Pika Inventory

Background and UCBN involvement

Recently, localized extirpations of the American pika (Ochotona princeps) have been documented in isolated mountain ranges of the Great Basin (Beever et al. 2003). Some scientists believe that these extirpations may be due to increased warming resulting from accelerated climate change, and given the current predictions of climate change over the next century, the risk of extinction is now considerable (Beever et al. 2003, Wagner et al. 2003, Grayson 2005, Parmesan 2006).

The lava flow environments found at Craters of the Moon National Monument and Preserve (CRMO) provide a unique and potentially critical habitat type for pika (Beever 2002). The cool microclimates in the deep cracks and crevices of the lava flows allow pika to survive despite extreme summer surface temperatures. These flows are extensive, which presumably permits a much larger and more genetically diverse population to persist than those in highly fragmented montane environments. Consequently, Craters of the Moon could become a regionally significant refugia for the species if warming over the next century occurs as predicted (sensu Wagner et al. 2003), and the need for establishing a baseline against which future population change can be detected is clear.

Though the Upper Columbia Basin Network has not included pika in its top tier of vital signs for immediate protocol development, it recognizes the importance of establishing a long-term monitoring program for this species. Pika are well suited for presence-absence surveys and given the vast area of potential habitat at Craters of the Moon, this approach is highly efficient. The approach by Mackenzie et al. (2002, 2006) for estimating occupancy in a species detected imperfectly provides as ideal framework for evaluating both status and trend of the pika population in Craters of the Moon, and for testing hypotheses about environmental drivers of pika populations. While occupancy is not a direct index for abundance, it is an appropriate status and trend metric for pika due to their highly territorial nature and a strong positive correlation is assumed to exist between site occupancy and abundance. The UCBN hopes to survey a random sample of points within the monument every year for pika occupancy.

2008 Objectives

2008 pika survey objectives are as follows:

• Establish the current southern/lower elevational limit of pika in CRMO.
• Identify and define two new study areas in southern/lower elevation portions of the Preserve with sufficient pika sign to enable comparisons with the Monument study area surveyed in 2007.
• Provide robust model-based estimates of September site occupancy probabilities for the two new study areas based on vegetation cover, lava flow type, lava flow structural complexity, and distance to lava flow edge.
• Develop two independent occupancy datasets from analogous study areas in lower elevations of the Preserve to test and validate the occupancy model developed using the September 2007 Monument study area dataset.
• Provide an estimate of pika detectability as a function of time of day, survey search time, and detection method (e.g. animal sighting vs. sign). In 2008, attention will be given to June/July detectability using direct sign, compared with the 2007 September results.
• Collect sufficient data following common methods to support a formal comparison (e.g. model validation) of results from this survey and the 2005-2006 survey at Lava Beds National Monument.
• Evaluate the candidate survey and analytical methods with data collected in 2007 and make recommendations for designing an efficient long-term monitoring program for pika in CRMO.
• Collect fecal samples for preliminary analysis of DNA as pilot work for determining effective population size, genetic diversity of Craters population(s), dispersal and metapopulation dynamics, and population structuring.

Results/Future Plans

Results from 2007 suggest that pika are readily detected when present if indirect sign (e.g. fresh scat and haypiles) is relied upon. Pika were not found in any of the southernmost portions of the CRMO preserve area, although this search was not exhaustive and additional effort will be made in this area in 2008. The significance of this is that the southern portions of the Preserve are also the lowest elevation (approx 4000’). In the 2000 ha intensively surveyed portion of the original CRMO Monument, the preliminary estimate of proportion of area occupied by pika was 0.2 (20%). This study area is in the northernmost and highest elevation portion of the park (approx 6000’). Pika were much more likely to be found on highly complex Pahoehoe lava with moderate amounts of forb cover. Rough Aa lava sites tended to be unvegetated and no pika were found in these areas. Additional surveys in 2008 will provide information to test these results across the Preserve. The UCBN and CRMO science and resource staff are teaming up with other members of the NPS Pacific West Region and outside researchers to coordinate pika survey and monitoring efforts across the Region. Updates, protocols, and reports will be linked from our website as they become available.

Contact Information

Tom Rodhouse
Upper Columbia Basin Network Ecologist
National Park Service
2600 NW College Way - Ponderosa Bldg.
Bend, OR 97701
Email

Document Links

• Pika Inventory Protocol (2008)
• Resource Brief (link to Reports & Pubs page)
• Pika Survey Report (link to Inventory Reports page)

Literature Cited

Beever, E. A. 2002. Persistence of pikas in two lower elevation National Monuments in the western United States. Park Science 21:23-29.

Beever, E. A., P. E. Brussard, and J. Berger. 2003. Patterns of apparent extirpation among isolated populations of pikas (Ochotona princeps) in the Great Basin. Journal of Mammalogy 84:37-54.

Grayson, D. K. 2005. A brief history of Great Basin pikas. Journal of Biogeography 32:2103-2111.

MacKenzie, D. I., J. D. Nichols, G. B. Lachman, S. Droege, J. A. Royle, and C. A. Langtimm. 2002. Estimating site occupancy rates when detection probabilities are less than one. Ecology 83: 2248-2255.

MacKenzie, D. I., J. D. Nichols, J. A. Royle, K. H. Pollock, L. L. Bailey, and J. E. Hines. 2006. Occupancy estimation and modeling: inferring patterns and dynamics of species occurrence. Elsevier, London, England.

Parmesan, C. 2006. Ecological and evolutionary responses to recent climate change. Annual Review of Ecology Evolution and Systematics 37:637-669.

Wagner, F. H., R. Angell, M. Hahn, T. Lawlor, R. Tausch, and D. Toweill. 2003. Natural ecosystems III. The Great Basin. Pages 207-240 in F. H. Wagner, editor. Rocky Mountain/Great Basin regional climate-change assessment. Report for the US global change research program. Utah State University, Logan, UT.