The Science of Wolves

By Neva Knott

For Wolf Awareness Week, I’m going to post the series of papers I wrote in graduate school for my Conservation Biology course, all on wolves. To produce these papers, I read pretty much everything in the science literature about wolves, and studied the controversy in Oregon–my home at the time. These were written in 2010, but the scientific research is still the most current. What’s changed since is an increase in advocacy. Here’s the first:

Introduction

The current body of research on wolves began in the early 1990s. What is significant about the current body of research, and what sets it apart from what was done before, is that all of it is geared toward understanding wolf reintroduction or re-colonization. Reintroduction programs were conceptualized after the passage of the US Endangered Species Act, which gave protection to the gray wolf. Across the literature, it is clear that the first questions scientists asked were: What are the characteristics of this species? What will it take for this species to thrive? Where are the most habitable places? Along with this much information about the biology of the wolf itself was gathered. From the body of knowledge that now exists, one can now understand a wolf’s habits and needs so that management decisions can be shaped around the ESA policy of protection. As this current body of research has taken shape, Yellowstone National Park, the first site of reintroduction, has emerged as model landscapes. Now the scientific research question has become: What is happening within the ecosystem because wolves are here? Unknown

Image: wiki commons

Literature Review

Wolves: Behavior, Ecology, and Conservation is the wolf-ology compendium. Published in 2003 by University of Chicago Press and editied by L. David Mech and Luigi Biotani, this book covers everything know about wolves as a species to date: social ecology, reproductive, social, and intellectual behavior, carnivorousness, prey relations, population dynamics, physiology, genetics, evolution and taxonomy, interactions with non-prey, and human interaction. As well, Wolves gives scientific correction to some commonly held misbeliefs about wolves such as attacks made on humans, prey relationships, and livestock depredation. Each chapter addresses a specific topic and is authored by an expert for that field. As a collection, these essays provide an in-depth analysis of the risk factors for wolves: persecution, habitat structure and fragmentation, and prey availability. Anyone working with wolves or concerned about wolves should read this book.

Wolves were re-introduced into Yellowstone National Park (YNP) in 1995. Simultaneously, L. David Mech (2005) published “The Challenges and Opportunities of Recovering Wolf Populations” in the journal, Conservation Biology. Just before that, Steven H. Fitts, Edward E. Bangs, and James F. Gore (2004) published “The relationship of wolf recovery to habitat conservation and biodiversity in the northwestern United States” in Landscape and Urban Planning. Taken together, these papers clearly outline what is needed for wolves to survive on the contemporary American landscape. Both papers speak to the needs and functionality of habitat and shape their arguments in favor of wolves as a natural part of the landscape. Mech’s paper looks at reproduction rate and dispersal to consider how wolf habitat needs can be met and managed within the context of human use of land. He is straightforward in his acknowledgement that wolf reintroduction will require some form of wolf control. Fritts, et. al., look not only at habitat, but a availability of prey. As with Mech, they consider where appropriate land might be found, both public and private in ownership, and consider how to control wolves found in the wrong places. These authors conclude simply that, given the availability of land, wolves need only two things to survive: ungulate prey and freedom from human persecution.

Now that wolves have been reintroduced, scientists understand that wolves create a trophic cascade in the ecosystem. Douglas W. Smith, Rolf D. Peterson, and Douglas B. Houston (2003) published “Yellowstone after Wolves” in the journal, BioScience. William J. Ripple and Robert L. Beschta (2004) published “Wolves and the Ecology of Fear: Can Predation Risk Structure Ecosystems?” also in BioScience. Smith, et. al., discuss how the presence of wolves has created balance in animal and plant populations. Ripple and Beschta set the YNP reintroduction into much broader contexts, looking at change over time and at a more complex web of interactions. Both papers clearly support wolf presence as a necessary function of the ecosystem.

Overall, this body of literature gives strong information about the wolf and it’s function as a top predator. A theme has emerged that suggests wolves and humans can and should live on the same landscape.

Knowledge Gaps

Even though the existing literature is rich, there are knowledge gaps. Some of these are identified for the reader in Wolves (2003): dispersal and immigration; effects of prey types and multiple prey; multiple breeding females; role of disease; wolf-human relationships; population assessment; effects on low-density prey; pup survival. Smith, et. al. (2003) in “Yellowstone after Wolves” acknowledge that there is more to know about vegetation further down the trophic cascade. Ripple and Busheta (2004) suggest that a better understanding of elk adaptive responses to wolf presence is needed.

In terms of wolves in my bioregion, there is a knowledge gap in application of the YNP studies as relevant to Oregon. What will be the same here, and what will differ? One clear area of difference is habitat fragmentation, as is addressed in the Oregon Wolf Management Plan. The state’s wilderness is much more parced out and has more roads than does a national park.

Proposed Study

In Oregon, not only are landscape configurations different than in YNP, wolves have taken up residence in an area that is primarily used for ranching. This is another factor that is different than the protection offered in a national park. Therefore, I would propose a study of the relationship between prey availability, habitat fragmentation and livestock predation. This study can draw on what is known about each of these elements separately. A hypothesis can then be formulated about how to avoid killing of livestock by maximizing habitat structure and prey availability.

Conclusion Wolves have not been re-introduced into Oregon, but are dispersing here. All of the literature points to human attitudes as a significant factor in the success of wolves anywhere in America. By utilizing our knowledge of wolf biology and habitat needs, it is possible to create a harmonious existence between the two species that overleaps the main conflict of livestock depredation. As proven in YNP, Oregon’s ecosystem will benefit greatly from these top predators.

Literature Cited

Fritts, Steven H., et. al. 1994. The relationship of wolf recovery to habitat conservation and biodiversity in the northwestern United States.  Landscape and Urban Planning.

Mech, L. David. 1995The Challenge and Opportunity of Recovering Wolf Populations. 1995. Conservation Biology.

Mech, L. David and Biotani, Luigi, eds. Wolves–Behavior, Ecology, and Conservation. 2003. University of Chicago Press.

Ripple, William J., and Beschta, Robert L. 2004. Wolves and the Ecology of Fear: Can Predation Risk Structure Ecosystems?  BioScience. Smith, Douglas, et. al. 2003. Yellowstone after Wolves. 2003. BioScience .

Advertisements

5 thoughts on “The Science of Wolves

  1. Pingback: Wolf Awareness: Oregon Update | The Ecotone Exchange

  2. Pingback: Wolf Awareness: Oregon Update | Wolf Is My Soul

  3. Pingback: The Science of Wolves | animals

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s