27732 – Small Mammal Inventories in Klamath Network

Investigator’s Annual Reports (IAR’s) for Crater Lake National Park

Small Mammal Inventories in Klamath Network National Parks, Monuments, and Recreation Areas – Crater Lake National Park


Report Number: 27732

Permit Number: CRLA-2002-SCI-0009

Current Status: Checked in

Date Received: Mar 17, 2004

Reporting Year: 2002

Principal Investigator: Mr Scott Mahady, Klamath Network-National Park Service, Ashland, OR

Additional investigator(s): Daniel Sarr, Daryl Weldon

Park-assigned Study Id. # CRLA-02032

Permit Expiration Date: Oct 14, 2002

Permit Start Date: Jul 08, 2002

Study Starting Date: Jul 08, 2002

Study Ending Date: Oct 14, 2002

Study Status: Completed

Activity Type: Inventory

Subject/Discipline: Mammals

Objectives: The primary objective of this study is to cunduct a small mammal inventory that will accurately document the presence of at least 90 percent all small mammal species ossurring in the Crater Lake National Park. The second objective of this inventory will be to document distribution of the species encountered within the habitats sampled in each park and across the Klamath Network as a whole. The third objective will be to provide baseline data for the Klamath Network that could be used to create an effective small mammal monitoring program.

This network effort will necessarily be customized in Lassen Volcanic National Park to best complement existing inventory information and ongoing monitoring activities.

Findings and Status:  Three 240m transects were trapped at CRLA. One linear transect was set on a rocky hillside (Hillman Peak), one linear transect was placed in a wet meadow/riparian area, and the third transect was linear and placed in a mature lodgepole pine forest.

Eight species were observed from 145 captures during a 600 trap night effort. Trap success averaged 24.2%. The Pacific Jumping Mouse (Zapus trinotatus) accounted for 37% (54/147) of all captures. Unique captures included an Ermine (Mustela erminea) along with a Mazama Pocket Gopher (Thomomys mazama). The other six species observed were all known to be present at the park.

Recommendations for surveying in the 2003 season include focusing effort on delineating the Townsend complex of chipmunks in the park. Road kills and other specimens should be collected to attempt to accurately document the four different Tamias species that are likely present within the park. Modification of the trapping schedule should be attempted so that sherman live traps are left open during the morning after the traps are checked at dawn, and rechecked and closed in two to three hours. By running the Sherman live traps for a few hours during the morning it would be possible to document the presence of the different chipmunk species. Inventory surveys should also attempt to document the presence of the pinon mouse (Peromyscus treui), the White-footed Vole, the Heather Vole (Phenacomys intermedius), and the Townsend’s Vole (Microtus townsendii). The Pinon Mouse inhabits dry areas with Pinon Pine and/or juniper trees. The White-footed Vole inhabits dense woodlands along riparian corridors. The Heather Vole appears to be rather general in its habitat affinities and surveys for it could be conducted in montane/subalpine meadows, along riparian corridors near woodlands, and in stands of Douglas-fir or Engelman Spruce. The Townsend’s Vole can be difficult to live trap, but is easily taken by snap traps, and is found in wet grassland habitats such as lowland meadows, boggy areas and marshes.

Data management recommendations include checking on the voucher of Clethrionomys gapperi and Clethrionomys californicus. It is unlikely that both species are present at the park. The voucher specimen lists C.g.mazama. Yet only C.g.idahoensis is supposed to occurs in Oregon. Further information that this voucher may be incorrectly identified is C. californicus mazama is one of the three recognized sub-species of C. californicus to occur in Oregon. Also, Clethrionomys occidentalis is no longer used and should be changed to Clethrionomys californicus. The genus Eutamias should be changed to Tamias. Voucher specimens collected from Crater Lake National Park for four species: Phenacomys (Arborimus) intermedius, Sorex sonomae, Tamias senex, and Sorex pacificus, are all listed in the ?The Land Mammals of Oregon?. Sorex pacificus is not even on the species list for Crater Lake. These specimens should be located and their information entered into ANCS, and the species list updated as needed.

For this study, were one or more specimens collected and removed from the park but not destroyed during analyses? Yes

Funding provided this reporting year by NPS: 4680

Funding provided this reporting year by other sources: 0

Full name of college or university:  n/a

Annual funding provided by NPS to university or college this reporting year: 0


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