A while ago, I read a publication by Mech L. D. et al. (2021) regarding Canis lupus domestication hypotheses.
Currently, there are two most prevalent theories.
One is that humans took wolf pups out of the dens as early as possible (around 3 weeks old) and raised them by hand in human settlements allowing for these wolves to only breed with other human-reared / human-bred wolves (preventing the breeding by domesticated wolves with wild wolves).
This hypothesis suggests that humans observed and appreciated some qualities in wolves that could benefit the early human hunter-gatherer communities (most likely, guarding the transitional settlements from other predators, scavengers etc. but also perhaps to have ‘mobile alternative meat resource’ that could be utilized upon necessity).
The other, less supported hypothesis, is that of self-domestication.
Namely, wolves approached human settlements to scavenge on discarded carcass leftovers and those wolves who exhibited signs of ‘greater friendliness’ were tolerated by humans and gradually became domesticated as humans realized the benefits such fed wolves that were ‘hanging around’ could provide (see also National Geographic article).
The second hypothesis is rather opposed by researchers on the grounds that humans at the time were very hostile toward any other predators whom they perceived as competition and wiped them out from the landscapes.
Also, if wolves arrived to scavenge, why would they attempt to even approach humans who were hostile to them?
The image of a dog begging for food by exhibiting ‘friendly, submissive behaviour’ is largely a contemporary notion and it is more likely (in my view) that wolves would have avoided notifying humans of their presence at all through trying to sneak some carrion away without ever becoming detected (as wolves appear to do even now when they scavenge on waste).
The first hypothesis, meanwhile, seems a bit strange to me for the reason that I have observed (in documentaries and research accounts) that wolves are not overly protective of their pups around humans.
They are protective, of course, for example, if there has been human presence near the den, wolves sometimes move the pups from the den afterwards which is why scientists tend to avoid intruding in den-sites while the pups are still there or they intrude only when pups are old enough to be moved more securely on occasion the wolf family decides to move following the intrusion.
At the same time, I have seen wolves who allow humans near their dens or even to catch a peek into their den.
This was demonstrated, for example, in the movie by the Dutchers (‘Living with Wolves’) where a female wolf who was otherwise rather aggressive, allowed the somewhat familiar female scientist to enter the den to take count of the pups.
Meanwhile, the scientists never dared to approach wolf kills as the wolves were feeding.
In many publications, pups are regarded quite equal to resources like food or territory.
If wolves were protective around food to the point that the scientists did not dare to approach, would they be less protective of their pups (on terms that our common history has informed wolves on the possible danger of their pups becoming snatched).
These are genetic behaviours influenced by the species history and made instinctive, as far as I understand it.
If humans had been intruding extensively into wolf dens to snatch their pups over prolonged periods of our pre-history in order to domesticate them, my assumption is that wolves would have developed a response of greater alarm with respect to humans approaching their pups and their dens.
Wolves are very protective of their pups and they are K-strategy mammals that invest in individual offspring development rather than producing numerous offspring and hoping that most of them would survive.
Wolves even demonstrate highly successful adoption rates raising pups that have been born to other wolves, including pups born to the former, displaced breeders (”enemies”) which means that the value the ‘pup resource’ greatly.
Additionally, the same publication by Mech et al. reports wolf behaviour on Ellesmere Island which is a very remote place in the Canadian Arctic where wolves have not had much contact with humans since the longest time (yet wolves were supposedly domesticated far prior to that which should mean that the wolves would have any genetic/instinctual knowledge regarding human impacts on their litters).
On Ellesmere, wolves allow humans very near their pups and even bring their pups close to human settlements and do not evade human contact with the pups (while observing healthy caution).
My assumption is that a species that would have experienced pup-snatching by humans throughout longer periods of time and rather frequently, would exhibit instinctively different (more protective, evasive, aggressive) attitudes in situations where humans came into contact with their offspring.
However, I am not composing this article to debunk or to support the two hypotheses.
I have developed two theories of my own which I wish to propose.
One of them concerns hunting strategies and the other theory concerns mating strategies.
Cooperative Hunting
While not widespread and rarely lasting, there have been observations of wolves and other canids cooperating outside of their species limits (interspecific cooperation) in hunting down prey or of using other species in order to enhance their own hunting success.
For example, recently there have been some photographs published which were captured by a Finnish photographer illustrating ‘an unusual friendship between a wolf and a bear’ who appeared to be hunting together and feeding together and resting together.
Usually, bears and wolves scavenge on one another’s kills (with bears having the upper hand and usurping the carcass).
It was hypothesized that these particular animals ‘striking up a friendship’ were young and lacking life skills (possibly dispersing, looking for their own territory and mate, unfamiliar with the surroundings and, with respect to wolf, less capable of providing for itself without the help of a larger pack).
Therefore they might have found in each other a hunting partner ensuring higher success rates together during this perhaps vulnerable stage in their lives.
Wolves and bears have been known to sometimes hunt together on other occasions, as well, although, most often, the cooperative kill does not result in a shared meal (nor resting together, travelling together) because one party snatches the kill from the other and the cooperation is over.
