How can I figure out the territorial needs for my Werewolves?

Question

There are lots of different creatures that are loosely based on wolves. The most prominent one is probably the Werewolf, a mix of a human and a wolf. But there are also others, such as Dire Wolves or Wargs.

The problem is How much territory of which kind would I need for a pack of Werewolves/Wargs/Dire Wolves/...?

I am looking for a way to calculate the territorial needs of different packs by comparing each individual to an average gray wolf and then looking at the food and space requirements of the new numbers.

For example, suppose I am using the following numbers for my versions of these creatures:

• An adult Werewolf, when compared to an adult gray wolf:
  • eats twice as much
  • moves twice as fast

This is a simple version at first glance. Every Werewolf is equal to two gray wolves because it's two times as fast and can, therefore, cross two times the distance a gray wolf can while at the same time needing two times as much food. Catching the prey should be a bit easier because it's faster, so I will ignore this fact. Looking at Wikipedia should show me the average gray wolf pack consists of x members, so it should be possible use x/2 Werewolves with the same territory... Right?

Taking a look at Wikipedia:

Territory size depends largely on the amount of prey available

and

The core of their territory is on average 35 km2 (14 sq mi), in which they spend 50% of their time.

but also

The smallest territory on record [...] occupied an estimated 33 km2 (13 sq mi), while the largest was [...] encompassing a 6,272 km2 (2,422 sq mi) area.

That's quite a big difference... And the problem is

The gray wolf is a habitat generalist, and can occur in deserts, grasslands, forests and arctic tundras.

It seems to me that I could just use the core and postulate that this is probably in a forest or grassland as the average habitat, but I am not sure.

The average pack consists of a family of 5–11 animals [...], or sometimes two or three such families, with exceptionally large packs consisting of up to 42 wolves being known.

Again, this doesn't really give me a lot of information as there is a lot of variance here. But basically, I think I could just use a territory of 35 km² and probably 3 to 6 Werewolves (one to 3 of them being juveniles and 1 yearling for the largest pack). But what if I wanted to have 12 Werewolves in my pack? Could I just scale that up and say that it's probably somewhere between 70 km² and 140 km² of forest land? Or would prey not be able to recover from, well, being preyed on? My prey needs some time to have offspring that will be able to feed my pack, so I can't just kill all of them.

All of this seems awfully rough, even by my standards (and I am handwaving that Werewolves can exist). I'd prefer to have a better grasp on the subject to not feel like I am just pulling numbers out of thin air. (Rough estimates are okay, but it should be better than "probably more than 10 km² and there are probably more than 2 Werewolves".)

But what if I say that my Werewolf does not move twice as fast, but instead is only equally fast?

Now, this Werewolf can't move so fast and my pack needs to find two times the amount of prey in the same area that gray wolves have at their disposal. Would this change anything at my calculation, for example, because there is just not enough prey in this region? I have no idea how to get this information.

For simplicities sake, I only want to look at packs consisting of one species.

Imagine I postulate that Werewolves are equally fast but eat three times as much as gray wolves and my pack consists of 15 Werewolves in a middle European forest:

How can I calculate the territorial needs of my pack?

I'd prefer answers to give resources where I can look up the relevant information of territory, such as "amount of prey animals per km²" and information about what this means for calculating the needs for different packs in different territories, for example by mentioning limiting factors such as "time the wolve-like creatures can stay in one place" or "amount of water that can be found close enough" (The den is usually constructed not more than 500 m (550 yd) away from a water source). The bolded question is supposed to be an example calculation so that it's easier to understand and to make this question less broad. If there is information missing from the physiology it can be inferred from gray wolves.

A good answer will give me the ability to calculate the territorial needs for differently sized packs of different wolf-like species in different climate regions, while exemplarily answering the bolded example.

Answer 1

Climax forest is not the best habitat for wolves, because they're carnivores and it's not the best habitat for their prey. Most prey species, and especially deer and other medium sized solo grazers, prefer "edge habitat", areas where they can access the cover of forest and the good grazing of grasslands. Woodlands on the edge of grasslands with an annual burn cycle, natural or artificial are often the best habitat for these kinds of animal assemblages.

To work out the food requirements of a given lupine species physical size is probably more important than anything else since all mammals have a minimum calorific requirement per kg of body weight, as they get larger this requirement tends to go down so it would be advantageous to compare your species to existing mammals on a mass basis to determine their overall metabolic requirements. Bear in mind, no pun intended, that carnivores need a bit more food due to the fact that they run down prey, thus using more energy to get their calories than herbivores.

There's a bunch of stuff about prey density and hunting success rates etc... that goes into working out the figure but the next important component boil's down to the average sustainable daily calorie density of the space the wolf pack is in. As an example a pack might be able to harvest an average of ten thousand food calories per acre per day year round, (this is a completely arbitrary number purely as an example). This number will change depending on the speed of the hunter relative to the prey, the number of hunters, their ability to co-ordinate, prey reproduction, prey migration and many many other ecological factors. Here's some numbers that may or may not help:

• According to this list depending on location Grey wolves succeed in their hunts something between 5 and 20% of the time, whether werewolves would be this successful is open for debate, one could argue that human thinking helps with hunting or that the civilised instincts of humans might blunt the hunting drive of the pack.

