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 donkey breeds slowly and is subject to mortality in line with a wild species. The donkey tends not to be traded, because this produces negligible profit; the Maasai do not regard the donkey as either an investment or 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.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/

Ingresado el 17 de septiembre de 2021 por milewski milewski | 1 comentario | 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

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

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.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

Ingresado el 16 de septiembre de 2021 por milewski milewski | 4 comentarios | Deja un comentario

15 de septiembre de 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)? https://www.pt63.co.uk/pics/013053891-indian-deer

Nothing in particular?

Try again. How about this view of the western grey kangaroo (Macropus fuliginosus)? https://www.art.com/products/p13472210-sa-i2683988/thorsten-milse-kangaroo-island-kangaroo-macropus-fuliginosus-flinders-chase-n-p-south-australia-australia.htm?upi=P2RJ5Q0&PODConfigID=4990619&sOrigID=27402

Still unsure what I'm referring to?

Surely this view of the dhole (Count alpinus) gives a hint too big to miss? https://faunafocus.com/2018/03/28/dhole-28/

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 https://fpnotebook.com/_media/ent_earExternal.png and https://www.istockphoto.com/vector/anatomy-of-the-human-ear-vector-illustration-gm1244877377-363009612 and https://www.vecteezy.com/vector-art/471104-human-ear-structure-medical-background-poster and https://elementsofmorphology.nih.gov/anatomy-ear.shtml and http://www.visualdictionaryonline.com/human-being/sense-organs/hearing/pinna.php and https://www.pinterest.com.au/pin/443463894542150161/ and https://www.researchgate.net/figure/Anatomical-landmarks-of-Human-Ear_fig1_236462167).

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 (https://www.gettyimages.com.au/detail/photo/portrait-of-a-wallaroo-australia-royalty-free-image/1291570919?adppopup=true) and Osphranter antilopinus (https://www.gettyimages.com.au/detail/news-photo/antilopine-wallaroo-queensland-australia-news-photo/72414285?adppopup=true).

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

Cuon alpinus

https://www.jungledragon.com/image/61605/dhole_-_adult_portrait_zie-zoo_netherlands.html/zoom
https://www.shutterstock.com/image-photo/closeup-dhole-582778501
https://www.flickr.com/photos/coastermadmatt/37530331026/

Lycaon pictus

https://www.agefotostock.com/age/en/details-photo/african-wild-dog-lycaon-pictus-pup-close-up-of-head-kwando-lagoon-linyanti-botswana/FHR-10354-00384-833

Chrysocyon brachyurus

https://news.mongabay.com/2015/12/the-maned-wolf-saving-south-americas-unfortunately-named-canid/
https://animal-groups-roleplay.fandom.com/wiki/User_blog:Ashesandcinders/Theta_Page_Coding

Felis lybica griselda

https://www.alamy.com/stock-photo-wild-face-portrait-eyes-ears-african-pussycat-cat-domestic-cat-desert-142761328.html

Leptailurus serval

https://www.earth.com/earthpedia-articles/savannah-cats-vs-servals-theyre-not-the-same/

Bubalus carabanensis

https://www.shutterstock.com/nb/image-photo/close-one-ear-buffalo-1980266327

Syncerus nanus

https://stock.adobe.com/sk/search/images?k=%22congo+buffalo%22&asset_id=264529775
https://www.wikiwand.com/en/African_forest_buffalo

Tragelaphus eurycerus

https://www.startribune.com/minnesota-zoo-visitors-can-size-up-newborn-bongo-antelopes/212963491/

Strepsiceros strepsiceros

https://www.flickr.com/photos/charissadescandelotter/37180972132/
https://focusedcollection.com/203451630/stock-photo-portrait-female-greater-kudu-kalahari.html
https://unsplash.com/photos/QVbv-gsswtE

Rusa unicolor

https://www.planetstillalive.com/asia/india/india-sambars/#prettyPhoto[gal]/1/
https://www.planetstillalive.com/asia/india/india-sambars/#prettyPhoto[gal]/8/

Ingresado el 15 de septiembre de 2021 por milewski milewski | 2 comentarios | Deja un comentario

14 de septiembre de 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 https://scienceillustrated.com.au/blog/nature/ask-us-what-gives-bird-feathers-their-colours/#:~:text=Pigments%20called%20melanins%2C%20carotenoids%20and,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 (https://en.wikipedia.org/wiki/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 (https://animals.mom.com/changes-in-the-color-of-a-roosters-comb-12624586.html and https://www.yourchickens.co.uk/care-and-advice/skin-and-feathers-1-1013807 and https://chickens.fandom.com/wiki/Earlobes). 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 (https://www.alamy.com/stock-photo-ostrich-struthio-camelus-camelus-red-necked-subspecies-143922867.html and https://www.alamy.com/stock-photo-ostrich-male-red-neck-during-mating-season-55967022.html and https://twitter.com/brglilly/status/598563930877878272). 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 (https://www.britannica.com/story/why-are-flamingos-pink).

