Monday, April 20, 2015

Exploring Badgers with Dr. Jessie Quinn

We're excited to host Dr. Jessie Quinn of Great Ecology for our next Discover Nature lecture on Badgers!

American badger (Taxidea taxus), photo by 
Oregon Department of Fish and Wildlife
Digging Dynamos: 
Badgers of Coastal California
Friday, May 1st, 2015 
7pm lecture, no reservations necessary
Free, with donations greatly appreciated
Click here for more info.

Learn about the mysterious and charismatic American Badger as Dr. Quinn shares her 4 years of work with UC Davis studying badger ecology and population distribution across California. 

We hope you'll join us for her lecture on May 1st! 

In the meantime, brush up on your badger knowledge by reading our latest blog post below. Responses by Dr. Jessie Quinn.
European badger (Meles meles)
1) What is your background and how did you get involved studying badgers?  

My background is in wildlife ecology, which actually stemmed from a love of the outdoors, and from a hobby of birdwatching I developed as an undergraduate at UC Santa Barbara. I spent several years after college working on bird projects for various agencies. I eventually decided to pursue graduate studies at UC Davis in a lab with two potential projects I could work on: one involving invasive black rat impacts on native bird and small mammal populations on the Channel Islands, and another investigating black rat predation on songbird nests in riparian forests in the Central Valley. I worked a little on both of those until an opportunity came along to develop a project investigating the invasive Small Indian mongoose in Puerto Rico.  That project focused on a number of potential predators of the endangered Puerto Rican Parrot, and mongooses in particular as both a parrot predator, and as a vector and reservoir of rabies.  So, I ended up doing my M.S. research on mongoose spatial and social behavior in the context of management of those issues.  I found working with those feisty little carnivores interesting, so I looked toward planning a Ph.D. project on mongooses or a similar species at UCD.  My M.S. advisor was returning to her native Australia, so I found a new advisor in Dr. Rosie Woodroffe, an internationally recognized expert on European badgers in the context of bovine tuberculosis management in the U.K.  She was interested in the conservation of California carnivores, and asked me if anyone had done anything on American badgers.  It turned out that the California Department of Fish and Wildlife (CDFW) had some concern about how California's badgers were doing, but there were hardly any data on their behavior, habitat use, or even range extent. The sparse data included one sighting survey conducted by CDFW in 1986, and before that, a compilation of trapping locations compiled by Joseph Grinnell in the 1920s; and then a telemetry study of 2 badgers for 1 month in the Santa Monica mountains in the 1990s.  Given that sizable knowledge gap, CDFW was willing to fund a study as part of their Resource Assessment Program in partnership with the Wildlife Health Center at UCD assessing the conservation status of the American badger in California, so I decided I'd give it a go.

American badger (Taxidea taxus), photo by 
US Fish and Wildlife Service
2) What are some of the things that make badgers unique and interesting? 
There are so many unique and interesting things about badgers!  They are fossorial carnivores, which is unique, and their phylogeny is very interesting, too… American badgers are the only species in their genus and subfamily.  Same with honey badgers.  The rest of the badgers in Europe and Asia are more closely related to each other, but are also all in different genera.  Of course, their defensive mechanisms—famously their bad attitude—but less famously, their physiology (loose, tough skin, incredible digging ability from their front leg and claw morphology).  Also, they have such an attractive and unique face, which likely evolved to communicate a threat to potential predators.  All a predator needed to see was that little aposematic face filling a burrow hole, coupled with bared teeth and a fierce hissing, and it didn't bother wasting its time pursuing such problematic prey.  

3) Are badgers mostly solitary or do they live in groups?  
American badgers are solitary outside of the breeding season. Only Meles badgers (European and Asian badgers) are truly social and can occupy huge, communal dens for generations.    

4) What traits have helped badgers survive from an evolutionary perspective? Competitively amongst other carnivores their size, badgers occupy a unique ecological niche as a carnivore of the open prairies and deserts that specializes on digging up fossorial rodents.  And of course, the traits I mentioned above (attitude, face, skin characteristics) have long protected them from larger carnivores. Badgers evolved alongside potential predators that included Mountain lions, Grizzly bears and Gray wolves that ranged across most of the Great Plains and western North America before European colonization.  When cornered without a burrow nearby, badgers go on the offensive pretty aggressively.  This deters even those larger predators that don't want to risk the likely injury associated with trying to kill a badger.  And if they do go for the badger, they will find that its skin is so loose, they'll have a hard time keeping a hold of it… when grabbed by the haunches or back, a badger can literally turn around inside its skin and bite the predator in the face.  Badgers' aggressive behavior is necessary because their legs are evolved for digging, not climbing trees or running fast, and they occupy very open habitat without places to hide.

5) What role do badgers play in the ecosystems they call home?  
Badgers move a significant volume of soil on a day to day basis, and thus significantly affect the very structure of the landscape.  Studies in Idaho have documented the significance of badger burrows in the sagebrush-steppe community, and suggest their likely important impacts on soil and ecosystem processes in that habitat.  Additionally, the overturned soil can serve as a colonization site for plants, and the actual burrows are used by numerous other species; including burrowing owls, kit foxes, coyotes, snakes, and ground squirrels.  

6) What is the history of badgers in the Sonoma County area - were they once more prevalent than they are today? If so, are there any steps being taken to encourage population growth?  
Illustration from Popular Science Monthly circa 1891
Sonoma County provides perfect habitat for badgers- oak woodlands, grasslands, and sage scrub.  However, badgers tend to live at low population densities (depending on their prey species distribution), and are somewhat territorial, so that would have limited population size.  But generally, they were probably much more common than they are today.  Badgers were trapped at high densities at the turn of the century for their fur, and because they present a (perhaps perceived) risk to cattle and horses, they were controlled as a pest in rangelands.  Additionally, badgers seem to be especially sensitive to the effects of habitat fragmentation and development.  They don't appear to do well where there are busy highways, and may also be suffer secondary poisoning from ground squirrel, gopher, and coyote control efforts.  Regarding conservation efforts, badgers are listed at the state level as Species of Special Concern.  As of yet, that hasn't meant much in terms of active population management, probably because so little has been known about badger distribution and abundance.  In fact, badgers are still a game species with a designated season, and they can be taken at any time without a permit for depredation.  However, they have to be considered under the CEQA regulatory process (for any state project, or projects that require a state permit that may impact natural resources) due to their listing status, so we do see project proponents that seek to minimize impacts to badgers when they are known to be present at a project site.  However, the challenges that remain for project managers are 1) establishing whether or not badgers are "at" a site, as they move constantly and widely; and 2) figuring out how to avoid badgers when it is hard to predict where they will pop up next.

Dr. Jessie Quinn is a Senior Ecologist at Great Ecology and has over 15 years of experience. She has a strong background studying habitat use, developing species occurrence models, and leading multi-agency studies supporting wildlife management and habitat planning. She develops and conducts habitat and ecological risk assessments, develops standardized methodologies and novel technical tools for quantitative analysis, and oversees fieldwork protocols. Dr. Quinn specializes in Habitat Equivalency Analysis (HEA) for Natural Resource Damage Assessments (NRDA), wetland functional analysis, experimental design and analysis, and inventory and monitoring methods. Dr. Quinn holds a Bachelor’s degree in Ecology from University of California, Santa Barbara, as well as a Master’s degree and Doctorate in Ecology and Conservation from University of California, Davis. - See more at the Great Ecology website.

No comments:

Post a Comment