Editing Canis (section)

===Description and sexual dimorphism===
{{multiple image|perrow=4|total_width=500|image2=Lactating Female Coyote - cropped.jpg|image1=Coyote 05282020000047416 (49945760021).jpg
|image4=Female_Gray_Wolf_(6045671049).jpg|image3=20140812 WOLF IMG 1043.png
|caption1=Male coyote|caption2=Female coyote|caption3=Male gray wolf|caption4=Female gray wolf}}

There is little variance among male and female canids. Canids tend to live as monogamous pairs. Wolves, [[dholes]], [[coyote]]s, and [[jackals]] live in groups that include [[breeding pair]]s and their offspring. Wolves may live in extended family groups. To take prey larger than themselves, the African wild dog, the dhole, and the gray wolf depend on their jaws as they cannot use their forelimbs to grapple with prey. They work together as a pack consisting of an alpha pair and their offspring from the current and previous years.<ref name=valkenburgh2002/> Social mammal predators prey on herbivores with a body mass similar to that of the combined mass of the predator pack.<ref name=sorkin2008/><ref name=earle1987/> The gray wolf specializes in preying on the vulnerable individuals of large prey,<ref name=paquet2003/> and a pack of timber wolves can bring down a {{convert|500|kg|lb|abbr=on}} moose.<ref name=mech1966/><ref name=anyonge2006/>

==== Mating behaviour ====
The genus ''Canis'' contains many different species and has a wide range of different mating systems that varies depending on the type of canine and the species.<ref name="Current Zoology">{{Cite journal|last1=Dale|first1=Rachel|last2=Marshall-Pescini|first2=Sarah|last3=Range|first3=Friederike|date=2017-06-01|title=Do females use their sexual status to gain resource access? Investigating food-for-sex in wolves and dogs|journal=Current Zoology|language=en|volume=63|issue=3|pages=323–330|doi=10.1093/cz/zow111|pmid=29491991|pmc=5804177|issn=1674-5507}}</ref> 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. [[Gray wolf|Wolves]] are typically [[Monogamy in animals|monogamous]] and form [[pair bond|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.<ref name="Current Zoology"/>

Another study on [[free-ranging dog]]s found that social factors played a significant role in the determination of mating pairs. The study, done in 2014, looked at social regulation of reproduction in the dogs.<ref name="Social Variables Affecting Mate Preferences, Copulation and Reproductive Outcome in a Pack of Free-Ranging Dogs">{{Cite journal|last1=Cafazzo|first1=Simona|last2=Bonanni|first2=Roberto|last3=Valsecchi|first3=Paola|last4=Natoli|first4=Eugenia|date=2014-06-06|title=Social Variables Affecting Mate Preferences, Copulation and Reproductive Outcome in a Pack of Free-Ranging Dogs|journal=PLOS ONE|language=en|volume=9|issue=6|pages=e98594|doi=10.1371/journal.pone.0098594|pmid=24905360|pmc=4048177|bibcode=2014PLoSO...998594C|issn=1932-6203|doi-access=free}}</ref> They found that females in [[Estrus|heat]] searched out [[dominance (ethology)|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.<ref name="Social Variables Affecting Mate Preferences, Copulation and Reproductive Outcome in a Pack of Free-Ranging Dogs"/>