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?
https://www.dreamstime.com/stock-photo-eye-deer-persian-fallow-dama-mesopotamica-ear-image81204749.

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: https://www.dreamstime.com/full-body-portrait-african-hare-lepus-capensis-backlit-large-ears-eating-leaf-sitting-grass-next-to-dirt-road-image131453041. However, in the following the hue has intensified to reddish: https://upload.wikimedia.org/wikipedia/commons/4/44/Lepus_europaeus_%28Causse_M%C3%A9jean%2C_Loz%C3%A8re%29-cropped.jpg. The following are not necessarily bloodshot but clearly show the blood vessels: https://i.redd.it/7jyb9cu0s5r61.jpg and https://www.jungledragon.com/image/69607/black-tailed_jackrabbit.html.

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

https://windling.typepad.com/.a/6a00e54fcf73858834017ee3ca2116970d-pi
https://www.dreamstime.com/stock-photo-young-mule-deer-buck-listens-carefully-large-ears-predators-image92730853
https://www.dreamstime.com/eyes-have-mule-deer-colorado-aspen-grove-doe-froze-seconds-july-pm-natural-beauty-curiousn-intrigued-image161491889

Strepsiceros strepsiceros

https://www.dreamstime.com/royalty-free-stock-photos-female-kudu-antelope-image16919768
https://www.dreamstime.com/stock-image-kudu-antelope-female-image22113571
https://www.dreamstime.com/stock-photo-close-up-female-kudu-looking-directly-ahead-isolated-large-ears-image63183597
https://www.agefotostock.com/age/en/details-photo/kudu-antelope-ears/ESY-012245060
https://elements.envato.com/greater-kudu-cow-looking-forward-with-pointed-ears-75HYTFX
https://www.alamy.com/stock-photo-portrait-of-a-kudu-antelope-tragelaphus-strepsiceros-kruger-national-36406290.html
https://www.facebook.com/thesavetheearthfoundation/photos/beautiful-kudu-antelope/10156804168193883/
https://www.dreamstime.com/royalty-free-stock-photo-kudu-doe-portrait-image23041455
https://www.dreamstime.com/royalty-free-stock-photography-portrait-female-kudu-southern-africa-image12102547

Ammelaphus imberbis

https://www.dreamstime.com/stock-photo-female-lesser-kudu-wild-tragelaphus-imberbis-hiding-shade-acacia-tree-tsavo-east-national-game-park-kenya-slim-image85101068

Syncerus caffer

(for comparison, in the following there is a bleeding injury on the ear pinna: https://www.dreamstime.com/royalty-free-stock-photography-male-cape-buffalo-synceros-caffer-south-africa-s-mala-mala-game-reserve-image37431597)

https://www.dreamstime.com/royalty-free-stock-image-cape-buffalo-standing-looking-image29646066
https://www.dreamstime.com/stock-photo-cape-buffalo-feeding-lily-pads-choebe-river-image85656649
https://www.dreamstime.com/stock-photo-african-cape-buffalo-portrait-large-curved-horns-beady-eyes-image75599885
https://www.dreamstime.com/cape-buffalo-facing-camera-sunlit-savannah-cape-buffalo-facing-camera-sunlit-savannah-image158242664
https://www.dreamstime.com/stock-image-cape-buffalo-image3988891
https://www.istockphoto.com/photo/cape-buffalo-with-beautiful-ears-gm948580952-258972570
https://www.dreamstime.com/royalty-free-stock-photo-cape-buffalo-image9337875
https://www.dreamstime.com/stock-photos-cape-buffalo-bull-image12757143
https://www.dreamstime.com/stock-images-cape-buffalo-syncerus-caffer-image3673374
https://www.alamy.com/stock-photo-close-up-of-cape-buffalo-greater-kruger-national-park-south-africa-17107256.html
https://www.dreamstime.com/stock-photo-cape-buffalo-portrait-grazing-grass-s-mouth-image72100055