While wolves and bears do not have dissimilar hunting strategies, there is evidence that canids are capable of cooperating with species whose hunting strategies are different from their own – to a mutual benefit.
For example, coyotes and badgers sometimes hunt together.
They hunt ground-dwelling animals.
The badger intrudes in the burrow to flush the animal out where it can be chased by the coyote.
Badgers are not so good at running but they can dig.
While the prey is aboveground, coyote takes care of the chase.
If the prey tries to find escape underground, the badger steps in and digs it out again.
Thus it would appear that these animals (coyote and badger) have observed each other’s differing hunting strategies and managed to figure out successful cooperation.
Similarly, foxes (also canids) follow badgers to find the best foraging grounds or to benefit from rodents flushed out by badgers during their foraging activities although this has not been studied extensively providing irrefutable evidence.
Also, for example, Ethiopian wolves (Venkatamaran, V.V. et al., 2015) hunt rodents amidst foraging (grazing) gelada monkeys.
While this is not an example of cooperative hunting because the geladas do not hunt rodents and they do not benefit from the interaction (although the presence of a solitary Ethiopian wolf could perhaps provide additional security against other predators), it indicates to the ability of the canids to observe other species’ behaviour and to benefit from it (geladas either flush out the rodents as they graze on grassy tussocks or the presence of geladas and their activity ‘confuse’ the rodents through visual and auditory stimuli that makes it more difficult for the rodents to effectively watch out for predators).
The Ethiopian wolves even adapt their own behaviour (less running, more stalking, slow, flowing motions) in order not to spook the geladas (young geladas can fall prey to canids like dogs and therefore the Ethiopian wolves have supposedly habituated them to their presence).
Upon having read these examples, I have been wondering if this could be applicable to wolves and humans (in which case it would be likely that the wolf initiated the cooperative hunt because the wolf actually benefits more from the tandem).
Wolves are good at chasing and ”herding” the prey and they can single out the most vulnerable individual which is then easier killed.
Meanwhile, it is dangerous for the wolf to actually make the kill – to make the physical contact which can end in injury and even death of the wolf.
This results, for example, in reduced rates of participation in certain, increasingly dangerous hunting stages by the wolf group members (it is safer to approach, watch, attack groups than to attack-individual, capture, kill, see, e.g., MacNulty, D.R. et al., 2007).
My hypothesis is that if the wolves observed the human capability of killing the same prey species ”remotely” (with the use of spear or arrows) and thus figured out that humans could assist them during the most dangerous stage of hunt (making contact, biting into throat, i.e., attack-individual, capture, kill), wolves might have attempted to herd prey individuals toward humans in order for the humans to make kills and to later scavenge from these kills.
This would be especially important for lone wolves, namely, wolves during their dispersal (or older individuals, individuals who have lost their packs etc.) who are less capable of taking down large prey on their own.
It would be also beneficial for humans because wolves could wear the prey down and chase them toward the hunter etc.
However, wolves tend to select weak individuals and domestication might have enabled the humans to command wolves which individuals should be separated from the herd (although there is still much debate regarding human hunting vs. scavenging lifestyle during Plio-Pleistocene (e.g., Domínguez-Rodrigo, M., 2002) – perhaps humans (unlike nowadays) did not mind foraging on individuals that are ‘less than in prime’ at all.
If humans, in fact, shifted from scavening toward hunting (for example, while moving northward during their range expansion where reliance on meat was heavier than in the regions with more abundant vegetation – or during glaciations), such cooperation might have enabled them to survive.
Wolves can be very good at figuring out other species’ strategies as is also shown in research concerning wolves ambushing beavers (Gable, T.D. et al., 2021).
Wolves are apparently highly knowledgeable as to where beavers will move along their short inland trails and wait nearby beaver activity sites – such as gnawed trees – and they take into account the fact that beavers have poor eyesight and a good sense of smell which is why wolves hide in places considering wind direction and beaver movement so that the beaver noticed the wolf only when the beaver had passed the wolf already and it were too late.
This proves to what extent wolves have ‘studied’ beaver behaviour and habits.
It means that wolves are aware of beavers’ sensory capacities, of beavers’ customary escape route for water, of beavers’ frequented activity sites etc.
Thereby, what if the domestication process was initiated on hunting grounds rather than in human settlements and what if it was initiated by wolves, not by humans and not in order to scavenge but to hunt cooperatively?
Is it not more likely that humans got interested in having wolves around if they had evidence on wolf benefits in hunting capacity?
Especially, where humans wiped out other large predators who competed with their kill rate and where humans did not have permanent settlements that needed to be guarded (although, of course, transient camps and the life of migrating human individuals could also be protected by wolves but there is also the consideration that keeping a dog (a wolf) can, in fact, attract other wolves).
Additionally, I have been intrigued by a research concerning wolf and dog genetics and dog ancestry traced back to the beginnings of domestication (Bergström, A. et al., 2022).
The ancient wolf populations, during Pleistocene, do not show great rates of subpopulation division (subpopulations are genetically distinctive and they are usually formed when migration is limited which results in isolated populations that develop their own genetic lineage).
This suggests that these populations were rather well interconnected (wolves could travel and with wolves, genes could travel – a more homogeneous genetic make-up is observed).
