Testing the idea of a new ancestor (Canis rubronegrus) for the domestic dog: do extant wolves/jackals show traces of black-and-tan colouration? part 1

Does the 'black-and-tan' pattern in the domestic dog (Canis familiaris) indicate an extinct, previously unsuspected ancestor?

This 'primeval' pattern occurs with remarkable frequency and consistency in many breeds, including otherwise extremely modified breeds.

The colouration of the pelage is typically blackish (ground colour) and reddish-brown (various features arranged from the face and feet to the posterior, in a composite pattern).

However, the colours 'black' and 'tan', as such, are not what we should focus on, because the actual tones and hues vary greatly.

Instead, what is noteworthy is that a relatively dark tone on the crown, nape, back, flanks, rump, and upper legs is offset by a relatively pale tone on various peripheral parts of the figure, with an elaborate configuration of distinct borders between the two tones.

The following illustrate this bilaterally symmetrical pattern, in which 'black' and 'tan' are indicative rather than literal descriptors:

https://www.alamy.com/stock-photo-two-mixed-breed-dogs-sitting-on-a-meadow-an-australian-shepherd-mix-74748500.html?imageid=5E291224-4712-49DA-9F74-3318E3F9FAE6&p=129618&pn=1&searchId=3a787f731934bffa2ab9303459f4b455&searchtype=0
https://www.alamy.com/australian-tradition-sheepdog-kelpie-image539137523.html?imageid=EE0E40D2-8322-4D9A-B3E3-D34C0FE5EB61&p=2049021&pn=1&searchId=e8e90d20091ba4bd58c309522bd915a8&searchtype=0
https://www.bing.com/images/search?view=detailV2&ccid=AR3MfWpG&id=6077AC2A893A8E51E38EA10947AD18E7BD7B9BDA&thid=OIP.AR3MfWpGAXh7UtlIswtKrgHaFw&mediaurl=https%3A%2F%2Fth.bing.com%2Fth%2Fid%2FR.011dcc7d6a4601787b52d948b30b4aae%3Frik%3D2pt7vecYrUcJoQ%26riu%3Dhttp%253a%252f%252fwww.visiontimes.com%252fuploads%252f2015%252f06%252fkelpie-smiling-shot-Image-Janus-Serendipityflickr.jpg%26ehk%3DhapGpk9G%252f7V4Jp7iyrRsXBCPnuwmlcteNNbEi1QrAes%253d%26risl%3D%26pid%3DImgRaw%26r%3D0&exph=389&expw=500&q=black+and+tan+kelpie+face+close-up&simid=607997868877181912&form=IRPRST&ck=72ADF86FAE10065B23EEE855EF8D1787&selectedindex=11&itb=0&ajaxhist=0&ajaxserp=0&vt=0&sim=11
https://www.bing.com/images/search?view=detailV2&ccid=5DCGSbMW&id=D89E641525DA04C72F761D6DE06D3D50FCD393A3&thid=OIP.5DCGSbMWpGtU6X1M9xPRaQHaE8&mediaurl=https%3A%2F%2Fwww.austockphoto.com.au%2Fimgcache%2Fuploads%2Fphotos%2Fcompressed%2Fclose-up-of-an-australian-kelpie-austockphoto-000055355.jpg%3Fv%3D1.3.5&exph=667&expw=1000&q=black+and+tan+kelpie+face+close-up&simid=608022071000565025&form=IRPRST&ck=AD0D5A8E08DC8F3F7EEFFCC78EE69E0C&selectedindex=3&itb=0&ajaxhist=0&ajaxserp=0&vt=0&sim=11
https://coatsandcolors.com/tan-points-black-back/
https://www.smartdogguide.com/black-and-tan-dog-breeds/

The pattern is complete already at birth (https://stock.adobe.com/images/three-rottweiler-puppies-joyfully-running-down-a-sidewalk/635216649?prev_url=detail).

The systemic integrity of the black-and-tan pattern suggests that it has been inherited from whichever species is the main wild ancestor of the domestic dog.

