeds.com/wp-content/uploads/2014/12/Black-and-Tan-Australian-Kelpie.jpg and https://www.cleverkelpies.com/tracker-cosmo and http://jembellafarm.blogspot.com/2016/06/casterton-kelpie-muster.html and http://gibbinshatleykelpie.blogspot.com/2009/03/australian-kelpie.html) similar to those of most wild species of Canis.

Is it not plausible that the overall appearance of the kelpie resembles this extinct species?

The likeness I am suggesting is, of course, phenotypic rather than genotypic. Nobody should doubt the complexity of selective breeding, over 15,000 years or more, that separates the kelpie from any extinct ancestor or co-ancestor. And hybridisation with the wolf remains likely as part of this process.

However, what I am suggesting is that - by accident rather than by design - the overall phenotypic trajectory may have circled back to the appearance of an extinct species separate from the wolf.

And - if we dare to hypothesise boldly enough to create a new search-image for this extinct species in the fossil record and in genetic analyses - could we even apply a working name of 'Canis rubronegrus'?

Further illustrations:

https://www.adoptapet.com/pet/20937390-barrie-ontario-irish-wolfhound-mix

https://www.inaturalist.org/observations/87511931

Saint Bernard
https://unsplash.com/photos/YRUzuSC48Zs

Tibetan mastiff
https://www.purina.com.au/dogs/breeds/tibetan-mastiff#.YUie0ivitDM

Coonhound
https://thehappypuppysite.com/black-and-tan-coonhound/ and https://www.hotdogpetphotography.com/dogs/dog-day-black-tan-coonhound/ and http://www.vetstreet.com/dogs/black-and-tan-coonhound

English toy terrier
https://www.bing.com/images/search?view=detailV2&ccid=eqgfCumX&id=91E21746EA717AC4263374BB84B386A50F8EB1F9&thid=OIP.eqgfCumXY_r9emoO8h6gSAElDU&mediaurl=https%3a%2f%2fwww.mypetzilla.co.uk%2ffiles%2f6114%2f7913%2f5836%2fEnglish-Toy-Terrier.jpg&exph=434&expw=600&q=english+toy+terrier&simid=608036304034995332&FORM=IRPRST&ck=C2DCD2D1038F55791232B8830E3B8DF1&selectedIndex=27&ajaxhist=0&ajaxserp=0

Anotado en lunes, 20 de septiembre de 2021 a las 01:43 PM por milewski milewski | 2 comentarios | Deja un comentario

19 de septiembre de 2021

Juvenile makeup as a distinctive feature of the dingo

Everyone knows one of the most obvious differences between the dingo and the domestic dog (Canis familiaris).

This is that most individuals of the dingo have plain colouration (https://www.inaturalist.org/observations/37808149) with whitish around the mouth (https://www.shutterstock.com/nb/image-photo/close-dog-dingo-animal-zoo-mouth-1188179503 and https://www.shutterstock.com/nb/image-photo/dingo-sanctuary-melbourne-australis-1973462144 and https://www.alamy.com/portrait-of-dingo-dog-lupus-dingo-in-australia-image177730747.html and https://www.shutterstock.com/nb/image-photo/dingo-sanctuary-melbourne-australia-1976693408).

Because this facial pattern, standard in the dingo, is shared with all the wild species in the genus Canis, it helps to give an impression that the dingo has partly reverted to wild-type colouration.

The following show the whitish facial feature in all the wild species of Canis:

Canis aureus https://www.istockphoto.com/photo/golden-jackal-close-up-portrait-gm1226896827-361639214

Canis anthus https://www.shutterstock.com/nb/image-photo/african-golden-wolf-canis-anthus-known-1256673595

Canis latrans https://www.flickr.com/photos/mattknoth/4841118345

Canis lupus https://lindaursin.net/wp-content/blogs.dir/26/files/2018/09/wolf-face.jpg

Canis simensis https://www.agefotostock.com/age/en/details-photo/ethiopian-wolf-canis-simensis-in-the-bale-mountains-national-park-the-ethiopian-wolf-is-the-rarest-of-the-wild-dogs-or-wolves-and-strictly-protected-the/X8C-1097123/1

However, what is not generally realised about the dingo is that it differs from both the domestic dog and wild species of Canis in infantile and juvenile colouration.

More particularly, it is only the dingo that goes through a series of ontogenetic changes in facial colouration which last perhaps half of its usual lifespan of about eight years.

