Effects of Wolf Predation

This paper discusses four hypotheses to explain the effects of wolf predation on prey populations of large ungulates. The four proposed hypotheses examined are the predation limiting hypothesis, the predation regulating hypothesis, the predator pit hypothesis, and the stable limit cycle hypothesis. There is much research literature that discusses how these hypotheses can be used to interpret various data sets obtained from field studies.

It was concluded that the predation limiting hypothesis fit most study cases, but that more research is necessary to account for multiple predator – multiple prey The effects of predation can have an enormous impact on the ecological organization and structure of communities. The processes of predation affect virtually every species to some degree or another. Predation can be defined as when members of one species eat (and/or kill) those of another species. The specific type of predation between wolves and large ungulates involves carnivores preying on herbivores.

Predation can have many possible effects on the interrelations of populations. To draw any correlations between the effects of these predator-prey interactions requires studies of a long duration, and tatistical analysis of large data sets representative of the populations as a whole. Predation could limit the prey distribution and decrease abundance. Such limitation may be desirable in the case of pest species, or undesirable to some individuals as with game animals or endangered species. Predation may also act as a major selective force.

The effects of predator prey coevolution can explain many evolutionary adaptations in both predator and prey species. The effects of wolf predation on species of large ungulates have proven to be controversial and elusive. There have been many different odels proposed to describe the processes operating on populations influenced by wolf predation. Some of the proposed mechanisms include the predation limiting hypothesis, the predation regulating hypothesis, the predator pit hypothesis, and the stable limit cycle hypothesis (Boutin 1992).

The purpose of this paper is to assess the empirical data on population dynamics and attempt to determine if one of the four hypotheses is a better model of the effects of wolf predation on ungulate population densities. The predation limiting hypothesis proposes that predation is the primary factor that limits prey density. In this non- equilibrium model recurrent fluctuations occur in the prey population. This implies that the prey population does not return to some particular equilibrium after deviation. The predation limiting hypothesis involves a density independent mechanism.

The mechanism might apply to one prey – one predator systems (Boutin 1992). This hypothesis predicts that losses of prey due to predation will be large enough to Many studies support the hypothesis that predation limits prey density. Bergerud et al. (1983) concluded from their study of the interrelations of wolves and moose in the Pukaskwa National Park that olf predation limited, and may have caused a decline in, the moose population, and that if wolves were eliminated, the moose population would increase until limited by some other regulatory factor, such as food availability.

However, they go on to point out that this upper limit will not be sustainable, but will eventually lead to resource depletion and population decline. Seip (1992) found that high wolf predation on caribou in the Quesnel Lake area resulted in a decline in the population, while low wolf predation in the Wells Gray Provincial Park resulted in a slowly increasing population. Wolf predation at the Quesnel Lake area remained high despite a fifty percent decline in the caribou population, indicating that mortality due to predation was not density-dependent within this range of population densities.

Dale et al. (1994), in their study of wolves and caribou in Gates National Park and Preserve, showed that wolf predation can be an important limiting factor at low caribou population densities, and may have an anti-regulatory effect. They also state that wolf predation may affect the distribution and abundance of caribou populations. Bergerud and Ballard (1988), in their interpretation of the Nelchina caribou herd case history, said that during and immediately following a reduction in the wolf population, calf recruitment increased, which should result in a future caribou population increase.

Gasaway et al. (1983) also indicated that wolf predation can sufficiently increase the rate of mortality in a prey population to prevent the population’s increase. Even though there has been much support of this hypothesis, Boutin (1992) suggests that “there is little doubt that predation is a limiting factor, but in cases where its magnitude has been measured, t is no greater than other factors such as hunting. ” A second hypothesis about the effects of wolf predation is the predation regulating hypothesis, which proposes that predation regulates prey densities around a low-density equilibrium.

This hypothesis fits an equilibrium model, and assumes that following deviation, prey populations return to their pre-existing equilibrium levels. This predator regulating hypothesis proposes that predation is a density-dependent mechanism affecting low to intermediate prey densities, and a density-independent mechanism at high prey densities. Some research supports predation as a regulating mechanism. Messier (1985), in a study of moose near Quebec, Canada, draws the conclusion that wolf-ungulate systems, if regulated naturally, stabilize at low prey and low predator population densities.

In Messier’s (1994) later analysis, based on twenty-seven studies where moose were the dominant prey species of wolves, he determined that wolf predation can be density-dependent at the lower range of moose densities. This result demonstrates that predation is capable of regulating ungulate populations. Even so, according to Boutin (1992) ore studies are necessary, particularly at high moose densities, to determine if predation is regulatory. A third proposal to model the effects of wolf predation on prey populations is the predator pit hypothesis.

This hypothesis is a multiple equilibria model. It proposes that predation regulates prey densities around a low-density equilibrium. The prey population can then escape this regulation once prey densities pass a certain threshold. Once this takes place, the population reaches an upper equilibrium. At this upper equilibrium, the prey population densities re regulated by competition for (and or availability of) food. This predator pit hypothesis assumes that predator losses are density-dependent at low prey densities, but inversely density-dependent at high prey densities.

Van Ballenberghe (1985) states that wolf population regulation is needed when a caribou herd population declines and becomes trapped in a predator pit, wherein predators are able to prevent caribou populations from increasing. The final model that attempts to describe the effects of predation on prey populations is the stable limit cycle hypothesis. This hypothesis proposes that vulnerability of prey to predation depends on past environmental conditions.