This is as opposed to its having been recently created by the non-adaptive mutations so typical of domestic animals.

Furthermore, it is unlikely that selection by human breeders of the domestic dog would have produced a distinct and individually variable - but nonetheless symmetrical - ischial feature.

I refer to a 'natural-looking' pale patch on the buttocks (https://www.dreamstime.com/small-mixed-breed-dog-rear-view-doggy-ass-image238430255), which is intrinsic to the black-and-tan pattern.

It seems unlikely that the ischial feature (https://www.dreamstime.com/little-chihuahua-park-small-breeds-dogs-pet-must-walk-outdoors-portrait-dog-brown-summer-walks-garden-image186211490) is anthropogenic, because canine buttocks are not an aesthetic locus in human eyes.

There are hundreds of millions of photos of the domestic dog on the Web, but it is hard to find any that focus on the buttocks, beyond veterinary illustrations. Most of the few depictions of the ischial feature available on the Web are inadvertent/fortuitous (https://www.shutterstock.com/video/clip-15333361-alone-black-dog-running-on-beach).
One exception is https://www.reddit.com/media?url=https%3A%2F%2Fi.redd.it%2Fuoq3lv2lzae61.jpg.

For these reasons, I have invoked an extinct, previously unsuspected ancestor, and dubbed this 'Canis rubronegrus' (https://www.inaturalist.org/journal/milewski/56803-an-extinct-canid-hiding-in-plain-sight-in-the-domestic-dog#).

A major aspect of the rationale for Canis rubronegrus as the main ancestor of the domestic dog is that no extant wild species of Canis, including the wolf (Canis lupus), shows the black-and-tan colouration.

However, let us play devil's advocate (https://dictionary.cambridge.org/dictionary/english/devil-s-advocate).

A possible counter-rationale is as follows:

  • The pattern in question occurs in partial and residual/incipient form in all of the extant wild spp. of Canis.
  • This includes the wolf, which has certainly been a partial ancestor of the domestic dog, and is - according to most authors - its main ancestor.
  • These traces might, theoretically, have been accentuated anthropogenically - albeit inadvertently - along with the other changes in colouration in the derivation of the domestic dog from the wolf.

I have written this Post in the spirit of testing my own hypothesis.

This leads me to confirm that, in detraction from my hypothesis:

However:

Overall, the evidence I present in this Post supports the idea that the main ancestor of the domestic dog was an extinct, jackal-like species (Canis rubronegrus), the full black-and-tan pattern of which is still expressed today in, for example,

FEATURES OF THE BLACK-AND-TAN COLOURATION

Bucco-gular:

Please see around the mouth, extending to the crook-of-throat, in https://www.alamy.com/dog-hovawart-portrait-black-and-tan-adult-in-nature-face-attentive-image68278597.html?imageid=B2B698CC-1417-4007-9DD9-F940A6BD8DD5&p=42566&pn=1&searchId=92c543405934c1085c6f6e364c095cce&searchtype=0 and https://a-z-animals.com/animals/australian-kelpie-dog/pictures/ and https://www.alamy.com/stock-photo-dog-hovawart-portrait-black-and-tan-adult-in-nature-face-attentive-52603203.html?imageid=4D718D7C-4460-41D5-B7C4-76F470BD96F4&p=42566&pn=1&searchId=92c543405934c1085c6f6e364c095cce&searchtype=0 and https://www.alamy.com/stock-photo-hovawart-canis-lupus-f-familiaris-black-and-gold-portrait-germany-58218942.html?imageid=95DE2207-CF56-43B5-A8A2-D40DCF492236&p=34140&pn=1&searchId=92c543405934c1085c6f6e364c095cce&searchtype=0.