In other forms of Canis including most breeds of the domestic dog, such ontogenetic changes hardly occur. In the few breeds with pale faces as adults, the face is already pale at birth. In the many breeds with dark faces as adults, the face is already dark at birth.

By contrast, in infants of the dingo there is a complex pattern in which the muzzle is largely dark but there are whitish marks on parts of the lips and chin, aside the rhinarium, and in some cases extending to the distal part of the rostrum. These markings are individually variable but present in most individuals of the standard colour-morph.

As infants grow into juveniles, the pattern loses its pale flecks and becomes indistinctly dark over much of the muzzle (https://www.inaturalist.org/observations/89225693 and https://www.inaturalist.org/observations/81983214 and https://www.inaturalist.org/observations/71663760 and https://www.inaturalist.org/observations/67124636).

Adolescents retain traces of the darkness despite reaching sexual maturity at one to two years old (https://www.inaturalist.org/observations/93544162), and it is only in full maturity (older than four years) that all traces of the dark are replaced by whitish.

There are a few domestic breeds which show similar ontogenetic changes, but these are the ones most closely related to the dingo. An example is the Shiba Inu of Japan, which is always kept as a pet but has both the same range of adult colouration as the dingo and some of the same aloof and independent demeanour.

Dingo

https://www.buzzfeed.com/annamendoza/dingo-puppies-cute

https://www.heraldsun.com.au/subscribe/news/1/?sourceCode=HSWEB_WRE170_a_GGL&dest=https%3A%2F%2Fwww.heraldsun.com.au%2Fnews%2Fvictoria%2Fget-up-close-and-cuddle-a-dingo-pup-at-the-dingo-discovery-sanctuary-and-research-centre%2Fnews-story%2F35cf7c8cad171f949432b44939abdbad&memtype=anonymous&mode=premium&v21=dynamic-cold-test-noscore&V21spcbehaviour=append

https://www.mentalfloss.com/article/606734/stray-puppy-australia-endangered-alpine-dingo

https://www.facebook.com/CampsAustraliaWide/photos/a.419224444781063/1596678647035631/

https://phys.org/news/2019-11-lost-pup-rare-purebred-dingo.html

https://www.bigstockphoto.com/image-345400699/stock-photo-australian-dingo-pup

https://www.inaturalist.org/observations/56116470

https://www.abc.net.au/news/2018-07-23/mine-worker-by-dingo-in-pilbara-telfer/10024610

https://www.inaturalist.org/observations/64421737

https://www.alamy.com/close-up-shot-showing-face-of-dingo-in-the-wild-at-australian-outback-image62175652.html

Canis familiaris

https://www.facebook.com/kansaslabrador.puppies/

https://www.wedoadz.com/listing/labrador-puppies/

https://pixers.hk/posters/two-german-shepherd-puppies-58843926

https://www.abc.net.au/news/2019-08-24/canberra-women-bringing-german-shepherds-back/11438902

Canis latrans

https://naturallycuriouswithmaryholland.wordpress.com/2019/06/03/eastern-coyote-pups-exploring/

https://www.dglobe.com/community/people/7142564-Wildlife-inspires-Worthington-man-to-catch-critters-on-camera

https://www.focus-on-nature.com/Mammals/Coyotes-and-Wolves/i-jJdx6xZ/A

https://www.flickr.com/photos/nature80020/17700778881

https://commons.wikimedia.org/wiki/File:Gpa_bill_coyote_pup_2.jpg

https://upload.wikimedia.org/wikipedia/commons/d/da/Gpa_bill_coyote_pup.jpg

https://www.shutterstock.com/image-photo/close-coyote-pup-baby-canis-latrans-1329108245

Shiba Inu breed

https://www.istockphoto.com/photo/puppy-shiba-inu-gm543334564-97468005

https://www.istockphoto.com/photo/puppies-shiba-inu-gm584227066-100018789

https://www.facebook.com/Pac-Shiba-Inu-Puppies-104730361492142/

https://pixers.uk/stickers/shiba-inu-puppies-65995359#configurator

Carolina dog breed

http://www.californiacarolinadogs.com/how-to-buy-puppy.htm

Anotado en domingo, 19 de septiembre de 2021 a las 10:44 AM por milewski milewski | 0 comentarios | Deja un comentario

18 de septiembre de 2021

The domensal dog that is the dingo

Europeans first exploring Australia were surprised by more than the hopping of kangaroos.

They found that the largest non-human predator on this continent-size island is was a canid merely the size of a coyote (Canis latrans) or a terrier.