Bos indicus

https://www.istockphoto.com/photo/pretty-little-calf-standing-alone-in-a-stall-gm467528694-60384158
https://www.alamy.com/stock-photo-young-calf-with-big-floppy-ears-seen-in-the-town-of-guane-colombia-126933243.html
https://www.alamy.com/stock-photo-zebu-cattle-10830070.html
http://jeffshea.org/photos/thailand-loei-prov-long-eared-cow-2008-img-6452/

Ingresado el 14 de septiembre de 2021 por milewski milewski | 4 comentarios | Deja un comentario

13 de septiembre de 2021

Discovering an auricular semet in a kangaroo

Macropods (https://en.wikipedia.org/wiki/Macropodidae) vary greatly in the colouration of their ear pinnae, from plain (https://www.dreamstime.com/close-up-face-australian-kangaroo-australian-kangaroo-close-up-image110723140 and https://www.alamy.com/australia-western-australia-rottnest-island-close-up-of-quokka-setonix-brachyurus-image407731469.html and https://www.megapixl.com/quokka-with-baby-stock-photo-87442) to patterned (https://www.dreamstime.com/western-grey-kangaroo-macropus-fuliginosus-grazing-hiding-grass-deep-creek-south-australia-western-grey-kangaroo-macropus-image216721185 and https://fineartamerica.com/featured/western-grey-kangaroo-1600-stephen-reid.html and https://en.wikipedia.org/wiki/Western_grey_kangaroo#/media/File:Grey_Roo_with_Joey_SMC_2006.jpg).

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 https://www.twenty20.com/photos/ig-272766529165172542_10102) are whitish, and noticeable at close quarters. However, at some distance the species vary between earlashes which could plausibly function as camouflage (https://www.dreamstime.com/eastern-grey-kangaroo-brisbane-queensland-australia-kangaroo-let-me-get-quite-close-didn-t-seem-too-bothered-me-just-kept-image124674030) and those which, by virtue of dark emphasis, could plausibly function as an auricular semet (https://www.dreamstime.com/stock-photo-western-grey-kangaroo-close-up-mountainside-along-backstairs-passage-deep-creek-conservation-park-fleurieu-image84117707).

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 (http://www.arthurgrosset.com/mammals/photos/macful41897.jpg and https://www.alamy.com/stock-photo-a-close-up-shot-of-the-head-and-shoulders-of-a-kangaroo-58978456.html).

Of the five species, only the western grey kangaroo (Macropus fuliginosus, https://en.wikipedia.org/wiki/Western_grey_kangaroo) 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: https://www.dreamstime.com/stock-image-kangaroo-image19861361 and https://www.dreamstime.com/western-grey-kangaroo-resting-some-grass-stubble-western-grey-kangaroo-image145350377 and https://www.dreamstime.com/kangaroo-island-kangaroo-eating-hay-kangaroo-island-kangaroo-looking-over-its-shoulder-image175272279 and https://www.dreamstime.com/portrait-young-cute-australian-kangaroo-standing-field-waiting-portrait-young-cute-australian-kangaroo-standing-image139403458 and https://www.dreamstime.com/two-cute-australian-kangaroo-standing-field-waiting-two-cute-australian-kangaroo-standing-field-image139403587 and https://www.dreamstime.com/portrait-young-cute-australian-kangaroo-standing-field-waiting-joey-image139403370.

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

https://www.dreamstime.com/male-kangaroo-portrait-close-up-australian-wildlife-male-kangaroo-portrait-bush-australian-marsupial-wildlife-image215924572
https://www.istockphoto.com/photo/kangaroo-close-up-gm94025073-11210235
https://www.canstockphoto.com/kangaroo-up-close-0739304.html
https://es.123rf.com/photo_1150862_kangaroo-close-up.html
https://www.dreamstime.com/joey-young-kangaroo-portrait-close-up-australian-wildlife-joey-young-kangaroo-portrait-australian-marsupial-wildlife-image215925302
https://www.twenty20.com/photos/5777479a-229e-4496-9e09-73419962bee3
https://www.dreamstime.com/close-up-australian-kangaroo-against-background-sand-beach-sunrise-close-up-australian-kangaroo-image117548937
https://www.dreamstime.com/stock-photo-kangaroo-resting-up-grasslands-australian-outback-young-kangaroo-resting-close-up-australian-wildlife-australia-image81647860
https://www.dreamstime.com/close-up-australian-kangaroo-face-image110723062
https://www.dreamstime.com/royalty-free-stock-photos-beautiful-kangooro-australia-close-up-head-kangaroo-image35226858