Superciliary:

Please see the eyebrows in https://www.abc.net.au/news/2016-02-19/mans-best-friend-how-love-of-kelpies-being-shared-with-community/7183044 and https://www.facebook.com/photo/?fbid=588706289587548&set=pb.100053445465977.-2207520000 and https://www.alamy.com/stock-photo-close-up-of-a-black-and-tan-hound-mixed-breed-dog-with-floppy-ears-172135288.html and https://www.alamy.com/australian-kelpie-image416862228.html?imageid=C18CA8EF-DE67-40AD-A113-C26037B1B234&p=28064&pn=1&searchId=3a787f731934bffa2ab9303459f4b455&searchtype=0.

Pectoral:

Please see the chest in https://www.bestmatedogtraining.co.nz/training-kelpies and https://www.alamy.com/australian-kelpie-black-and-tan-image226769664.html?imageid=555E1073-C1D7-47B3-938F-B283E22813C7&p=28064&pn=1&searchId=ab08e945bb3f16457c6b9e8e0d8f9f94&searchtype=0 and https://www.alamy.com/stock-photo-dog-working-kelpie-young-sitting-in-a-meadow-53930486.html and https://www.greatpetcare.com/dog-breeds/australian-kelpie/.

Pedal (fore and hind):

Please see the fore- and hindfeet in https://stock.adobe.com/images/rottweiler-in-nature/709593598?prev_url=detail and https://www.alamy.com/young-australian-kelpie-image491320722.html?imageid=BA281443-D27B-4F4C-AA1E-A426DB5AF11F&p=170971&pn=1&searchId=e8e90d20091ba4bd58c309522bd915a8&searchtype=0 and https://www.dreamstime.com/stock-photography-saluki-side-view-healthy-beautiful-grizzle-black-tan-standing-lawn-looking-happy-cheerful-persian-greyhound-image35120252 and https://www.shutterstock.com/image-photo/large-black-tan-dog-stands-on-2329303745 and https://www.shutterstock.com/image-photo/black-tan-dog-japanese-shiba-inu-1812596953 and https://caninechronicle.com/health-training/feet-dont-fail-me-now/ and scroll to fourth photo in https://www.rover.com/blog/why-is-my-dog-limping/ and https://www.istockphoto.com/photo/saluki-gm497751364-79294547 and https://www.alamy.com/stock-photo-australian-kelpie-playing-on-porthmeor-beach-in-st-ives-cornwall-33913424.html?imageid=D535008D-35C3-4AA0-AF0D-19B01001D614&p=42090&pn=2&searchId=45b013a4eb19a452136b64abfc6a0af9&searchtype=0.

Ischial:

Please see the buttocks in https://www.istockphoto.com/photo/image-of-rear-end-of-inquisitive-wild-stray-puppy-dog-looking-at-the-camera-in-park-gm1131790642-299794668 and https://www.dogbreedinfo.com/care/infectedanalglands.htm and https://www.shutterstock.com/image-photo/beautiful-rottweiler-purebred-outdoor-butt-natural-1984356554 and https://www.dreamstime.com/small-mixed-breed-dog-rear-view-doggy-ass-small-mixed-breed-dog-rear-view-doggy-ass-image238605105 and https://www.shutterstock.com/image-photo/pregnant-black-tan-dog-miniature-pinscher-2299224219 and https://www.shutterstock.com/image-photo/dog-bum-raised-tail-back-visible-1828105421 and https://www.shutterstock.com/image-photo/black-tan-coonhound-reaching-on-white-191231801 and https://www.shutterstock.com/image-photo/bum-dog-animal-mammal-puppy-pedigree-2326360035 and https://www.shutterstock.com/image-photo/funny-bull-terrier-hind-legs-185541173 and https://www.shutterstock.com/image-photo/cute-dachshund-dog-black-tan-pushed-1651841341 and https://www.bigstockphoto.com/image-345101983/stock-photo-black-and-tan-dog-butt-and-tail-sticking-out-from-under-the-white-blanket-on-the-bed-home-or-dog-fr and https://www.dreamstime.com/australian-kelpie-dog-runs-plays-sand-next-to-river-australian-kelpie-dog-image132705472

A peculiarity of the ischial feature (which in some individuals may qualify as an ischial flag) is that it contains a hair-whorl (https://pubmed.ncbi.nlm.nih.gov/20101738/#:~:text=The%20majority%20of%20whorls%20on,and%20source%20of%20the%20dog.). According to my observations, this hair-whorl is remarkably variable among individuals, a point hard to illustrate because few close-up photos are available on the Web.