This means that the dingo was uniquely small for the largest carnivore in a continental fauna.

Even more surprisingly, they later found that the dingo - far from emulating kangaroos in being unique to Australia - is shared with Thailand (https://www.dreamstime.com/stock-photos-native-thai-dog-image21021823 and https://www.flickr.com/photos/markborinelli/8340679212), Borneo (https://www.researchgate.net/figure/North-Borneo-dog-Niah-Sarawak-Malaysia-2012_fig3_297893383), Sulawesi, New Guinea and other peninsular/insular parts of southeast Asia and Indonesia (e.g. see https://news.griffith.edu.au/2016/03/24/archaeologists-find-key-to-dingo-mystery/).

The dingo seems to have been brought to Australia only 5,000 years ago, despite the human species having arrived 60,000 years ago and the dog having been domesticated in Eurasia 15,000 years ago.

Adding to the puzzle, the dingo differs from both the wolf (Canis lupus) and the domestic dog (Canis familiaris) without being intermediate between them (https://www.taxonomyaustralia.org.au/post/the-trouble-with-dingoes). For example, the dingo shows colour-polymorphism including a black-and-tan morph (https://www.deviantart.com/silenceangel/art/Black-and-Tan-Dingo-43694277 and https://vks737.radio/project/black-dingo-anne-beadell-highway-wa/) never recorded in the wolf.

Most significantly, the dingo cannot satisfactorily be described as domestic, or feral, or wild.

How can we integrate these surprises into a coherent interpretation of the true nature of the dingo?

Perhaps a key is to recognise a new category, which in my latest Post I have called 'domensal'.

The aboriginal people of Australia, in general, neither kept the dingo captive, nor controlled its reproduction, nor used it to perform services such as hunting. Even after being hand-reared, the dingo remains disobedient. It refuses to take orders from even those human individuals whom it treats as kin and to whom it is loyal.

Instead, the essential relationship was as follows.

The dingo was attracted to human camps mainly for edible refuse and consumable human faeces. The people sometimes transferred infants (https://www.youtube.com/watch?v=2ZB_1ZfWmhQ and https://www.portstephensexaminer.com.au/story/7332302/pups-join-oakvale-dingo-pack-photos/ and https://www.mentalfloss.com/article/606734/stray-puppy-australia-endangered-alpine-dingo) from dens to their camps, hand-rearing them as children's pets.

Once adult, the dingo was free to leave human company in order to breed with mates of its own choice like a wild animal.

This means that, in its own way, the dingo paralleled my description of the Maasai donkey (in my latest Post, of September 17, 2021).

The equid carried burdens in return for the benefit of protection from wild predators in corrals devoted to domestic ruminants.

By comparison, the canid afforded a supply of pets in return for the benefit of using food-waste at human camps.

Perhaps as a result of the relaxation of selective breeding by humans, the dingo parallels the Maasai donkey in having wild-type colouration. In both cases, remarkably few individuals have the irregular and asymmetrical features of colouration typical of domestic species (https://newsroom.unsw.edu.au/news/science-tech/dogs-not-gone-wild-dna-tests-show-most-wild-dogs-australia-are-pure-dingoes).

Both the Maasai donkey and the dingo have small bodies, which means that their demands on resources are limited. Throughout its range except for the seasonally cold southeast of Australia, the dingo has average adult body mass of only 10-15 kg, compared to 20-30 kg for the wolf in similar climates.

The dingo has for several thousand years been the only non-human predator capable of hunting adult kangaroos, and has large jaws for its body size. However, it has not compensated in body size to emulate the wolf, instead remaining more similar to a jackal.

The recent arrival of the dingo in Australia (and, probably, New Guinea) is consistent with its ecological niche not being unique to Australia. Across a wide spectrum of island-like situations, the local people have not, for various cultural reasons, considered canids to have utilitarian value. The result is that in Asia/Indonesia the dingo is essentially a street-dog, owned by nobody but in the long term tolerated in certain villages.

Does all of this add up to the following characterisation?

The dingo is the canid most adapted to a domensal niche, which it has managed to occupy over a wide range of climates, human population densities, and human economic systems. Like the Maasai donkey, the dingo is domesticated enough to be non-threatening to humans, and useful enough to be tolerated, but maintains the ambivalent relationship mainly for certain benefits afforded passively by the humans.

