Think Like the Scientist: Keith Aubry
Meet the Scientist | About the Study

Below is an article from Natural Inquirer that explains Dr. Aubry's work with wolverine populations more fully. Use the links to see an example of developing a testable question (introduction), planning to test your question (method), analyzing your data (results), and explaining it all (discussion).

View There's Snow Place Like Home to see the full article.

Introduction | Method | Results | Discussion

There's Snow Place Like Home

Figure 1: The wolverine is well adapted for living in snowy environments. By looking at the picture, name one adaptation the wolverine has to allow it to live in the snow. Photo courtesy of Keith Aubry.


Figure 2 (above): In the lower 48 States, the wolverine’s current range (1995–2005) is restricted to northern portions of the western mountains. The scientists studied wolverine habitat in these States.


Figure 3: An example of geographic wolverine records placed on a map.






Figure 4a, 4b, and 4c: The historical, recent, and current distribution of wolverines in the northern mountains of the Western United States. Forest Service image.




Figure 5a and 5b: Wolverine distribution and the location of alpine areas and conifer forests. What do you notice about where the wolverines live?

Introduction

Wolverines, the largest terrestrial member of the weasel family, are mammals that are difficult to find (figure 1). Because they live in areas far from humans and human development, therefore, not much is known about these mammals. Wolverines are primarily scavengers, and they sometimes travel great distances in a day in search of food or shelter.

In North America, they are currently found in most of Alaska and Canada, but only in the mountainous northern portion of the lower 48 States (figure 2, below). Wolverines may seek shelter under fallen logs or boulders, and female wolverines give birth to their kits in snow-dens. Neither the current nor historical range of wolverines in the lower 48 States was well known before the work of these scientists.

This was a problem because some groups had petitioned for the wolverine to be listed as an endangered species. One of the reasons the petitions were denied was because no one was certain where wolverines occurred in the United States. The scientists in this study, therefore, wanted to accurately map the wolverines’ range over time and evaluate how climate change might be affecting their range.

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Methods

The scientists gathered information about wolverine trapping and sightings between 1801 and 2005. They also gathered information about wolverines from museums. Each record included geographic information identifying where the wolverines were seen (figure 3).

The scientists divided the records into three time periods—

• 1995–2005 (current)
• 1961–1994 (recent)
• 1801–1961 (historical)

The scientists used computer software to create maps with the data. The scientists also collected information about the type of vegetation in the area. They collected information about climatic (klī ma tik) conditions over time and about the spring snow cover from recent years. The scientists added all this information to the maps to see how particular climatic conditions or spring snow cover compared with the wolverine records.

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Results
The completed maps showed that the range of wolverines shrunk over time, as illustrated by wolverine records from historical to current times (figures 1a, 1b, and 1c).

It was also evident that wolverines depend on particular habitat conditions for survival (figures 2a and 2b).

This study was the first time anyone accurately assessed the range of wolverines over time. The scientists found that wolverines live in areas of the United States where snowpacks remain through the spring period. This is the time when wolverines make their dens.

The scientists also found that most wolverine sightings were in alpine meadows and conifer forests. Alpine meadows are found high in the mountains (figure 5a). Conifer forests are areas with trees that have cones and that typically do not lose their leaves in the fall or winter (figure 5b).

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Discussion
Wolverines have already experienced habitat losses. Discovering that wolverines live near areas that have spring snow cover is important. It is important because as the climate changes and becomes warmer, the snow in these areas will melt earlier in the year.

As the climate in these areas warms, the range of suitable wolverine habitat will change. In addition, the wolverine’s reproduction may be affected. The scientists believe that more research needs to be done to fully understand the potential impact of climate change on wolverine populations.

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