Throughout this Post, I ignore

SPECIES-BY-SPECIES EXAMINATION

Canis latrans

The only features of the black-and-tan pattern in the coyote (Canis latrans) are the bucco-gular (https://www.shutterstock.com/image-photo/coyotes-highly-adaptable-canids-found-throughout-2392307005) and pectoral features.

However, there has been widespread hybridisation between the coyote and both the wolf and the domestic dog. Therefore, the pectoral feature may have been absent in the coyote prior to anthropogenic influence.

https://www.smithsonianmag.com/smithsonian-institution/coyotes-infiltrate-south-america-180974016/
https://www.shutterstock.com/image-photo/coyote-pup-wild-den-1472163530
https://www.offset.com/search/coyote+howling
https://www.berkeleyside.org/2017/12/21/new-dogs-town-coyotes-expert-camilla-fox-co-existing
https://discoverwildcare.org/kesslerjanet_coyote-sitting-cross-legged/
https://www.mediastorehouse.com.au/design-pics/update-march-23-2022/coyote-sitting-snow-covered-field-looking-24610736.html
Scroll to 20th photo in https://www.theguardian.com/environment/gallery/2021/dec/03/the-week-in-wildlife-in-pictures
https://www.shutterstock.com/image-photo/coyote-on-prowl-food-1917673649
https://www.featheredphotography.com/blog/2020/08/29/coyote-with-raised-hackles/

Canis lupus

In the wolf, as in the coyote, virtually the only features of the black-and-tan pattern are the bucco-gular and pectoral features.

The bucco-gular feature is particularly conspicuous in some individuals.

This is partly because it is extended by/has coalesced with an enlarged, whitish maxillary feature (https://www.businessinsider.com/almost-20-of-yellowstone-parks-gray-wolves-killed-by-hunters-2022-1 and https://arkvalleyvoice.com/whos-afraid-of-the-big-bad-wolf/ and https://kids.nationalgeographic.com/animals/mammals/facts/gray-wolf and https://upload.wikimedia.org/wikipedia/commons/2/2e/Canis_lupus_2_%28Martin_Mecnarowski%29.jpg). However, the superciliary feature is absent.

The wolf has been hybridised (except possibly on Arctic islands) with the domestic dog.

Therefore, the pectoral feature - which is always indistinct in the wolf - may possibly be attributed to Canis rubronegrus, via hybridisation with C. familiaris. The same applies to the superciliary feature, which is slightly expressed in some individuals of the wolf (usually said by extension of the buccal component).

If so, this hybridisation has not conferred any noticeable ischial feature. The buttocks have unremarkable colouration in the wolf (https://www.istockphoto.com/photo/north-american-grey-wolf-canis-lupus-occidentalis-adult-with-prey-canada-gm1215347874-353953429?phrase=wolf+rear+view&searchscope=image%2Cfilm and https://www.dreamstime.com/grey-wolf-canis-lupus-steps-left-nose-down-tail-up-winter-captive-animal-image191941014 and https://www.shutterstock.com/image-photo/lone-wolf-fortunate-enough-capture-these-1414402826 and https://www.outdoorlife.com/conservation/wolf-vs-coyote/ and https://www.shutterstock.com/image-photo/walking-gray-wolf-isolated-on-white-1846608109 and https://www.flickr.com/photos/fotrristi/438912581 and https://www.cleanwisconsin.org/under-the-lens-wisconsins-wolves/ and https://www.alamy.com/wolves-canis-lupus-look-up-from-body-of-white-tail-deer-winter-captive-animals-image510123231.html?imageid=534B2E3D-2C01-49D4-BC6F-9B7648C94EC7&p=1336092&pn=1&searchId=e2b574903d30098d473fec23533b83f3&searchtype=0 and https://www.istockphoto.com/photo/rear-view-of-grey-wolf-standing-in-winter-snow-day-gm933472764-255722574) and https://wolfsanctuarypa.org/2013/12/15/wolf-communication-part-2-body-language/.