Anotado en sábado, 18 de septiembre de 2021 a las 05:59 AM por milewski milewski | 4 comentarios | Deja un comentario

17 de septiembre de 2021

The Maasai donkey as a domensal animal

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 (e.g. https://www.alamy.com/stock-photo-pair-of-nubian-donkeys-rubbing-necks-144129111.html), are no longer selectively bred, and remain cooperative with humans on a part-time basis?

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

An example is the Maasai 'breed' of the donkey (Equus asinus, file:///C:/Users/Antoni%20Milewski/Downloads/A2-18-2012-Ylmazetal-DomesticatedDonkeys-PartII-TypesandBreeds.pdf and https://www.researchgate.net/profile/Lior-Weissbrod/publication/231225965_The_consequences_of_women's_use_of_donkeys_for_pastoral_flexibility_Maasai_ethnoarchaeology/links/0fcfd50668ffa4070b000000/The-consequences-of-womens-use-of-donkeys-for-pastoral-flexibility-Maasai-ethnoarchaeology.pdf).

The Maasai donkey is small (average adult female body mass probably about 110 kg, https://www.alamy.com/masai-woman-in-colourful-costume-with-donkey-in-a-tribal-community-image4809896.html and https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7585663/) compared to the Somali wild ass (Equus africanus somaliensis, about 250 kg) and inhabits East African pastoral areas in southern Kenya and northern Tanzania. It has the appeal, to naturalists, of a quasi-wild animal; given that no wild ancestor survives (at least in pure form), it is as close as we can get today to a lost member of the original fauna of North Africa.

Pastoralists in East Africa have allowed the donkey to revert to a semi-feral state in ecosystems in which the equid niche is already occupied by the plains zebra (Equus quagga boehmi). By remaining in the vicinity of the encampments, the Maasai donkey avoids competition with its wild relative. Although it is amenable to carrying human baggage (mainly water) in the dry season for a few hours every few days, it goes its own way during the two rainy seasons each year (see https://discover.hubpages.com/animals/The-Donkey-Meetings-of-Ole-Tepesi). Overall, the Maasai make few attempts to herd, feed, control, or protect it.

The Maasai donkey spontaneously gravitates to the corrals in the evenings, to share safety from predators with the domestic bost (Bos taurus/indicus, https://www.alamy.com/stock-photo-young-masai-boy-watching-village-cattle-in-the-masai-mara-kenya-25449359.html), the domestic sheep (Ovis aries, https://www.alamy.com/stock-photo-maasai-tribe-in-kenyafarming-farm-agriculture-goat-goats-sheep-animal-51092287.html and https://www.alamy.com/maasai-boy-shepherd-with-flock-of-sheeps-and-ol-doinyo-lengai-on-background-maasailand-engare-sero-natron-lake-coast-rift-valley-image342341072.html) and the domestic goat (Capra hircus, https://www.alamy.com/same-tanzania-4th-june-2019-maasai-man-herding-his-goats-image255881864.html and https://www.alamy.com/stock-photo-maasai-tribe-in-kenyafarming-farm-agriculture-goat-goats-sheep-animal-51088506.html). In doing so of its own accord, it behaves like a commensal rather than a domestic animal.

The Maasai donkey is not utilised by the pastoralists for food (either flesh or milk). Indeed it is taboo to eat this species, the sole value of which is as an intermittent beast of burden. Individuals of the Maasai donkey are owned by individual Maasai women, but no net production is expected in the population because the slow breeding of the donkey, subject to mortality in line with wild rather than domestic species, produces no surplus. The donkey tends not to be traded, because this would gain little profit; the Maasai regard the donkey as neither an investment nor a status-symbol.

The Maasai hardly try to control the reproduction of the donkey, apart from the castration of particularly unruly males. Selective breeding, a criterion for domestication, has been relaxed.

It could be argued that the Maasai donkey, in retaining the reduced brain and relatively short legs of its species, remains a domestic animal because of its previous history of selective breeding.

However, its colouration shows minimal individual variation or domestic influence (e.g. see https://www.inaturalist.org/observations/10062352 and https://www.alamy.com/masai-donkeys-at-a-waterpoint-lake-magadi-kenya-image151851706.html), conforming to a wild pattern and lacking the irregular and asymmetrical features so valued by the Maasai in their breeds of bost, sheep and goat. We do not know whether this is a case of 'feral reversion' to the wild-type colouration, or an uninterrupted inheritance of the original colouration of the ancestral species of wild ass.

So, given the above context, which of the following two ways to think of the Maasai donkey is more appropriate?