In the publication, it was also discussed that habitat fragmentation and disconnectedness are, largely, a ‘recent’ issue (over the last centuries – due to human encroachment on wolf habitat).
However, ‘there is some evidence for increasing differentiation already during the last 20,000 years’ (Anders Bergstrom et al., 2022).
The last quote indicates that perhaps some natural barriers or even human presence began introducing obstacles to wolf migration which resulted in more isolated subpopulations that acquired their own distinctive gene pattern.
The proposed dates for wolf domestication lie between before 40 and 15 000 years ago.
If this happened, indeed, during a time when migration became more complicated and encounters with humans more frequent, this could imply that wolves perhaps had to travel larger distances to connect subpopulations and to find mates (when the local population density was too high or when the particular wolf individual was more prone to dispersing far and mating into other subpopulations).
During such dispersal, the wolf could have possibly traversed difficult habitats and, as mentioned before, met humans.
This corroborates the lone wolf (solitary disperser) – prone to cooperation with other species narrative where a migrating wolf would be more inclined to hunt cooperatively (with humans) because it is more difficult to hunt on its own.
Mate Finding
However, the disconnected habitat and potentially frequent encounters with humans made me think about mating and territory-establishment strategies.
If humans at some point had already domesticated wolves, then these dispersing wolves might have been attracted to the single individuals that followed humans – especially, while travelling through a no-wolf country where mate resources are scarce.
What if wolves who were ‘trapped’ due to habitat disconnectedness, developed a strategy of ensuring mating chances by joining human communities?
Similarly, in areas of high wolf density, wolves might have used humans as a shield toward other wolves because, under human ‘protection’, they could hunt in other wolves’ territories while also keeping their mate (with the humans as their extended social group) and potentially reproducing.
On one hand, there could have been wolves that joined human-dog communities in order to mate with the dogs while dispersing through landscapes where other wolves cannot be found easily.
On the other hand, wolves might have acquired a nomadic lifestyle and migrating with the human groups through other wolves’ ranges without the necessity to maintain a fixed territory but with the opportunity to hunt on other wolves’ territories and to have a mate.
Wolves who live with humans do not get to create home ranges similar to their wild counterparts but they get to mate and to produce litters.
Thus, wolves who were limited from natural reproductive strategies, might select for human proximity that ensured a certain type of social group and protection / increased foraging success with additional access to mates (other domesticated wolves) – without the dangers associated with establishing territories in overpopulated areas or crossing impossible terrains.
***
These are my two theories that reflect on why wolves may have selected humans as their hunting partners or their social group within which mating could take place.
It is possible that dogs (wolves) were domesticated several times during our common history (Frantz, L.A.F. et al., 2016) and I do not find it inconceivable that there might have been several ways how we came by our best friends and that perhaps we do not have to single out one hypothesis but many mechanisms were at work for humans to learn that wolves were valuable to them.
References
Bergström, A., Stanton, D.W.G., Taron, U.H. et al. Grey wolf genomic history reveals a dual ancestry of dogs. Nature 607, 313–320 (2022). https://doi.org/10.1038/s41586-022-04824-9
Domínguez-Rodrigo, Manuel. “Hunting and Scavenging by Early Humans: The State of the Debate.” Journal of World Prehistory 16, no. 1 (2002): 1–54. http://www.jstor.org/stable/25801183.
Gable, T.D. et al., Wolves choose ambushing locations to counter and capitalize on the sensory abilities of their prey, Behavioral Ecology, Volume 32, Issue 2, March/April 2021, Pages 339–348, https://doi.org/10.1093/beheco/araa147
Laurent A. F. Frantz et al. Genomic and archaeological evidence suggest a dual origin of domestic dogs.Science352,1228-1231(2016). DOI:10.1126/science.aaf3161
MacNulty, D.R. et al., A Proposed Ethogram of Large-Carnivore Predatory Behavior, Exemplified by the Wolf, Journal of Mammalogy, Volume 88, Issue 3, June 2007, Pages 595–605, https://doi.org/10.1644/06-MAMM-A-119R1.1
Mech, L. & Janssens, Luc. (2021). An assessment of current wolf Canis lupus domestication hypotheses based on wolf ecology and behaviour. Mammal Review. 52. 10.1111/mam.12273.
National Geographic. Opinion: We Didn’t Domesticate Dogs. They Domesticated Us, Brian Hare, March 3, 2013, https://www.nationalgeographic.com/animals/article/130302-dog-domestic-evolution-science-wolf-wolves-human
National Geographic. Why this coyote and badger ‘friendship’ has excited scientists, Christine dell’Amore, February 5, 2020, https://www.nationalgeographic.com/animals/article/coyote-badger-video-behavior-friends
Vivek V. Venkataraman, Jeffrey T. Kerby, Nga Nguyen, Zelealem Tefera Ashenafi, Peter J. Fashing, Solitary Ethiopian wolves increase predation success on rodents when among grazing gelada monkey herds, Journal of Mammalogy, Volume 96, Issue 1, 15 February 2015, Pages 129–137, https://doi.org/10.1093/jmammal/gyu013
Notes by Ieva 