The feet are extremely pale in some individuals of the wolf (https://www.courthousenews.com/eu-looks-to-downgrade-wolf-protection-status/). However, the border is too nebulous to for this to be ancestral to the black-and-tan pattern.

https://www.flickr.com/photos/hellie55/11006866076/in/photostream/
https://www.istockphoto.com/photo/canadian-timberwolf-gm1208811811-349547080?phrase=wolf+sitting&searchscope=image%2Cfilm
https://mymodernmet.com/mexican-gray-wolf-family-perfect-pose/
https://upload.wikimedia.org/wikipedia/commons/6/68/Eurasian_wolf_2.jpg
https://www.istockphoto.com/photo/gray-wolf-in-winter-gm865346476-143651721?phrase=wolf+rear+view&searchscope=image%2Cfilm

Canis simensis

The kekebero (Canis simensis) is, of all the extant wild spp. of Canis, the one with the most distinct colouration (https://www.inaturalist.org/journal/milewski/54541-advertisement-colouration-in-a-carnivore-the-kekebero-canis-simensis#).

However, even this species differs from the black-and-tan pattern in that the following are absent:

  • the superciliary feature, and
  • the ischial feature.

The whitish pelage adjacent to the base of the tail (https://www.alamy.com/ethiopian-wolf-canis-simensis-bale-mountains-national-park-bale-zone-oromia-region-ethiopia-image228699285.html) is not the same as the ischial feature. It is part of a caudal flag, not an ischial flag.

Furthermore,

  • the pale pelage on the inner (medial) surface of the forefoot extends (as in some individuals of the wolf) nearly as far as the elbow, and
  • the pedal feature on the hindfoot is less, not more, distinct than in the domestic dog.

https://www.alamy.com/ethiopian-wolf-canis-simensis-beautiful-endangered-wolf-endemic-in-ethiopian-hills-bale-mountains-ethiopia-image432062594.html?imageid=6C20BA18-A72F-4E6B-9FFB-8CEA19370C1F&p=441453&pn=1&searchId=5465877b37e485a64aa9ff7ec21a7f64&searchtype=0
https://www.alamy.com/stock-photo-ethiopian-wolf-canis-simensis-adult-pair-greeting-each-other-bale-47780826.html?imageid=64F00DC1-B2BD-43B2-A63A-B14A09BCEE14&p=11592&pn=1&searchId=5465877b37e485a64aa9ff7ec21a7f64&searchtype=0
https://www.youtube.com/watch?v=XxuB6jTLRUo
https://www.alamy.com/stock-photo-ethiopian-wolf-canis-simensis-bale-mountains-national-park-ethiopia-102084286.html

Canis anthus

The black-and-tan pattern is absent from the North African jackal (Canis anthus), except for the bucco-gular feature. Like the coyote, this species has colouration too nondescript to be a candidate for main ancestor of the domestic dog.