• Having done some irritatingly unsuccessful research it looks, from this data, like reasonably wild grasslands have something on the order of 16,000kgkm^-2 of meat on the hoof available to hunting carnivores.

• Wolves apparently need about 1 to 1.5kg of meat per pack member per day.
• According to episode one of the documentary Wild Mississippi 8-10 wolves need at least one substantial kill, like an adult deer, every 2 days to get through the winter.

I'd love to run the numbers for you but you'll need to work out some prey species percentages to divide that meat mass into before that's possible so the size distribution of kills can be estimated.

To work out the minimum hunting territory of a pack you need to multiply the subsistence calorie rate for an individual by the number of individuals in the pack and divide that total by the calorie rate of the land they're on.

That gives you an estimate of their minimum range, in reality they're likely to have a much larger range. If they retain a human perspective they'll want resource security and thus probably take and hold as much land as possible, in this scenario speed and senses are of the essence; the deciding factor on territory size is being able to detect and intercept intruders not the direct, immediate, needs of the pack.

I'm not sure where you'd get the exact numbers you'll need to use to work this out I'm afraid but hopefully the above frameworks are of some use to you.

Answer 2

It may be worth distinguishing between a home range for these werewolves, and a territory. The former is typically defined as the "habitually used area", whereas the latter is an area which is actively defended against other individuals/groups of the same species. The two may be the same, or the territory only part of the range.

Mitani & Rodman (1979) proposed a "Defensibility index" which described the relationship between the distance traveled in a day, and the area of the home range (https://link.springer.com/article/10.1007/BF00184423 for a more recent assessment of this study). This was for non-human primates, but the essence is probably the same - long day ranges relative to home range area are necessary for territoriality.

Given that home ranges tend to scale according to food supply, if the prey is widely scattered, then home ranges will be large. If the prey are nomadic, so much the worse for territoriality.

Territoriality is only going to happen if there is some reason that the werewolves need to defend their home range - and this is driven, in part, by the population density. If competitor packs are widely dispersed, then territoriality may be uneconomical (cost more in effort than saved in protecting food sources from other packs); alternatively, if packs encounter one another regularly (very high population density), then again the costs of defence would be too high - instead, we would expect packs to defend individual kills, rather than a foraging area (this would also happen if prey are clumped, and clumps of prey are dispersed relative to one another). So making some decision about how many werewolves, and how many packs these are divided into, will highlight whether they are likely to be territorial.

The quoted wikipedia article appears not to make this distinction. There is no way a pack of grey wolves is defending (against other packs) an area in the region of 6,272 km²! As your question states the need to work out the requirements of different packs, I am assuming that these packs will interact, but whether they are "territorial" or "kill-defenders" will change aspects of their behaviour.

If prey density is heterogeneous, then you could have a situation with some resident, territorial packs (particularly if there are patches of fast-renewing resources (small bodied, fast reproducing prey) within these territories) and other packs that are not territorial but either follow migrating prey, or search over large non-defended areas. Werewolves subsisting on ground-hogs isn't particularly glamorous, but you'll have to solve the food-supply problem if you want packs of werewolves defending discrete areas.

Answer 3

It is useful to start with a food pyramid. Here are some data points:

How much do wolves eat?

15. What do wolves eat?

Gray wolves prey primarily on large, hoofed mammals such as white-tailed deer, mule deer, moose, elk, caribou, bison, Dall sheep, musk oxen, and mountain goat. Medium sized mammals, such as beaver and snowshoe hare, can be an important secondary food source. Occasional wolves will prey on birds or small mammals.

Red wolves primarily prey on white-tailed deer, raccoons, rabbits and rodents.

16. How much do wolves eat?

Gray wolves can survive on about 2 1/2 pounds of food per wolf per day, but they require about 5 pounds per wolf per day to reproduce successfully. The most a gray wolf can eat in one sitting is about 22.5 pounds.

Red wolves eat an average of 5 pounds of food per day, but have been known to eat up to 12 pounds in one sitting.

17. How many prey do gray wolves kill per year?

In Minnesota, wolves kill the average equivalent of 15 to 20 adult-sized deer per wolf per year. Given the 1997-98 estimate of 2,450 wolves in Minnesota, that would equal about 36,750 to 49,000 deer killed by wolves. In comparison, from 1995-1999 hunters killed between 32,300 to 78,200 deer each year in Minnesota's wolf range. In addition, several thousand deer are killed during collisions with vehicles each year.

The deer population of Minnesota is roughly 800,000, as of 1997. Thus, it takes roughly 200 deer to support one gray wolf, and given that they tend to operate in packs of 5-6 wolves, it takes roughly 1,000-1,200 deer to support a wolf pack. Multiple wolf packs are necessary to maintain a viable gene pool.

For reference Minnesota has 86,936 square miles, much of it small glacial lakes interspersed with forests and also some mostly non-natural grassy plains in a temperate to quite cool climate.

