the American pika Chris Ray, CU pikas are... ...and... related to rabbits as big as your fist non-hibernating highly vocal habitat specialists herbivorous
highly territorial hay-stackers Ochotona princeps [email protected] Outline Motivation for an individual-based study of climatic stressors Preliminary results from a long-term study in Montana
Preliminary results from a comparative study of MT & CO pikas [email protected] [email protected] Summer heat-stress Grinnell 1917 MacArthur & Wang 1973, 1974 Smith 1974 Hafner 1993, 1994 Hafner & Sullivan 1995 Verts & Carraway 1998 Li et al. 2001 Simpson 2001
Beever et al. 2003, 2010 Winter cold-stress Tapper 1973 Smith 1978 Morrison and Hik 2007 Beever et al. 2010 & in prep. [email protected] Shrinking distribution of the American pika [email protected] 25 historical populations
recorded 1898-1990 (average date = 1933) 6 extinct by 1999 () 10 by 2008 () Extinction rate is rising [email protected] Rising mean minimum elevation of 25 historical pika populations in the Great Basin 2008: 2,566 m 1999: 2,474 m >10 m/yr
>1 m/yr 1933: 2,374 m Similar patterns in the Sierra Nevada (Moritz 2007) [email protected] What predicts extinction? Habitat size/structure Human impacts Species interactions Thermal stress Beever et al. in press: Habitat area
Accessibility Livestock grazing Acute heat-stress Chronic heat-stress Acute cold-stress Climatic refugium [email protected] Defining local extinction Persisting N = 11 3 km N = 10
Extinct 200 m N=4 Transitional but persisting [email protected] Candidate predictors of extinction: Habitat area amount within 0.8 km, or entire mtn range 3 km Refuge elevation of highest habitat within 3 km
[email protected] Candidate predictors of extinction (continued): Accessibility distance to nearest non-4WD road Grazing long-term use of the site by livestock Acute heat stress number of days above 28C/82F Chronic heat stress average summer temperature Acute cold stress number of days below -10C/14F [email protected] Hourly haypile temperatures 40 Niwot Ridge, CO Gallatin Range, MT
30 Temperature (C) 20 10 Joyce Gellhorn temp 0 (C) -10 -20 -30 A-04 S-04 O-04 N-04 D-04
J-05 F-05 M-05 A-05 M-05 J-05 date Date (Month-Year) J-05 A-05 Hindcasting metrics of stress Study site T (C) 3 data sets: = long-term, = climate change, = recent
1945 1955 1965 3 stress metrics Acute heat-stress Chronic heat-stress Acute cold-stress 1975 1985 Data used
# days > 28 C Summer mean T # days < -10* C 1995 2005 Hindcasts >28 , >28 , >28 S , S , S <-10 , <-10 , <-10 What predicts extinction? Given the many factors that may be responsible for pika extinctions,
perhaps the only reason our list of predictors looks like this is because we havent yet had the opportunity to consider other (perhaps better) predictors, and data from other regions. Cold days (last 60 yrs) Refuge (upslope habitat) Habitat area (w/in 0.8 km)
Hot summer (recent mean) Habitat area (w/in range) Grazing [email protected] Erb, Ray & Guralnick study, in prep. Of 69 historically occupied sites in the southern Rockies, only 4 are no longer occupied The 4 local extinctions are explained by moisture issues: pikas are missing only from the driest sites
How might climate cause extinction? [email protected] Outline Motivation for an individual-based study of climatic stressors Preliminary results from a long-term study in Montana Preliminary results from a
comparative study of MT & CO pikas [email protected] Gallatin Range Demographic Study Montana Ray 1989-2009 [email protected] Gallatin Range Demographic Study Montana Ray 1989-2009 0.4
