So here are some factors that explain this difficulty:
1. Wolf cubs are kept in a well-hidden place during the first few months of their lives.
2. Subadults may travel on "excursions" before their final departure ; they don't stay with their pack all the time.
3. Wolf movements aren't carried out in a predictable and established way.
For all those reasons, before the invention of thermal vision which permitted a better knowledge, behavioral studies of wolves were sometimes done in anthropized environments (1), such as zoos. The wolves present in zoos were born there and have always lived in captivity. Obviously this can modify certain behaviors and soften certain instincts. These wolves live in an enclosure representing barely 1/100th of their natural territory, are fed, do not hunt (or sometimes birds or rodents slipping into the park) and live all their life with the same individuals, from which they cannot move away in case of conflicts.
In anthropized areas, there are more conflicts (potentially serious and requiring human intervention, possible separation) and mortality. This can easily be explained by the impossibility for a wolf to escape from its fellow at any time. This particular issue leads to pressure, harassment and even potentially fatal attacks. In the wild, not only can subadults go on excursions, leaving the pack for a few hours/days, but they can also leave the pack permanently, when conflicts become more frequent (sexual maturity, lack of food resources, reproduction etc.). They can also be asked to leave, so there's always a possibility to limit conflicts. We can also mention the fact that a natural pack will not be composed of the same members all its life, since the young individuals will leave and that eventual changes may occur in the breeding pair (replacement, death). A pack is unique, each one has its own functioning, communication codes, organization and take its own decisions. The situation can change each year, the composition of the pack will vary, as the number of individuals, sexes, personalities/characters, throughout the life of the pack.
In a zoo, the parents will stay with their offspring all their life, without any of them being able to leave. As soon as hormones come into play or when an individual is weaker or introverted, conflicts can occur. The breeding male is often castrated (more rarely the female is sterilized due to a more complicated and potentially more problematic surgical procedure) or take birth control pills. Zoos often have no space available and wolf isn't easy to relocate. In fact, it's impossible to introduce a wolf with other foreign individuals into an existing pack. Then it's necessary to find a place where a single individual (preferably of the opposite sex) is waiting for him, in order to eventually form a couple. And even then, the chances of success are not guaranteed. Apollo, before having Daphne, experienced life with 3 different females, with whom, unfortunately, it didn't worked well. That male was kind of "bossy", preventing the female from accessing the food, terrifying her to the point that one of them tried to climb the fences ! As is the case with humans, wolf couples may be formed by feeling, taking into account the personality and the character (type A/type B) of both of them to form of balance. So replacing a wolf who's in serious conflict with its pack is very complicated. We don't want to lie about what sometimes happens in zoos : some individuals are removed as the staff doesn't have any other option. Wolf, as a predator, with his instincts, is a difficult animal to handle with, especially in terms of numbers and the conflicts that logically occur. It's easier to manage deer or any prey species. However, during the reproduction period, the presence of several males can lead to conflicts among them too.
When studying behavior in an anthropized environment, it's important never drawing definitive or overly clear-cut conclusions. Behaviors must be put into context and not systematically transposed to those of wild wolves, in all circumstances. As soon as we understand that fact, which is now common for more than a decade, we can observe, film, interpret, understand, but without necessarily applying to the wild all the behaviors seen in anthropized environments.
We've to be vigilant with the observation made during conflicts, taking into account the fact that, without the possibility of escaping from fellow creatures, the consequences of such situations could potentially be more problematic or serious than in the wild. It's not uncommon to see, in an anthropized or closed environment, what we call "sufferers", even among fish in an aquarium. The shyest, weakest, or most recently arrived individual can be targeted, deprived of food, physically abused and possibly killed. Captivity also leads to changes in sexual dynamics when there are several mature males in the pack. in contrast to the natural environment, where only the breeding male mates, in anthropized environments, according to Rabb and colleagues, the other males would be more sexually active than the breeding male, who would let it go. They even found that once the breeding male died, its substitute also saw his sexual activity drop significantly, whereas it had been more intense until then.
In an anthropized environment, this forced and constant proximity, which is the basis of conflicts, is also responsible for significant changes in roles and behaviors. This is particularly true in the area of the famous domination/submission theory. This point has been the source of misinterpretations in the dog world, transposing the extreme relationships observed in anthropized wolves into rules to apply in dog training. Many dogs have suffered the consequences of this, resulting in a form of abuse (dog knocked down on its back to "show" submission, who is in charge; an aberration today but still applied by some bad dog trainers). The notion of dominant/submissive has proven to be false in the lupine world, David Mech has come back on this theory thanks to more than 50 years of study in nature. A pack is nothing else than a family, led by 2 parents who educate their cubs, passing them a number of whims at the beginning and then putting them back in place in a stronger way as soon as the young grow up, especially when the size is almost identical. This phase corresponds, in humans, to pre-adolescence and adolescence.
In nature, no individual is constantly subjected, mistreated or tyrannical, no one traumatizes or suffers for months or years ! Why ? Simply because any individual who no longer finds its place in the pack, being too "weak" or, on the opposite, seeking confrontation a bit too much (which often happens in the period of sexual maturity, hormones naturally influencing behaviors), will be chased away or will decide to leave by itself. A wolf will never stay all its life in a pack where he lives in permanent conflict Let's remember, by the way, that the canid, deep down and through its behaviors (mimics, postures etc.), continuously transmits the non-conflict ! The only canids that will subjected to that kind of issues are some domestic dogs, condemned to suffer human errors, doesn't know/understand them and imposes a life opposite to their needs. This is unfortunately a well-known fact, humans having a tendency to anthropomorphize (1).
Studying wolf behavior in an anthropized environment is possible. It's better to find a zoo that limits contact with humans to a minimum. The following crucial points should be kept in mind: the animals are fed, live in a closed environment, highly inferior to their natural territory and cannot escape or leave the pack ! So it's recommended to have to have a knowledge of the canine and lupine environments, in order to avoid any erroneous transpositions.
Dictionary
(1) Anthropized environments : modified by the human presence.
(2) Anthropomorphism: tendency to attribute human reactions to animals.