How much do mountain lion's eat? (link is to a quote from an original source whose link has gone bad).

Mountain lions eat primarily deer throughout their range. If there are no deer, there are few lions. Secondary prey can include bighorn, javelina, and even porcupines. A puma generally kills one deer per week. The lion caches the carcass under a shrub or buries it under leaves, and may return to feed nightly for several days. Pumas in the desert kill more often then those in the mountain woodlands, because the cached carcasses decay faster in the hot desert.

If the kill to total population ratio of deer is similar for mountain lions and wolves, then it takes about 500 deer to support a single mountain lion. They live in solitary environments most of the time, but it still takes many mountain lions to support a viable gene pool.

Horses as food

One of the main food sources for human hunter-gatherers and large predators on the Pontic-Caspian steppe prior to the Bronze Age was horses.

Of course, a horse is much larger than a deer. Adult horses are 850-2000 pounds. An adult white tailed deer usually weighs 90-220 pounds, although they can get to be up to 350 pounds. Thus, a horse has about ten times as much meat as a deer.

Solitary mountain lions are poor horse predators. A dead horse doesn't last long in the wild, and a mountain lion can only eat so much at once. Most of the meat on a dead horse would be wasted by a single mountain lion whose usual weekly meal is a deer.

On the other hand, a pack of twenty wolves that took down 40 horses a year, could probably eat a comparable share of the meat from the horses to what they take from deer prey. This suggests that a herd of about 400 horses could support a single large wolf pack.

Moreover, in reality, the wolves would probably eat some prey other than horses, so a large wolf pack could probably do well managing a somewhat smaller herd of horses, if it also had other prey available.

Smaller Cats

About 80% of songbirds are killed by predators, and that in particular 47% of songbirds are killed by cats (about equal numbers of feral and domesticated cats) (hard copy newspaper clipping source).

Human Hunter-Gatherers

The lowest recorded hunter gatherer density of 2 individuals per 100 $km^2$ reported for the !Kung (Kelly 1995) and the density of 3 individuals per 100 $km^2$ estimated for Middle Paleolithic people (Hassan 1981).

-Source Per Sjödin, Agnès E Sjöstrand, Mattias Jakobsson and Michael G B Blum, "Resequencing data provide no evidence for a human bottleneck in Africa during the penultimate glacial period" Mol Biol Evol (2012) doi: 10.1093/molbev/mss061.

There are about 2000 Lebbo hunter-gatherers in Southeast Asia, who occupy on the order of 2500 $km^2$ of territory, which is about 80 per 100 $km^2$ in this much more abundant environment.

Population density (and hence a werewolf's territory requirement) is very much a function of vegetation abundance and climate.

Neanderthals and Homo Erectus

The best estimates of peak Neanderthal population are about 70,000 (census population, not effective population). Their geographic range is shown here.

Neanderthals were outnumbered 10:1 by the modern human hunter-gatherers that immediately followed them in residing at the same locations in Europe where adjacent layers are present.

I've estimated Homo Erectus populations in Eurasia before and concluded that the size of the geographic range of Homo Erectus in Asia (and by Asia in this context I mean to the east of India) was on the same order of magnitude as the size of the geographic range of the Neanderthals, but the census population size of Homo Erectus may have been on the order of 7,000 to 35,000.

Answer 4

I am reading into your quotes that though the core area for wolves is almost never under 35 km$^2$, it might be much larger. Let's take those 35 km$^2$. Now, your, say, direwolves move $x$ times faster. Imagine they move randomly. They would be able to cover $x$ times as much in any direction, this translates into $x^2$ larger territory.

As for werevolves needing more food: you might need to check activity or majorly bump their strength compared to a "normal" wolf. It might be that poor licantropes need to hunt all the time. And I am unsure if wolves do not hunt/search for food the majority of time anyway. If so, werewolves starve and die out. The only saver is: they are stronger than wolves. Than they can attack larger prey. Still, the question of sustainability remains.

Answer 5

There are some detailed studies about wolves' territorial size and behaviour from Poland which is well representative of a European forest setting, cf. Habitat variables associated with wolf (Canis lupus) distribution and abundance and Territory size of wolves (Canis lupus) linking local and Holarctic-scale patterns.

On the one hand, they found that the size of territory is independent of pack size for 3-8 wolves averaging 201 km² with core areas ranging from 14 to 78 km².

Home ranges of individual wolves from the same pack varied with season as well as the age, sex, and reproductive status of the wolf. ... latitude and prey biomass were essential factors shaping the biogeographic variation in wolf territory size. Territories increased with latitude and declined with growing biomass of prey.

In principal, the further north the pack lives the more likely it has to follow its nomadic prey. The further south and less likely the prey migrates, the smaller the territory hast to be. They also found that wolves are less likely to attack livestock when living in dense forest areas as compared with ares with little forestation.

Thus, in a European forest area with enough deer and small prey to support your pack, your werewolves would have little need to wander with their prey and abundant food sources to provide for their pack, controlling 150-200 km² of total territory and 35 km² of core territory for upbringing of the pups would suffice for their sustainable support.