Canis is a genus of the Caninae which includes multiple extant species, such as wolves, dogs, coyotes, and golden jackals. Species of this genus are distinguished by their moderate to large size, their massive, well-developed skulls and dentition, long legs, and comparatively short ears and tails.
Taxonomy
The genus Canis (Carl Linnaeus, 1758) was published in the 10th edition of Systema Naturae
In 2019, a workshop hosted by the IUCN/SSC Canid Specialist Group recommends that because DNA evidence shows the side-striped jackal (Canis adustus) and black-backed jackal (Canis mesomelas) to form a monophyletic lineage that sits outside of the Canis/Cuon/Lycaon clade, that they should be placed in a distinct genus, Lupulella Hilzheimer, 1906 with the names Lupulella adusta and Lupulella mesomelas. and the position of the canids would change to become a dominant predator across the Palearctic. The wolf-sized C. chihliensis appeared in northern China in the Mid-Pliocene around 4-3 million YBP. This was followed by an explosion of Canis evolution across Eurasia in the Early Pleistocene around 1.8 million YBP in what is commonly referred to as the wolf event. It is associated with the formation of the mammoth steppe and continental glaciation. Canis spread to Europe in the forms of C. arnensis, C. etruscus, and C. falconeri. In a study done in 2017, it was found that in some species of canids females use their sexual status to gain food resources. The study looked at wolves and dogs. Wolves are typically monogamous and form pair-bonds; whereas dogs are promiscuous when free-range and mate with multiple individuals. The study found that in both species females tried to gain access to food more and were more successful in monopolizing a food resource when in heat. Outside of the breeding season their efforts were not as persistent or successful. This shows that the food-for-sex hypothesis likely plays a role in the food sharing among canids and acts as a direct benefit for the females. They found that females in heat searched out dominant males and were more likely to mate with a dominant male who appeared to be a quality leader. The females were more likely to reject submissive males. Furthermore, cases of male-male competition were more aggressive in the presence of high ranking females. This suggests that females prefer dominant males and males prefer high ranking females meaning social cues and status play a large role in the determination of mating pairs in dogs. The studied looked at coyote mating pairs and found that paternal investment was increased to match or near match the maternal investment. The amount of parental care provided by the fathers also was shown to fluctuated depending on the level of care provided by the mother.
Another study on parental investment showed that in free-ranging dogs, mothers modify their energy and time investment into their pups as they age. Due to the high mortality of free-range dogs at a young age a mother's fitness can be drastically reduced. This study found that as the pups aged the mother shifted from high-energy care to lower-energy care so that they can care for their offspring for a longer duration for a reduced energy requirement. By doing this the mothers increasing the likelihood of their pups surviving infancy and reaching adulthood and thereby increase their own fitness.
A study done in 2017 found that aggression between male and female gray wolves varied and changed with age. Males were more likely to chase away rival packs and lone individuals than females and became increasingly aggressive with age. Alternatively, females were found to be less aggressive and constant in their level of aggression throughout their life. This requires further research but suggests that intersexual aggression levels in gray wolves relates to their mating system.
Tooth breakage
thumb|200px|Dentition of a wolf showing functions of the teeth.
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Tooth breakage is a frequent result of carnivores' feeding behaviour. Species that are too small to attract the word "wolf" are called coyotes in the Americas and jackals elsewhere. Although these may not be more closely related to each other than they are to C. lupus, they are, as fellow Canis species, more closely related to wolves and domestic dogs than they are to foxes, maned wolves, or other canids which do not belong to the genus Canis. The word "jackal" is applied to the golden jackal (C. aureus), found across southwestern and south-central Asia, and the Balkans in Europe.
African migration
The first record of Canis on the African continent is Canis sp. A from South Turkwel, Kenya, dated 3.58–3.2 million years ago. In 2015, a study of mitochondrial genome sequences and whole genome nuclear sequences of African and Eurasian canids indicated that extant wolf-like canids have colonised Africa from Eurasia at least 5 times throughout the Pliocene and Pleistocene, which is consistent with fossil evidence suggesting that much of the African canid fauna diversity resulted from the immigration of Eurasian ancestors, likely coincident with Plio-Pleistocene climatic oscillations between arid and humid conditions. In 2017, the fossil remains of a new Canis species, named Canis othmanii, was discovered among remains found at Wadi Sarrat, Tunisia, from deposits that date 700,000 years ago. This canine shows a morphology more closely associated with canids from Eurasia instead of Africa.
Gallery
<gallery mode="packed">
File:Canis lupus signatus - 01.jpg|Gray wolf (Canis lupus)
File:Washtenaw County's last wolf (1907).jpg|Eastern wolf (Canis lycaon) (includes latrans admixture)
File:Red wolf (4531335218).jpg|Red wolf (Canis rufus) (includes latrans admixture)
File:USMC-11557.jpg|Coyote (Canis latrans)
File:Golden wolf small.jpg|African wolf (Canis lupaster)
File:Flickr - Rainbirder - Golden Jackal.jpg|Golden jackal (Canis aureus)
File:Canis simensis.jpg|Ethiopian wolf (Canis simensis)
File:Tibetan Wolf By Stanzin (Stakpa).jpg|Himalayan wolf (Canis lupus chanco)
File:Indian Wolf Male.jpg|Indian wolf (Canis lupus pallipes)
File:20110425 German Shepherd Dog 8505.jpg|Domestic dog (Canis familiaris)
</gallery>
See also
- List of canids