Macropus fuliginosus

https://www.dreamstime.com/stock-photo-close-up-young-kangaroo-wildlife-image60746879
https://www.dreamstime.com/stock-photo-kangaroo-lovely-australian-up-close-image54746870
https://www.dreamstime.com/royalty-free-stock-photos-kangaroo-portrait-image2322248
https://www.dreamstime.com/royalty-free-stock-photography-australian-kangaroo-image1783707
https://www.dreamstime.com/portrait-young-cute-australian-kangaroo-big-bright-brown-eyes-looking-close-up-camera-portrait-young-cute-australian-image139051408
https://www.sciencephoto.com/media/384499/view/western-grey-kangaroo
http://www.birdway.com.au/macropodidae/western_grey_kangaroo/source/westerngrey_kangaroo_38550.php
https://www.dreamstime.com/close-uo-kangaroo-island-kangaroo-portrait-kangaroo-island-kangaroo-image175916539
https://www.dreamstime.com/portrait-young-cute-australian-kangaroo-big-bright-brown-eyes-looking-close-up-camera-portrait-young-cute-australian-image139051481
https://www.dreamstime.com/portrait-young-cute-australian-kangaroo-big-bright-brown-eyes-looking-close-up-camera-australia-image139050157
https://www.dreamstime.com/close-up-portrait-western-grey-kangaroo-wild-picture-its-right-side-yanchep-national-park-australia-wa-image193425978
https://www.dreamstime.com/close-up-powerful-kangaroo-top-half-image140481299
https://www.dreamstime.com/close-up-kangaroo-island-kangaroo-kangaroo-island-kangaroo-image100099307
https://www.dreamstime.com/western-grey-kangaroo-standing-its-hind-legs-male-image182903078
https://www.dreamstime.com/western-grey-kangaroo-macropus-fuliginosus-melanops-mainland-western-grey-kangaroo-macropus-fuliginosus-melanops-also-known-as-image103309237
https://www.dreamstime.com/kangaroo-island-joey-begging-food-image100099317
https://www.dreamstime.com/kangaroo-marsupial-family-macropodidae-macropods-meaning-large-foot-western-gray-eating-hand-image107071113

Osphranter robustus

https://www.inaturalist.org/observations/65800211
https://www.inaturalist.org/observations/84058357
https://www.inaturalist.org/observations/90517070
https://www.inaturalist.org/observations/66857109
https://www.inaturalist.org/photos/8362359
https://www.inaturalist.org/photos/94936327
https://www.inaturalist.org/observations/91494096
https://www.alamy.com/stock-photo-beautiful-wallaroo-euro-macropus-robustus-among-green-grass-staring-89301398.html
https://www.dreamstime.com/stock-photo-kangaroo-australia-outback-image65764183
https://www.alamy.com/stock-photo-beautiful-wallaroo-euro-macropus-robustus-among-green-shrubs-turning-89301412.html
https://www.flickr.com/photos/graham_by_the_sea/3677337194/
https://www.agefotostock.com/age/en/details-photo/common-wallaroo-or-euro-macropus-robustus-male-western-australia/AAM-AAES01506
https://www.naturepl.com/stock-photo-euro-common-wallaroo-macropus-robustus-grazing-cape-range-national-image01227379.html
https://worldfoto.photoshelter.com/image/I0000j5zxBy9ADEM

Osphranter antilopinus

https://www.inaturalist.org/observations/69094515
https://www.inaturalist.org/observations/67219606
https://www.inaturalist.org/observations/46799796
https://www.inaturalist.org/observations/7702299
https://timgrahamstock.photoshelter.com/image/I0000PSmBntcRkLc
https://www.sciencesource.com/archive/Image/Antilopine-Kangaroo-SS2298700.html
https://www.zoochat.com/community/media/antilopine-wallaroo-macropus-antilopinus.408547/
https://www.naturepl.com/stock-photo-antelopine-wallaroo-macropus-antilopinus-australia-captive-image01477042.html
https://www.gettyimages.co.nz/detail/news-photo/antilopine-kangaroo-antilopine-wallaroo-or-the-antilopine-news-photo/492756579
https://commons.wikimedia.org/wiki/File:Macropus_antilopinus_1.jpg
https://www.flickr.com/photos/centralaustralia/2296280726
http://www.oceanwideimages.com/Large-Image.asp?pID=9839&cID=444&rp=species%252Easp%253Fs%253DMacropus%2Bantilopinus%2526p%253D1
http://www.oceanwideimages.com/Large-Image.asp?pID=15070&cID=444&rp=species%252Easp%253Fs%253DMacropus%2Bantilopinus%2526p%253D1