According to this theory, individuals of a prey population born under unfavorable conditions are more vulnerable to predation throughout their adult lives than those born under favorable conditions. This model would produce time lags between the proliferation of the predator and the prey populations, in effect generating recurring cycles. Boutin (1992) states that if this hypothesis is correct, the effects of food availability (or the lack of) should be more subtle than outright starvation. Relatively severe inters could have long- term effects by altering growth, production, and vulnerability.

Thompson and Peterson (1988) reported that there are no documented cases of wolf predation imposing a long-term limit on ungulate populations independent of environmental influences. They also point out that summer moose calf mortality was high whether predators were present or not, and that snow conditions during the winter affected the vulnerability of calves to predation. Messier (1994) asserts that snow accumulation during consecutive winters does not create a cumulative impact on the nutritional status of deer and

All of the four proposed theories mentioned above could describe the interrelationships between the predation of wolves and their usual north american prey of large ungulate species. There has been ample evidence presented in the primary research literature to support any one of the four potential models. The predation limiting hypothesis seems to enjoy wide popular support, and seems to most accurately describe most of the trends observed in predator-prey populations. Most researchers seem to think that more specific studies need to be conducted to find an ideal model of the effects of predation.

Bergerud and Ballard (1988) stated “A simple numbers argument regarding prey:predator ratios overlooks the complexities in multi-predator-prey systems that can involve surplus killing, additive predation between predators, enhancement and interference between predator species, switch over between prey species, and a three-fold variation in food consumption rates by wolves. ” Dale et al. (1994) stated that further knowledge of the factors affecting prey switching, such as density-dependent changes in vulnerability within and between prey species, and further knowledge of wolf population response is needed o draw any firm conclusions.

Boutin (1992) also proposed that the full impact of predation has seldom been measured because researchers have concentrated on measuring losses of prey to wolves only. Recently, bear predation on moose calves has been found to be substantial, but there are few studies which examine this phenomenon (Boutin 1992). Messier (1994) also pointed out that grizzly and black bears may be important predators of moose calves during the summer. Seip (1992), too, states that bear predation was a significant cause of adult caribou mortality.

Calculate the price
Make an order in advance and get the best price
Pages (550 words)
$0.00
*Price with a welcome 15% discount applied.
Pro tip: If you want to save more money and pay the lowest price, you need to set a more extended deadline.
We know how difficult it is to be a student these days. That's why our prices are one of the most affordable on the market, and there are no hidden fees.

Instead, we offer bonuses, discounts, and free services to make your experience outstanding.
How it works
Receive a 100% original paper that will pass Turnitin from a top essay writing service
step 1
Upload your instructions
Fill out the order form and provide paper details. You can even attach screenshots or add additional instructions later. If something is not clear or missing, the writer will contact you for clarification.
Pro service tips
How to get the most out of your experience with MyStudyWriters
One writer throughout the entire course
If you like the writer, you can hire them again. Just copy & paste their ID on the order form ("Preferred Writer's ID" field). This way, your vocabulary will be uniform, and the writer will be aware of your needs.
The same paper from different writers
You can order essay or any other work from two different writers to choose the best one or give another version to a friend. This can be done through the add-on "Same paper from another writer."
Copy of sources used by the writer
Our college essay writers work with ScienceDirect and other databases. They can send you articles or materials used in PDF or through screenshots. Just tick the "Copy of sources" field on the order form.
Testimonials
See why 20k+ students have chosen us as their sole writing assistance provider
Check out the latest reviews and opinions submitted by real customers worldwide and make an informed decision.
ACC543MANAGERIALACCOUNTINGANDLEGALASPECTS
excellent
Customer 452773, January 25th, 2024
Management
Love this writer!!! Great work
Customer 452597, April 5th, 2021
Business and administrative studies
Excellent work ,always done early
Customer 452773, February 21st, 2023
Human Resources Management (HRM)
excellent job
Customer 452773, July 17th, 2023
Business Studies
Thank you very much for a good job done and a quick turn around time.
Customer 452615, March 31st, 2021
Leadership Studies
excellent job as always
Customer 452773, September 2nd, 2023
Nursing
thank you so much
Customer 452749, June 10th, 2021
Business and administrative studies
Excellent job
Customer 452773, March 17th, 2023
Business and administrative studies
great job as always
Customer 452773, February 26th, 2023
Leadership Studies
excellent job
Customer 452773, August 3rd, 2023
business
Thank you for your hard work and help.
Customer 452773, February 13th, 2023
Business and administrative studies
Thank you for your hard work and help
Customer 452773, February 21st, 2023
11,595
Customer reviews in total
96%
Current satisfaction rate
3 pages
Average paper length
37%
Customers referred by a friend
OUR GIFT TO YOU
15% OFF your first order
Use a coupon FIRST15 and enjoy expert help with any task at the most affordable price.
Claim my 15% OFF Order in Chat
Close

Sometimes it is hard to do all the work on your own

Let us help you get a good grade on your paper. Get professional help and free up your time for more important courses. Let us handle your;

  • Dissertations and Thesis
  • Essays
  • All Assignments

  • Research papers
  • Terms Papers
  • Online Classes
Live ChatWhatsApp