2005-2009 pika fate vs. microsite temperature 0.35 Pika survived (n = 30) 0.3 Pika died (n = 37) 0.25 0.2 0.15 0.1 Proportion of temperatures 0.05
0 -14 -10 -6 -2 2 6 10 14 Temperature (C) [email protected] 18 22
26 30 Gallatin Range Demographic Study Montana Ray 1989-2009 2008-2009 pika fate vs. microsite temperatures 0.5 Pika survived (n = 5) Pika died (n = 4) 0.4
0.3 0.2 0.1 Proportion of temperatures 0 -14 -10 -6 -2 2
6 10 14 Temperature (C) [email protected] 18 22 26
Gallatin Range Demographic Study Montana Ray 1989-2009 1.0 0.9 0.8 n adults0.7 in population 0.6 0.5 0.4 1990 1995
[email protected] 2000 Year 2005 2010 2 Gallatin Range Demographic Study Montana Ray 1989-2009
1 0 che size, -1 Aug 31 -2 -3 -4 2000 Adults Juveniles 2002 2004 2006
Year [email protected] 2008 Outline Motivation for an individual-based study of climatic stressors Preliminary results from a long-term study in Montana Preliminary results from a
comparative study of MT & CO pikas [email protected] Stress and survival study Gallatin Range, MT & Niwot Ridge, CO Ray et al., 2008-2009 Bob Rapp Stress and survival study Gallatin Range, MT & Niwot Ridge, CO Ray et al., 2008-2009 0.8
Main site, MT LTER site, CO (c) 0.6 urvival 0.4 rate 0.2 0.0 MT CO
Site Southern Northern CO slope aspect Stress and survival study Gallatin Range, MT & Niwot Ridge, CO Ray et al., 2008-2009 14 12 (d) 10 ucose8 (mg/dl) X 100
6 4 2 0 MT CO Site Stress and survival study Gallatin Range, MT & Niwot Ridge, CO Ray et al., 2008-2009 0.4 0.3
MT CO (a) temperatures 0.2 recorded 0.1 0.0 -20 -10 0
10 Temperature (C) 20 Stress and survival study Gallatin Range, MT & Niwot Ridge, CO Ray et al., 2008-2009 0.4 0.3 S aspect N aspect (b)
of temperatures 0.2 in CO 0.1 0.0 -20 -10 0 10 Temperature (C) 20 How might climate cause
extinction? ? ? ? ? ? ? [email protected] How might climate cause extinction?
Summer heat-stress Heat avoidance behavior Reduced foraging activity Smaller or inferior haypiles Winter cold-stress [email protected] How might climate cause extinction? Summer heat-stress Heat avoidance behavior Reduced foraging activity Smaller or inferior haypiles Winter cold-stress
[email protected] Haypile Pika [email protected] How might climate cause extinction? Community interactions [email protected] [email protected]
Automated camera at a marmot den Morning Late morning Noon Afternoon How might climate cause extinction? Predation [email protected]
[email protected] How might climate cause extinction? Disease [email protected] What does the future hold? Manuscript in review, by Scott Loarie et al.* models local extinction probability according to climate for 97 resurveyed pika sites Mean annual temperature
IV. Rocky Mtns III. Great Basin II. Cascade I. Sierra Decade (20th century) *S. Loarie, C. Field, C. Ray, E. Beever, P. Duffy, K. Hayhoe, J. Wilkening and J. Clark [email protected] What does the future hold? Mean annual temperature Manuscript in review, by Scott Loarie et al.* models local extinction probability according to climate
for 97 resurveyed pika sites IV. Rocky Mtns Mean annual temperature III. Great Moderate emission Basin scenarios Mid-high emission scenarios Projected
II. Cascade I. Sierra Observed Lower emission scenarios Decade (20th century) *S. Loarie, C. Field, C. Ray, E. Beever, P. Duffy, K. Hayhoe, J. Wilkening and J. Clark [email protected] Probability of local extinction Over 50% extinct by 2100?
Predictions were conservative for the Great Basin *S. Loarie, C. Field, C. Ray, E. Beever, P. Duffy, K. Hayhoe, J. Wilkening and J. Clark [email protected] The End [email protected]