Osphranter rufus

https://www.dreamstime.com/kangaroo-close-up-face-image113887795
https://theoallofs.photoshelter.com/image/I0000TgnYnvW0ZvY
https://www.alamy.com/stock-photo-red-kangaroo-portrait-18441991.html
https://www.dreamstime.com/royalty-free-stock-photo-cute-portrait-kangaroo-close-up-red-macropus-rufus-image36513575
https://www.dreamstime.com/portrait-australian-kangaroo-big-bright-brown-eyes-looking-close-up-camera-looks-like-boss-australia-image139618268
https://www.dreamstime.com/close-up-red-kangaroo-red-kangaroo-image126276196
https://www.dreamstime.com/stock-photo-close-up-brown-kangaroo-male-australian-sitting-ground-image49390554
https://www.dreamstime.com/kangaroo-green-grass-image157073456
https://www.dreamstime.com/stock-photos-kangaroo-portrait-image1839673
https://www.dreamstime.com/stock-photo-young-kangaroo-joey-portrait-young-kangaroo-joey-up-close-personal-sharp-detail-image92974756

Ingresado el 13 de septiembre de 2021 por milewski milewski | 1 comentario | Deja un comentario

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 (https://dewetswild.com/2014/06/27/common-eland/#jp-carousel-4870 and https://www.dreamstime.com/stock-photography-some-eland-image21533192) which reminded them of the European Alces alces (https://fineartamerica.com/featured/cow-moose-2-alex-mironyuk.html) in its rangy build, trotting gait (https://www.alamy.com/stock-photo-moose-alces-alces-young-bull-with-small-antlers-foraging-in-moorland-136137922.html vs https://www.stuporterphotography.com/index/G0000.l6epIS9fOo/I0000oiE0dXv86_E), 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 (https://www.alamy.com/stock-photo-bull-moose-foraging-on-willow-trees-in-the-toklat-river-valley-in-173192723.html) 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 (https://www.alamy.com/stock-photo-bull-moose-feeding-leafes-of-a-willow-103500947.html).

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 (https://www.alamy.com/large-bull-moose-amongst-the-willows-in-a-boreal-forest-image271990520.html).

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 https://www.inaturalist.org/taxa/593611-Salix-mucronata).

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 (https://www.africaguide.com/country/malawi/nyika_national_park.htm), where the eland remains common in an original, wild population (https://www.alamy.com/a-herd-of-common-eland-taurotragus-oryx-in-the-grasslands-of-the-nyika-plateau-nyika-national-park-in-malawi-image344122819.html). Here the Cape willow grows in a unique outlying population deep within the tropics (https://www.inaturalist.org/observations/44890322).

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. https://www.alamy.com/eland-in-the-cederberg-mountains-image337582150.html and https://es.123rf.com/photo_130063893_eland-in-the-cederberg-mountains.html), Eastern Cape (http://shutterstock.puzzlepix.hu/kep/1680384328) and Mpumalanga, where the eland has been reintroduced (https://www.bizcommunity.com/Article/196/628/206817.html) and the Cape willow grows humbly as part of the natural community of shrubs along streams.

Is capturing the African equivalent of https://www.alamy.com/stock-photo-moose-alces-alces-gigas-cow-eating-willow-salix-sp-just-south-of-denali-43929406.html not a worthy challenge for a new generation of naturalists with a heightened appreciation of the subtle connections among seemingly disparate continents and organisms?

Ingresado el 13 de septiembre de 2021 por milewski milewski | 2 comentarios | Deja un comentario

11 de septiembre de 2021

Finding expression in the face of the chacma baboon

The chacma baboon (Papio ursinus) is the largest (see https://www.dreamstime.com/stock-photo-chacma-baboon-impala-kruger-national-park-specie-papio-ursinus-aepyceros-melampus-image65157078) 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 (https://www.masterfile.com/image/en/841-03674368). However, the usual facial expression of masculine defensiveness and assertion is an exaggerated yawn, showing the pale eyelids (https://jukit.files.wordpress.com/2010/07/chacma-baboon-11.jpg and https://www.dreamstime.com/stock-photo-chacma-baboon-yawning-yawns-usually-sign-aggression-as-opposed-to-him-being-tired-image48699729 and https://www.dreamstime.com/stock-photo-fierce-baboon-image10588900 and https://www.dreamstime.com/male-baboon-yawning-showing-us-his-teeth-male-baboon-yawning-showing-us-his-teeth-chobe-national-park-botswana-africa-image136323170). 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: https://www.dreamstime.com/stock-photo-baboon-fear-grimace-chacma-making-as-signal-submission-image58361083 and https://www.dreamstime.com/stock-photo-baboon-chacma-cape-botswana-s-chobe-national-park-africa-image74668460).