One is that here we have a wild animal which has been modified mainly by reducing its intelligence and body size to the point that it can be handled by women, without otherwise altering its natural biology in terms of adaptive colouration, foraging ecology, or reproductive behaviour.

Another is that the essential relationship is that the Maasai exploit the donkey for carrying heavy burdens, in return for which the donkey exploits the Maasai for protection from wild predators.

Either way, would it not perhaps be appropriate to include this domensal form of donkey in field guide-books to the mammalian fauna of East Africa?

https://www.pond5.com/stock-footage/item/83623359-two-donkeys-eating-red-sandy-soil-food-arid-african-desert

https://www.alamy.com/masai-woman-coming-to-drink-his-donkeys-lake-magadi-kenya-image151778090.html

https://www.dreamstime.com/maasai-girl-hauling-water-buckets-her-donkey-back-to-home-village-dirt-road-natron-tanzania-africa-image138849619

https://www.alamy.com/stock-photo-a-maasai-boy-brings-water-home-from-a-well-kilimanjaro-region-tanzania-27263140.html

https://www.alamy.com/stock-photo-maasai-herdsman-herding-donkeys-equus-asinus-in-tanzania-east-africa-26343630.html

https://www.alamy.com/stock-photo-datoga-man-herding-donkeys-lake-eyasi-northern-tanzania-175256082.html

https://www.osiligilaimaasailodge.co.tz/activities/view/donkey-ride-with-the-maasai

https://i1.wp.com/borderjumpers.net/wp-content/uploads/2015/09/serengeti-11.jpg

https://www.istockphoto.com/photo/young-maasai-woman-with-donkeys-in-village-gm525772713-52928944

https://www.dreamstime.com/stock-photo-oldonyo-masai-village-donkeys-tanzania-image75190971

https://www.flickr.com/photos/jaygalvin/48878024206/in/photostream/

https://www.flickr.com/photos/jaygalvin/48878218297/in/photostream/

Anotado en viernes, 17 de septiembre de 2021 a las 04:51 AM por milewski milewski | 9 comentarios | Deja un comentario

16 de septiembre de 2021

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

Everyone knows that the donkey (Equus asinus) has large ear pinnae (https://www.dreamstime.com/beautiful-healthy-young-donkey-head-shot-closeup-outdoors-nature-under-blue-sky-summertime-image177482516 and https://www.dreamstime.com/royalty-free-stock-photo-portrait-donkey-young-image33561705 and https://www.dreamstime.com/closeup-shot-donkey-s-ears-image162450034).

Some may also know that the posterior surface of the ear pinna has a clear pattern in many individuals with otherwise relatively plain colouration (https://www.dreamstime.com/donkey-green-background-donkey-image104711551 and https://www.dreamstime.com/stock-photo-gray-donkey-stall-photo-image57329235 and https://www.dreamstime.com/donkey-farm-closeup-details-osio-sopra-lombardy-italy-image207081626 and https://www.dreamstime.com/stock-photo-donkey-face-green-summer-pasture-ears-back-image42747898 and https://www.dreamstime.com/close-up-donkey-ears-zoo-mammal-animal-image193227750 and https://www.dreamstime.com/stock-photo-donkey-jackass-gray-animal-mammal-green-field-pasture-meadow-country-farm-image96520464 and https://www.dreamstime.com/stock-photo-donkey-cage-farm-image82243350 and https://www.dreamstime.com/portrait-cute-baby-donkey-brown-ears-grey-fur-long-image122599750 and https://www.dreamstime.com/stock-photo-portrait-donkey-green-field-image50275360 and https://www.dreamstime.com/stock-photo-grazing-donkey-rural-grassland-spring-image49315026 and https://www.dreamstime.com/stock-photo-two-brown-donkeys-face-to-face-head-touching-head-seems-to-show-love-affection-thailand-image70709424 and https://www.dreamstime.com/donkey-outdoors-nature-under-blue-sky-summertime-beautiful-healthy-young-donkey-head-shot-closeup-image177481641).

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 https://www.dreamstime.com/stock-photo-mother-baby-donkey-touching-image56673141 and https://www.dreamstime.com/royalty-free-stock-images-donkey-farm-looking-to-camera-image35894929).

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 https://www.dreamstime.com/head-view-grey-donkey-colorful-leaves-ground-head-view-grey-donkey-colorful-leaves-ground-image122994822 and https://www.dreamstime.com/stock-image-donkey-foal-sweet-resting-green-grass-image37424141 and https://www.dreamstime.com/stock-photo-donkey-paddock-grey-image77428659).

