bruggeman_noca_pika_poster_2011

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					     Pika Research in the North Cascades
National Park Service Complex in 2009 and 2010
                                      The Pika in the North Cascades
•        The American pika (Photo 1) is a small mammal that lives only in talus patches located in
         habitats ranging from low elevation forests up to high elevation alpine meadows in the North
         Cascades National Park Service Complex.
•        Pikas are considered to be a climate change indicator species because of their
         sensitivity to high temperatures and obligation to talus habitat.
•        Climate change may affect pikas through changes in foraging behavior owing to summer                                                                 Photos 2, 3 & 4. From left to right, examples of talus patches at low (472 m), middle (1,464 m), and
                                                                                                                                                              high (2,118 m) elevations in the North Cascades National Park Service Complex.
         temperature increases, alterations in vegetation across elevations that may affect forage
         availability, and changes in winter snowpack and temperature patterns that               may
         negatively influence survival.                                                                                                                                                 Additional Key Results
                                                                                                                                                         •          Pika abundance in talus patches was negatively correlated with the
                                                                                                                                                                    minimum temperature recorded beneath the talus surface during
                                           Field Methods and Results                                                                                                surveys (Figure 1), suggesting as sub-surface temperatures
•        In summer 2009, surveyors gathered data on pika abundance, habitat                                                                                         increased, pika abundance decreased.
         attributes, and temperature in 115 talus patches contained within 30                          •                                                            Total pika abundance in 1-km2 survey areas was positively
         1-km2 survey areas throughout the North Cascades National Park                                                                                             correlated with elevation (Figure 2) and an interaction between
         Service Complex. Surveyors found pikas in 74% of talus patches and 90%                                                                                     elevation and the proportion of vegetation cover in patches,
         of 1-km2 survey areas, with abundance per survey area ranging from 0 to 101 pikas.                                                                         suggesting higher elevation survey areas and those with more
•        In summer 2010, surveyors revisited 58 of the 115 patches included in 13 of the 30 1-km2                                                                   cover supported more pikas compared to lower elevations. This
         survey areas, and found pikas in 76% of patches and all 13 survey areas, with abundance                                                                    finding may be indicative of higher quality vegetation at higher
         per area ranging from 4 to 106 pikas.                                                                                                                      elevations.
•        During 2009 and 2010, surveyors found pikas in patches ranging in elevation from 351 to       •                                                            The population growth rate in 1-km2 survey areas between 2009
         2,130 m, which spanned the entire range of elevations for patches surveyed.                                                                                and 2010 was negatively correlated with elevation, which is likely
•        Surveyors recorded vegetation cover types within talus patches in a total of 1,932 1-m2 plots                                                              the result of a combination of winter and spring conditions resulting
         in 2009 and 2010. The frequency of occurrence of vegetation cover types varied with                                                                        in later snowmelt that varied with elevation. The growth rate was
         elevation. Bryophytes and lichens occurred most frequently in plots at low and middle                                                                      also positively correlated with the estimated average minimum daily
         elevations, while cushion plants, forbs, graminoids, and shrubs occurred more often at high                                                                temperature during December 2009 through February 2010, which
         elevations (Photos 2, 3 & 4).                                                                                                                              may be attributed to cold stress on pika over-winter survival.
                                    70                                   120                           •                                                            Because pika populations in the North Cascades National Park
                                                        60
                                                                                                               100                                                  Service Complex during 2009 and 2010 were influenced by multiple
                                            Abundance




                                                                                                   Abundance




                                                        50
                                                                                                               80
                                                        40                                                                                                          climate and habitat factors—notably temperature, elevation, and
                                                                                                               60
                                                        30
                                                                                                               40
                                                                                                                                                                    resource availability—the potential exists for pikas to be adversely
                                                        20
                                                        10                                                     20                                                   affected by climate change in future years. While many of these
                                                         0                                                      0                                                   effects could take many decades to manifest themselves,
                                                             30   40   50    60     70   80   90                     0   500    1000    1500   2000    2500
                                                                                                                                                                    especially for pika populations at higher elevations, changes may
                                                                       Temperature (F)                                           Elevation
Photo 1. A pika in a low elevation talus         Figure 1. The negative correlation between pika                Figure 2. The positive correlation between
                                                                                                                                                                    become apparent in lower elevation populations on shorter time
patch in the North Cascades National             abundance in talus patches and the minimum                     total pika abundance in 1-km2 survey areas          scales.
Park Service Complex                             recorded sub-surface temperature (ºF).                         and elevation (meters).

                                                                  Jason E. Bruggeman1, Roger Christophersen2, Regina Rochefort2, Robert Kuntz2 , and Rachel Richardson1
      1--Beartooth Wildlife Research, LLC, Farmington, MN; 2--National Park Service, North Cascades National Park Service Complex, Sedro-Woolley, WA. Funding for the study was provided by Seattle City Light’s Wildlife Research Program.

				
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