http://www.arthurgrosset.com/mammals/photos/canaur46317.jpg
https://www.alamy.com/stock-photo-serengeti-jackal-canis-aureus-bea-in-serengeti-tanzania-140360809.html?imageid=BB6299C0-588F-49D2-A774-950032851417&p=355562&pn=1&searchId=24cfa12087a040767cf9d8cf8ec3708a&searchtype=0
https://www.shutterstock.com/image-photo/new-species-wolf-has-been-discovered-1620009874
https://www.shutterstock.com/image-photo/alert-golden-jackal-on-dirt-road-41291833
https://www.alamy.com/golden-jackal-or-african-golden-wolf-image404876864.html?imageid=C2144EB8-9AF1-4280-BB8E-F505AD96B07F&p=1403818&pn=1&searchId=24cfa12087a040767cf9d8cf8ec3708a&searchtype=0
https://www.alamy.com/stock-photo-african-golden-wolf-which-goes-on-savanna-and-bears-in-the-mouth-food-138982732.html?imageid=D81B9F33-A2CF-4FDC-AF88-8796174EAD06&p=174701&pn=1&searchId=24cfa12087a040767cf9d8cf8ec3708a&searchtype=0
https://www.alamy.com/stock-photo-golden-common-jackal-canis-aureus-prowling-in-grassland-in-tanzania-176107324.html?imageid=AA9F53CD-5655-4E06-B97C-32F51C420D72&p=79480&pn=1&searchId=24cfa12087a040767cf9d8cf8ec3708a&searchtype=0
https://www.alamy.com/african-golden-wolf-next-to-a-lagoon-image483709393.html?imageid=416E3357-ABA4-47EB-AB02-45065C589ABA&p=1403856&pn=1&searchId=24cfa12087a040767cf9d8cf8ec3708a&searchtype=0 and https://www.alamy.com/african-golden-wolf-next-to-a-lagoon-image483709385.html?imageid=1DC1D7C8-C586-4479-9C76-3A4E9219F10B&p=1403856&pn=1&searchId=24cfa12087a040767cf9d8cf8ec3708a&searchtype=0 and https://www.alamy.com/african-golden-wolf-canis-lupaster-oiseaux-du-djoudj-national-park-saint-louis-senegal-image472893047.html?imageid=627951FA-887E-40EB-963C-B4A3901F1EA9&p=191838&pn=1&searchId=24cfa12087a040767cf9d8cf8ec3708a&searchtype=0
https://www.alamy.com/a-rare-african-golden-jackal-inside-the-ngorongoro-crater-tanzania-image553205214.html?imageid=85649119-AD8B-4436-B62C-D204513C85ED&p=2013911&pn=1&searchId=24cfa12087a040767cf9d8cf8ec3708a&searchtype=0
https://www.alamy.com/a-rare-african-golden-jackal-inside-the-ngorongoro-crater-tanzania-image553206765.html?imageid=D4EAA215-D671-4DFD-9237-0765A24C318D&p=2013911&pn=1&searchId=24cfa12087a040767cf9d8cf8ec3708a&searchtype=0

Canis aureus

The pectoral feature is expressed in the Asiatic jackal (Canis aureus), second only to the kekebero.

As in all spp. of Canis, the bucco-gular feature is present. Whereas the buccal (and maxillary) component is emphasised in the wolf, the gular component is emphasised in the Asiatic jackal (https://upload.wikimedia.org/wikipedia/commons/f/fd/Canis_aureus_syriacus_114837596.jpg).

All other features, including the superciliary feature, are absent.

https://www.istockphoto.com/photo/golden-jackal-gm182874123-13567793?phrase=wolf+rear+view&searchscope=image%2Cfilm
https://www.shutterstock.com/image-photo/european-golden-jackal-774860065
https://www.shutterstock.com/image-photo/golden-jackal-eraly-walk-grass-2347126171
https://www.shutterstock.com/image-photo/golden-jackal-nature-tracks-down-prey-2288985491
https://www.shutterstock.com/image-photo/sri-lankan-golden-jackal-wild-visit-2275582737
https://www.shutterstock.com/image-photo/indian-jackal-golden-2161236711
https://www.shutterstock.com/image-photo/jackal-pair-on-gravel-road-evening-1731786430
https://www.shutterstock.com/image-photo/indian-jackal-known-himalayan-subspecies-golden-2078234791
https://www.shutterstock.com/image-photo/golden-jackal-standing-on-ground-2065491584
https://www.alamy.com/the-golden-jackal-is-a-wolf-like-canid-that-is-native-to-southeast-europe-southwest-asia-south-asia-and-regions-of-southeast-asia-image379247761.html?imageid=BB7B0C02-F6B2-4F02-AD18-AAFE0F31C137&p=1307779&pn=1&searchId=24cfa12087a040767cf9d8cf8ec3708a&searchtype=0

to be continued in https://www.inaturalist.org/journal/milewski/89005-testing-the-idea-of-a-new-ancestor-canis-rubronegrus-for-the-domestic-dog-do-extant-wolves-jackals-show-traces-of-black-and-tan-colouration-part-2#...