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 (https://www.dreamstime.com/royalty-free-stock-photos-chacma-baboon-image14692968 and https://www.dreamstime.com/portrait-chacma-baboon-monkey-chobe-national-park-botswana-image161947287).

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 https://www.dreamstime.com/chacma-baboon-papio-ursinus-monkey-moremi-okavango-delta-botswana-wild-mammal-nature-habitat-feeding-frui-fruits-gren-image129580375 and https://www.dreamstime.com/detail-face-chacma-baboon-papio-ursinus-cape-brown-background-image174907750 and https://www.dreamstime.com/stock-photos-large-chacma-baboon-walking-sunlight-image25315923 and https://www.dreamstime.com/stock-photography-chacma-baboon-sitting-river-bank-image36685692 and https://www.dreamstime.com/close-up-portrait-adult-baboon-open-eyes-looking-straight-camera-sunset-taken-golden-light-chobe-image178656554).

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: https://www.dreamstime.com/baboon-open-mouth-exposing-canine-teeth-chacma-papio-ursinus-also-known-as-cape-image108192461 and https://www.alamy.com/stock-photo-baboon-with-open-mouth-exposing-canine-teeth-the-chacma-baboon-papio-172432622.html).

The 'neonatal makeup' of the chacma baboon (https://www.dreamstime.com/baboon-monkeys-family-african-wildlife-kruger-national-park-south-africa-baboon-family-cute-little-baby-image201661427 and https://www.dreamstime.com/just-born-cute-young-baby-chacma-babbon-just-born-cute-young-baby-chacma-babbon-kruger-national-park-south-africa-image166023097) 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.

Ingresado el 11 de septiembre de 2021 por milewski milewski | 6 comentarios | Deja un comentario

10 de septiembre de 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 (https://anotefromabroad.files.wordpress.com/2015/01/image1.jpg and https://en.wikipedia.org/wiki/Hluhluwe%E2%80%93Imfolozi_Park).

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.

https://www.agefotostock.com/age/en/details-photo/burchell-s-zebra-zebra-common-zebra-equus-quagga-burchelli-equus-burchelli-grazing-south-africa-hluhluwe-umfolozi-national-park-mpila-camp/BWI-BS313547

https://wetanddustyroads.com/2021/02/04/hluhluwe-imfolozi-park/#jp-carousel-4711

https://www.alamy.com/stock-photo-burchells-zebra-equus-burchellii-zulu-nyala-game-reserve-south-africa-57061920.html

https://www.alamy.com/stock-photo-burchells-zebra-equus-burchellii-zulu-nyala-game-reserve-south-africa-57061716.html

https://www.alamy.com/burchells-zebra-zebra-common-zebra-equus-quagga-burchelli-equus-burchelli-standing-south-africa-hluhluwe-umfolozi-national-park-mpila-camp-image277819973.html

https://www.alamy.com/burchells-zebra-equus-quagga-burchellii-and-nyala-tragelaphus-angasi-umkhuze-game-reserve-south-africa-image338056266.html

https://www.alamy.com/burchells-zebra-equus-quagga-burchellii-and-nyala-tragelaphus-angasi-umkhuze-game-reserve-south-africa-image338056260.html

https://www.flickr.com/photos/piazzi1969/23135925750/

https://www.alamy.com/burchells-zebra-equus-quagga-burchellii-and-nyala-tragelaphus-angasi-umkhuze-game-reserve-south-africa-image338056272.html

https://www.safaribookings.com/hluhluwe/wildlife-photos#photo3

https://www.agefotostock.com/age/en/details-photo/plains-zebra-burchell-equus-quagga-burchelli-young-hluhluwe-umfolozi-nationalpark-hluhluwe-imfolozi-nationalpark-kwazulu-natal-south-africa-africa/JHS-S22579

