There are plenty of studies dedicated to analyzing wolf diet and even useful reviews (e.g., Newsome, T.M. et al., 2016) that are often aimed at determining the predominant prey resource in the entire species or in particular populations as well as to evaluate the environmental impact (prey population regulation) and/or the risk of wildlife-livestock conflict.
There are also some studies (e.g., Freund, D.R. et al., 2023; Homkes, A.T. et al., 2020; Barton, B. et al., 2019; Wiebe, N. et al., 2009) that analyze alternative prey resources (resources that can normally do not constitute the bulk diet and might be low in frequency of occurrence but that might be of importance during specific seasons or life history stages, e.g., dispersal, puphood etc.).
I have been wondering whether an individual wolf’s diet might depend on the individual’s age and experience (also outside of the pup stage when pups can forage on available items (e.g., rodents, berries) in the vicinity of the den or rendevouz site which serves as an exercise in hunting skills as well as agility and probably a method to dispel boredom while waiting for the return of adults).
While age and experience are correlated, I stated them as separate factors because experience can be gained not only during growing up and learning from the family but also through other channels, e.g., dispersal, interactions with other individuals whose experience is different, settling in habitats that are different from natal habitat (here, lack of experience might be a factor although later the addition of new experience to the skills acquired in the natal pack might result in an overall greater experience and a vaster range of foraging strategies).
I recognize the difficulty in tracking individual (radio-collared) wolves and acquiring their individual scats as well as providing a large enough sample size in each age and life experience group for statistical analysis.
Still, it might be interesting to study:
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Whether one-year-old vs. two-year-old subordinates have different foraging strategies during summer when the pack tends to split up foraging individually or in smaller groups.
Namely, whether after the winter period of learning the hunting basics from the parents, young wolves show increasingly efficient and diverse forage acquisition strategies as they grow older (in groups that include two-year-old subordinates in addition to yearlings although difference between yearlings and adults might also be studied; however, it would be confounded by the need to provision for the pups which probably determines the breeding adult foraging patterns).
Alternative prey might be a more efficient measure than main prey (although the proficiency at acquiring main prey should also increase overtime reducing the abundance of alternative prey and increasing the abundance of main prey as the individual becomes more skillful hunting on their own).
Differences in abundance might indicate at increasing skill of catching the prey (or foraging other resources such as berries).
Differences in the range of food resources might indicate at flexibility and diversifying of one’s diet by learning to include a great number of different items in it.
For example, two-year-olds might have learned to forage on a greater number of different items and to collect them in larger amounts at a time (more efficient foraging) while, at the same time, the predominant prey might also become more prominent in the diet (due to increasing skills of acquiring it on one’s own or in small groups during the summer period).
I suppose that such differences would be mainly revealed if individual scats could be analyzed because, for example, in the study by Barton, B. et al., 2019, one scat of one individual contained parts of what would have constituted 181 grasshoppers while other scats of the same individual contained no grasshopper parts.
If this scat had not been gathered, the overall analysis of the diet of the individual would perhaps not even include grasshoppers as a diet resource.
Apparently these grasshoppers had been consumed over a brief period of time (possibly one night).
Thus, for example, if young wolves discovered that grasshoppers could be caught and includes them in their diet, the number of grasshoppers might increase in the scats over time but altogether the grasshoppers might show up in few scats that are easily missed in the field.
Alternatively, a yearling might learn to catch grasshoppers but make little use of them in the first year of life while in the second year of life the same yearling might suffer lower large prey availability and they might return to the use of grasshoppers already being more efficient at catching them than individuals with no prior experience.
Thus, it might make sense not only to compare diet between yearlings and two-year-olds but between individuals as yearlings and two-year-olds (however, it would be impossible to predict if the yearling would stay in their natal range as a two-year old during summer).
Regardless, if yearlings alone could be studied, it would be interesting to see if they picked up food habits on their own (resources that do not show up in related adults’ diet).
Also, it would be interesting to see if yearlings that showed a greater foraging efficiency (a greater number or frequency of alternative prey in scats) or a greater dietary diversity would be more successful during dispersal (this could be determined by, e.g., body condition pre-dispersal vs. post-dispersal or by comparing diet niche breadth between diversely foraging yearlings back on their natal range vs. yearlings that preyed only on few items and then analyzing their rates of establishing territories or any other (relevant) quantifiable measure of success.
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With respect to experience, it might be interesting to study whether an individual diet differs pre-dispersal and post-dispersal and whether individuals who have travelled for longer and/or further and/or have had crossed habitats that are very different from natal habitat, attest to a greater efficiency or dietary niche breadth after they have settled in the new territory.
Also, the diet of the whole pack might be compared between packs that are led by breeders who had a more lengthy / varied dispersing experience vs. breeders who did not disperse at all or did not disperse long/ far, or only travelled through habitats very similar to natal range.
Similarly, diet of the entire family might be studied in wolves that have paired up with individuals from very different natal family living (foraging) conditions.
It would be curious to see, moreover, whether pack’s diet changed after a replacement of a breeder (on occasion the pack itself did not dissolve but simply acquired a new dominant male or female) or with adoption of new unrelated family members (the latter case being rare and probably hard to study because the additions to pack count often become apparent in the winter or in the following year during the tracking effort or trail camera material review).
It is possible that such differences might be significant during periods of extreme weather or food scarcity or sudden loss of pack members and other trying circumstances where survival depends on flexibility, ability to adapt and to persist on what is not entirely ‘traditional’.
Of course, the impacts also depend on the post-dispersal habitat.
Even if individuals had acquired diverse foraging experience, they might not be able to apply it in areas without the particular food resources.
However, the adaptivity itself and the cognitive advancement gained through applying different skills and engaging with novel challenges might serve as important benefits.
The individual might not be able to use the same skills but they might be more creative in figuring out what else could be edible and forageable in times of hardship as well as methods to acquire this food.
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It might be interesting to study whether the family diet changes over time as the breeding pair becomes more and more established in their territory and familiar with their resources.
In this case, it is possible that the diet might even become less diverse as the wolves learn to locate and kill their main prey more efficiently with every year that has been spent in their new home.
However, curious summer food tendencies might show up where long-term residents learn to provide in abundance during the typical low-availability periods (e.g., late summer – autumn).
Notes by Ieva 