Posted on January 19, 2024 09:31 AM by milewski milewski

Comments

A plausible adaptive function of the bucco-gular feature is to accentuate the facial expressions of both howling and fang-bearing, in which the pale pelage around the mouth contrasts with the dark bare skin of the lips and gums.

https://www.hcn.org/issues/40.20/still-howling-wolf

https://www.goodreads.com/review/show/2179185589

https://www.independent.co.uk/news/world/europe/wolf-german-forest-shepherd-environment-protected-endangered-species-a8102471.html

https://upload.wikimedia.org/wikipedia/commons/f/f8/Lupaster.png

In the domestic dog, the bucco-gular feature is usually not pale enough to perform a similar function (https://www.shutterstock.com/image-photo/aggressive-purebred-doberman-pinscher-176356241 and https://www.mediastorehouse.com.au/ardea-wildlife-pets-environment/dog-manchester-terrier-snarling-5285470.html).

Posted by milewski 5 months ago

The following shows clearly the distinction between the buccal feature, around the mouth, and the maxillary feature, on the cheek.

The superciliary feature, on the eyebrow, and the anterior auricular feature, on the front-of-ear, are also visible.

https://www.shutterstock.com/image-photo/doberman-dog-175942298

Posted by milewski 5 months ago

The descriptor 'black-and-tan' can be misleading in the following way.

It is often applied to the German shepherd and Airedale breeds (https://www.thesprucepets.com/black-and-tan-dog-breeds-5101326).

However, these breeds categorically exclude the pattern discussed in this Post. Their colouration has a different derivation, and they provide no evidence of an ancestor with the pattern that I attribute, hypothetically, to Canis rubronegrus.

Posted by milewski 5 months ago

Nice illustration of the camouflage effect of rubronegrus pattern (in faint form) in wild Canis aureus https://www.shutterstock.com/image-photo/golden-jackal-canis-aureus-danube-delta-1911484669

Posted by milewski 5 months ago

Nice illustration of cryptic colouration in Canis anthus bea, which lacks all the features of the rubronegrus colouration save a blurry form of the buccal pale feature, not in view here: https://www.alamy.com/stock-photo-serengeti-jackal-canis-aureus-bea-in-serengeti-tanzania-140360809.html?imageid=BB6299C0-588F-49D2-A774-950032851417&p=355562&pn=1&searchId=24cfa12087a040767cf9d8cf8ec3708a&searchtype=0

Posted by milewski 5 months ago
Posted by milewski 5 months ago

The following is NOT the black-and-tan pattern:

http://gsrelite.co.uk/breed-standards/

Posted by milewski 5 months ago

The following, in addition to showing an individual variant of the ischial flag, also shows the typical difference between fore- and hindfoot in the black-and-tan pattern. This is that the posterior surface of the forefoot is 'tan', whereas that of the hindfoot is 'black':

https://www.shutterstock.com/video/clip-15333361-alone-black-dog-running-on-beach

Posted by milewski 5 months ago

The German hunting terrier (https://en.wikipedia.org/wiki/Jagdterrier), a black-and-tan breed, is noteworthy. This is because the 'tan' features are diminished in size.

Posted by milewski 5 months ago

Is the following true?

A difference is that:

in most breeds of the domestic dog, the tail is narrow and held high, thus exposing the ischial surface, whereas
in all extant wild spp. of Canis, the tail is broad and held low, thus hiding the ischial surface (https://www.shutterstock.com/image-photo/lone-coyote-canis-latrans-walking-hunting-769189714).

Posted by milewski 5 months ago

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