The following compare Equus hartmannae with the donkey:

https://www.dreamstime.com/royalty-free-stock-photography-grazing-zebra-image10344857 and https://www.dreamstime.com/hartmann-s-mountain-zebra-close-up-picture-image120447528 and https://www.dreamstime.com/stock-photo-zebra-close-up-balck-white-image57223001 vs https://www.dreamstime.com/vertical-shot-donkey-outdoors-daylight-image213996791 and https://www.dreamstime.com/gray-donkey-farm-domestic-image122639149

https://www.dreamstime.com/zebra-head-close-up-rear-top-view-zebra-close-up-zebra-head-zoo-wild-image197451943 vs https://www.dreamstime.com/head-grey-donkey-side-view-inside-barn-head-grey-donkey-side-view-inside-barn-zoo-image122994594 and https://www.dreamstime.com/royalty-free-stock-images-donkey-head-shot-image29428039

The following compare Equus grevyi with the donkey:

https://www.gettyimages.com.au/detail/photo/kenya-samburu-grevys-zebra-portrait-royalty-free-image/91515202?adppopup=true and https://www.dreamstime.com/stock-photo-zebra-grevy-s-close-up-thorn-tree-image52490044 and https://www.gettyimages.com.au/detail/photo/zebra-head-shot-royalty-free-image/1266843816?adppopup=true and https://www.dreamstime.com/close-up-imperial-zebra-as-rests-green-grass-zebra-head-shot-image193753856 and https://www.gettyimages.com.au/detail/photo/close-up-of-zebra-on-field-royalty-free-image/1330973893?adppopup=true and https://www.dreamstime.com/black-white-zebra-portrait-close-up-blurred-background-portrait-zebra-hippotigris-close-up-image151442462 and https://www.dreamstime.com/stock-photography-zebra-fom-front-image7527262 vs https://www.dreamstime.com/stock-photo-little-girl-feeding-donkey-image75810712 and https://www.dreamstime.com/friendly-brown-young-donkey-outdoors-friendly-brown-young-donkey-outdoors-farm-image131172806 and https://www.dreamstime.com/span-tethered-donkey-near-alora-malaga-province-andalucia-spain-europe-image175706513

The following compare Equus quagga boehmi with the donkey:

https://www.dreamstime.com/zebra-close-up-various-blurry-zebras-background-image150063111 and https://www.dreamstime.com/zebra-close-up-various-blurry-zebras-background-image150062978 vs https://www.dreamstime.com/donkey-face-closeup-farm-portrait-image148765680 and https://www.dreamstime.com/donkey-public-park-autumn-season-image129548516 and https://www.dreamstime.com/beautiful-brown-young-donkey-outdoors-farm-image131173076

The following compare Equus quagga chapmani with the donkey:

https://www.dreamstime.com/zebras-funny-hairstyle-ears-close-up-back-view-zebras-funny-hairstyle-ears-close-up-striped-animals-look-distance-back-image225542588 vs https://www.dreamstime.com/beautiful-ears-back-donkey-head-close-up-withers-image229151249

https://www.dreamstime.com/royalty-free-stock-images-zebra-image7304859 vs https://www.dreamstime.com/stock-photo-young-donkey-looks-to-camera-image68488110 and https://www.dreamstime.com/stock-photo-brown-gray-donkey-walks-paddock-outdoors-image50649391 and https://www.dreamstime.com/donkey-public-park-autumn-season-image129548205

The following compare the Somali wild ass (Equus africanus somaliensis) with the donkey:

https://www.dreamstime.com/sleepy-little-wild-burro-resting-gravel-old-western-town-oatman-arizona-cutie-pie-wildlife-donkeys-wild-burros-image199715189 vs https://www.dreamstime.com/donkey-foal-lying-sand-donkey-foal-lying-sand-little-horse-baby-image116826914.

https://www.shutterstock.com/nb/image-photo/somali-wild-ass-mother-her-foal-150267275

https://www.dreamstime.com/stock-image-somali-wild-ass-image26192561

https://www.dreamstime.com/somalian-wild-donkey-equus-asinus-somalicus-nature-portrait-somalian-wild-donkey-equus-asinus-somalicus-nature-image151236252

https://www.dreamstime.com/somalian-wild-donkey-equus-asinus-somalicus-eating-grass-nature-portrait-image151236779

Anotado en jueves, 16 de septiembre de 2021 a las 01:22 AM por milewski milewski | 7 comentarios | Deja un comentario