The following is also of interest: https://www.alamy.com/annals-of-the-south-african-museum-=-annale-van-die-suid-afrikaanse-museum-natural-history-fig-9-stripe-patterns-and-tone-of-basic-colours-of-various-plains-zebras-shown-in-standardized-outline-a-female-quagga-at-mainz-museum-b-burchells-zebra-from-zululand-same-as-fig-7b-c-male-burchells-zebra-at-leiden-museum-d-burchells-zebra-from-zululand-same-as-fig-7d-e-quagga-at-tring-museum-near-london-f-type-of-true-burchells-zebra-british-museum-natural-history-destroyed-g-quagga-at-berlin-museum-h-male-quagga-at-mainz-museum-i-burchells-zebra-at-mainz-museu-image236441254.html

Ingresado el 10 de septiembre de 2021 por milewski milewski | 1 comentario | Deja un comentario

09 de septiembre de 2021

An unexpected convergence in colouration between giraffes and zebras

What do you notice about these two photos? https://www.dreamstime.com/stock-photo-sideview-single-giraffe-walking-away-grass-blue-cloudy-sky-background-masai-mara-national-reserve-kenya-image82830656 and https://www.inaturalist.org/observations/40703895.

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: https://www.gettyimages.com.au/detail/photo/lake-manyara-royalty-free-image/993592666?adppopup=true.

However, in all giraffes the back-of-ear is exempt from spotting: https://www.gettyimages.com.au/detail/photo/rear-view-of-giraffe-royalty-free-image/938213700?adppopup=true and https://www.gettyimages.com.au/detail/photo/back-view-of-giraffes-head-royalty-free-image/978650188?adppopup=true.

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: https://www.shutterstock.com/nb/image-photo/back-giraffes-head-660211138 and https://www.gettyimages.com.au/detail/photo/the-view-from-the-top-royalty-free-image/606243456?adppopup=true and https://www.gettyimages.com.au/detail/photo/two-giraffes-watching-the-masai-mara-royalty-free-image/862021714?adppopup=true.

The following show how conspicuous the auricular flag of giraffes can be even at considerable distance:
https://www.stevebloom.com/index.php?page=single&id=500135-BS1 and https://www.gettyimages.com.au/detail/photo/masai-giraffes-giraffa-camelopardalis-with-young-royalty-free-image/501894195?adppopup=true and https://www.gettyimages.com.au/detail/photo/rear-view-of-giraffe-standing-on-field-royalty-free-image/1306755220?adppopup=true and https://www.gettyimages.com.au/detail/photo/two-rothshilds-giraffes-watching-plains-royalty-free-image/179556570?adppopup=true and https://www.gettyimages.com.au/detail/photo/back-shot-of-a-small-group-of-giraffes-that-are-royalty-free-image/1012754850?adppopup=true.

Turning to zebras:

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

Equus grevyi: https://www.alamy.com/the-rear-end-of-a-zebra-image67915237.html and https://www.shutterstock.com/nb/image-photo/funny-hairstyle-45337102 and https://www.shutterstock.com/nb/image-photo/grevy-zebra-lies-on-back-dust-1392261350 and https://www.alamy.com/young-grvys-zebra-equus-grevyi-captive-germany-image345691452.html

(the following nicely compare the front- and back-of-ear of E. grevyi: https://www.gettyimages.com.au/detail/photo/grevys-zebra-shaba-national-reserve-royalty-free-image/10183209?adppopup=true vs https://www.gettyimages.com.au/detail/photo/zebra-staring-at-camera-kenya-royalty-free-image/974550158?adppopup=true)

Equus hartmannae: https://www.maxpixel.net/Zebra-Stripes-Hartmanns-Africa-Mountain-Zebra-3936198 and https://www.gettyimages.com.au/detail/news-photo/newborn-hartmanns-mountain-zebra-is-pictured-in-the-zoo-of-news-photo/186455823?adppopup=true

Equus zebra: https://www.safaribookings.com/mountain-zebra-np/photos#photo22 and https://www.news24.com/news24/video/southafrica/news/watch-the-battle-for-the-cape-mountain-zebras-future-20180514

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 https://www.alamy.com/stock-photo-rear-view-of-plains-zebra-equus-quagga-tala-game-reserve-kwazulu-natal-27582605.html and https://www.gettyimages.com.au/detail/photo/plains-zebra-or-burchells-zebra-equus-quagga-royalty-free-image/487706871?adppopup=true).