Canids also show a wide range of [[parental care]] and in 2018 a study showed that [[sexual conflict]] plays a role in the determination of [[Parental investment|intersexual parental investment]].<ref>{{Cite journal|last1=Schell|first1=Christopher J|last2=Young|first2=Julie K|last3=Lonsdorf|first3=Elizabeth V|last4=Mateo|first4=Jill M|last5=Santymire|first5=Rachel M|title=It takes two: Evidence for reduced sexual conflict over parental care in a biparental canid|journal=Journal of Mammalogy|volume=99|issue=1|pages=75–88|doi=10.1093/jmammal/gyx150|year=2018|doi-access=free}}</ref> 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.<ref>{{Cite journal|last1=Paul|first1=Manabi|last2=Sau|first2=Shubhra|last3=Nandi|first3=Anjan K.|last4=Bhadra|first4=Anindita|date=2017-01-01|title=Clever mothers balance time and effort in parental care: a study on free-ranging dogs|journal=Royal Society Open Science|language=en|volume=4|issue=1|pages=160583|doi=10.1098/rsos.160583|pmid=28280555|pmc=5319321|issn=2054-5703|arxiv=1607.01135|bibcode=2017RSOS....460583P}}</ref> 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.<ref>{{Cite journal|last1=Cassidy|first1=Kira A.|last2=Mech|first2=L. David|last3=MacNulty|first3=Daniel R.|last4=Stahler|first4=Daniel R.|last5=Smith|first5=Douglas W.|title=Sexually dimorphic aggression indicates male gray wolves specialize in pack defense against conspecific groups|journal=Behavioural Processes|volume=136|pages=64–72|doi=10.1016/j.beproc.2017.01.011|pmid=28143722|year=2017|s2cid=32107025|url=https://digitalcommons.unl.edu/usgsnpwrc/311|url-access=subscription}}</ref> 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 [[Wolf|gray wolves]] relates to their [[mating system]].

====Tooth breakage====
[[File:Wolf dentition in the Ice Age.svg|thumb|200px|Dentition of a wolf showing functions of the teeth.]]

<!--Note: [[Dire wolf]] and [[Beringian wolf]] both link to here.-->
Tooth breakage is a frequent result of carnivores' feeding behaviour.<ref name=valkenburgh1993a/> Carnivores include both [[pack hunter]]s and solitary hunters. The solitary hunter depends on a powerful bite at the canine teeth to subdue their prey, and thus exhibits a strong [[mandibular symphysis]]. In contrast, a pack hunter, which delivers many shallower bites, has a comparably weaker mandibular symphysis. Thus, researchers can use the strength of the mandibular symphysis in fossil carnivore specimens to determine what kind of hunter it was{{snd}}a pack hunter or a solitary hunter{{snd}}and even how it consumed its prey. The mandibles of canids are buttressed behind the carnassial teeth to crack bones with their post-carnassial teeth (molars M2 and M3). A study found that the modern gray wolf and the red wolf (''C.{{nbsp}}rufus'') possess greater buttressing than all other extant canids and the extinct dire wolf. This indicates that these are both better adapted for cracking bone than other canids.<ref name=therrien2005/>

A study of nine modern carnivores indicate that one in four adults had suffered tooth breakage and that half of these breakages were of the canine teeth. The highest frequency of breakage occurred in the spotted hyena, which is known to consume all of its prey including the bone. The least breakage occurred in the [[African wild dog]]. The gray wolf ranked between these two.<ref name=valkenburgh1993a/><ref name=valkenburgh1988/> The eating of bone increases the risk of accidental fracture due to the relatively high, unpredictable stresses that it creates. The most commonly broken teeth are the canines, followed by the premolars, carnassial molars, and incisors. Canines are the teeth most likely to break because of their shape and function, which subjects them to bending stresses that are unpredictable in direction and magnitude.<ref name=valkenburgh1988/> The risk of tooth fracture is also higher when taking and consuming large prey.<ref name=valkenburgh1988/><ref name=desantis2015/>
 
In comparison to extant gray wolves, the extinct [[Beringian wolf|Beringian wolves]] included many more individuals with moderately to heavily worn teeth and with a significantly greater number of broken teeth. The frequencies of fracture ranged from a minimum of 2% found in the [[Northern Rocky Mountain wolf]] ''(Canis lupus irremotus)'' up to a maximum of 11% found in Beringian wolves. The distribution of fractures across the tooth row also differs, with Beringian wolves having much higher frequencies of fracture for incisors, carnassials, and molars. A similar pattern was observed in spotted hyenas, suggesting that increased incisor and carnassial fracture reflects habitual bone consumption because bones are gnawed with the incisors and then cracked with the carnassials and molars.<ref name=leonard2007/>