The basic pattern in this species, which varies according to subspecies and individual, is https://www.shutterstock.com/nb/image-photo/zebras-funny-hairstyle-ears-close-back-2015084141. 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 (https://www.zoochat.com/community/media/maneless-zebra.258938/ and https://www.alamy.com/stock-photo-maneless-zebra-122564227.html and https://www.flickr.com/photos/ianpressphotography/48086484923 and https://www.alamy.com/stock-photo-maneless-zebra-122564225.html and https://www.flickr.com/photos/7332125@N04/14187485413 and https://www.inaturalist.org/observations/69760188 and https://www.guenther-eichhorn.com/images/UGANDA/Uganda_0696_1536x1024.jpg and https://www.flickr.com/photos/7332125@N04/13980721829).

In several other subspecies, there is individual variation:

Equus quagga burchellii https://www.istockphoto.com/photo/side-profile-of-a-zebra-in-etosha-gm825527988-133903295 and https://www.alamy.com/stock-photo-burchells-zebra-equus-quagga-burchellii-also-known-as-the-damara-zebra-86220478.html and https://www.alamy.com/burchells-zebra-equus-burchelli-hindquarters-etosha-n-p-namibia-south-image911649.html and https://www.alamy.com/stock-photo-plains-zebra-equus-quagga-from-the-back-etosha-national-park-namibia-31067660.html

Equus quagga chapmani https://www.alamy.com/stock-photo-burchells-zebra-equus-burchellii-ear-markings-rietvlei-nature-reserve-125476878.html and https://www.alamy.com/stock-image-the-back-of-a-zebra-madikwe-game-reserve-164693118.html and https://www.inaturalist.org/observations/43376288 and https://www.inaturalist.org/observations/52649218

Equus quagga boehmi https://www.alamy.com/stock-photo-boehms-zebra-grants-zebra-equus-quagga-boehmi-equus-quagga-granti-58075935.html and https://www.alamy.com/wildlife-in-the-serengeti-image263633941.html and https://www.shutterstock.com/nb/image-photo/zebras-nature-731626081 and https://stock.adobe.com/images/zebra-from-behind/29680226 and https://www.shutterstock.com/nb/image-photo/back-lonely-zebra-walking-through-green-1933756202 and https://www.alamy.com/close-up-of-zebra-image265320809.html

The only extant subspecies in which I have yet to see any individual with an auricular flag is E. q. crawshayi (https://www.alamy.com/sunlight-shining-on-ginger-tipped-mane-of-endemic-crawshays-zebra-equus-quagga-crawshayi-in-golden-dry-grassland-of-south-luangwa-zambia-africa-image327537238.html and https://www.alamy.com/zambia-south-luangwa-national-park-mfuwe-crawshays-zebra-wild-equus-quagga-crawshayi-computer-enhanced-image389661340.html and https://www.alamy.com/stock-photo-crawshays-zebra-mother-and-foal-equus-quagga-crawshayi-south-luangwa-86003544.html).

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 (https://www.google.com.au/search?q=Equus+quagga+burchellii+hluhluwe+imfolozi&tbm=isch&ved=2ahUKEwj9m_3hovXyAhXNXysKHUQ1BsAQ2-cCegQIABAA&oq=Equus+quagga+burchellii+hluhluwe+imfolozi&gs_lcp=CgNpbWcQAzoECAAQQzoFCAAQgAQ6BggAEAcQHjoECAAQGFCZynBYm8RxYPnUcWgBcAB4AIABngKIAcgxkgEEMi0yOZgBAKABAaoBC2d3cy13aXotaW1nwAEB&sclient=img&ei=hsM7Yf3AL82_rQHE6piADA&bih=552&biw=1013#imgrc=fpS9H49m7qejSM and http://www.wildafrica.sk/index_soubory/SOUTH%20AFRICAN%20MUSEUM%20in%20CAPE%20TOWN/album/slides/PA121696.html). 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.

Ingresado el 09 de septiembre de 2021 por milewski milewski | 3 comentarios | Deja un comentario

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 https://geology.com/world/south-africa-satellite-image.shtml) 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 https://proxy.europeana.eu/90402/RP_T_1914_17_189?view=https%3A%2F%2Flh3.googleusercontent.com%2F3JVvYAinrEi1oFK84S6WTwm7OH1qI8RV6RGTqbvOZ86qiwActBN3TJ0GTIlNCIKdF1Sp9np0bvEsZdelndCHlgMTCQ%3Ds0&disposition=inline&api_url=https%3A%2F%2Fapi.europeana.eu%2Fapi and https://en.wikipedia.org/wiki/Burchell%27s_zebra) 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.

Ingresado el 09 de septiembre de 2021 por milewski milewski | 1 comentario | Deja un comentario
Vida Silvestre es una entidad asociada a la Organización Mundial de Conservación