Importance / Issues

Amphibians are an essential element of aquatic biodiversity in montane environments of Lassen Volcanic National Park and in other parks with montane lakes and wetlands.  Amphibians are typically the top native vertebrate predators and may comprise the majority of biomass in montane lakes, streams, and wetlands.  Since amphibian declines are occurring throughout the Pacific Northwest and California, any quantitative study which helps to disentangle the factors affecting montane amphibian populations will contribute to the body of science about regional amphibian declines.  Consequently, it will help scientists and managers in other parks to better understand the possible factors influencing their amphibian populations, as well as to grasp the inevitable regional variation in such relationships.  Findings from a study of fish and amphibians at LAVO will have immediate value for both conservation and restoration within the park and region-wide.

Recent declines in the Cascades frog in Lassen Volcanic National Park have demonstrated that park populations are in immediate risk of extirpation.  It is unknown how many frogs remain in the park, the factors causing the decline, and the species’ prospect for recovery.  A rigorous, quantitative analysis of fish and frog populations is essential to preserve this element of park biodiversity.  Abundances and population trajectories for other amphibian species are even less well known.  Conservation and restoration of native amphibians in the park will require quantitative information on relationships between animal populations and the factors believed to be responsible for this decline.

Final Report

Stead, J.E., Welsh Jr. H.H., and Pope, K.L. 2005. Census of Amphibians and Fishes in Lentic Habitats of      Lassen Volcanic National Park: A Report to the National Park Service. LAVO Study Number: LAVO -      00717.

Sarr, D. and Parker, M. 2003. An Analysis of Fish and Amphibian Distributions in Lentic Environments of      Lassen Volcanic National Park.

Final Deliverables

A zipped file of all the final deliverables from this inventory (final reports, GIS data, and raw data) is accessible from the NPS Data Store at: http://science.nature.nps.gov/nrdata/metadata.cfm?ID=48339

Results Summary

Lassen Volcanic National Park

During the 2004 summer field season we conducted 442 site visits at LAVO, and surveyed all mapped sites at least once. These visits were conducted at a total of 365 unique sites and included 68 revisits.

Amphibians

Amphibian species detected during the 2004 field season included Pacific tree frogs (Hyla regilla), western toad (Bufo boreas), long-toed salamander (Ambystoma macrodactylum), Cascade frog (Rana cascadae), and rough-skinned newt (Taricha granulosa). At least one species of amphibian was detected in 61% of the sites surveyed, 49% of the sites surveyed in the Caribou Wilderness, and 89% of the sites surveyed in the Thousand Lakes Wilderness. Neither Cascades frogs nor rough-skinned newts were detected in either of the proximal wilderness areas.

The Cascades frog was detected at only three of the sites surveyed, all located within the Kings Creek watershed. Frogs were not detected at either of the small, nameless sites where they had previously been found. No Cascades frog egg masses, larvae, or evidence of breeding was encountered during the course of the survey.

The rough-skinned newt was detected at two sites in LAVO but was not detected in either of the proximal wilderness areas. The sites are located in adjacent watersheds on the western edge of the park.

The western toad was detected at 8% of sites in LAVO, 10% of sites in the Thousand Lakes Wilderness, and at one site in the Caribou Wilderness. In LAVO, toads were found at 21% of lakes, 3% of the temporary ponds, 13% of the wet meadows, and 6% of the permanent ponds surveyed.

The long-toed salamander was detected at 10% of sites in LAVO, 13% of sites in the Caribou Wilderness, and 26% of the sites in the Thousand Lakes Wilderness. Salamanders were detected in lakes, permanent ponds, and temporary ponds. In addition, salamanders were also found in wet meadows in LAVO. Of the 115 sites in the three study areas where long-toed salamanders were detected, only two contained fish.

The Pacific tree frog was the most commonly encountered amphibian species in the investigation. Tree frogs were detected at 61% of the sites in LAVO, 49% of the sites in the Caribou Wilderness, and 89% of the sites in the Thousand Lakes Wilderness. They were detected in all site types surveyed, and generally found associated with permanent water.

Reptiles

Garter snakes are known to be important predators of amphibians in environments such as LAVO (Jennings et al. 1992; Matthews et al. 2002), and are one of the target species for the visual encounter surveys. Other reptile species detected at LAVO include the northern and southern alligator lizards (Elgaria coerulea and E. multicarinata, respectively), the sagebrush lizard (Sceloperous graciosus), and the western fence lizard (S. occidentalis). One rubber boa (Charina bottae) was encountered incidentally in an upland habitat in Blue Lake Canyon, at the western boundary of the park.

Garter snakes were detected at 26% of sites at LAVO, 19% of sites in the Caribou Wilderness and at 22% of sites in the Thousand Lakes Wilderness.  Garter snakes were detected at lakes, permanent ponds, temporary ponds and wet meadows.  Two species of garter snake were detected at LAVO and in the Caribou Wilderness, the western terrestrial garter snake (Thamnophis elegans), and the common garter snake (T. sirtalis). T. sirtalis was more common than T. elegans in both areas, and only T. sirtalis was detected in the Thousand Lakes Wilderness.

Fish

Fish species detected at LAVO during the 2004 field season include brook trout (Salvelinus fontinalis), brown trout (Salmo trutta), rainbow trout (Oncorhynchus mykiss), tui chub (Gila bicolor), golden shiner (Notemigonus crysoleucas), fathead minnow (Pimephales promelas), speckled dace (Rhinichthys osculus), Lahontan redside (Richardsonius egregious) and Tahoe sucker (Catostomus tahoensis).

At LAVO, we detected fish at 23 survey sites, primarily in lakes, permanent ponds, and wet meadows.  About half of these sites contain only trout.  Eleven of the 42 sites that were documented as historically stocked still support fish.  Four of those sites have only non-trout species, so actually only eight of the historically stocked sites now have reproducing trout populations. Fish were also present at twelve sites in LAVO where we could not confirm historic stocking. Some of these sites may have been stocked, although without record.  Others were likely colonized by fish traveling from stocked lakes via connecting streams. 

The only species of fairy shrimp detected at LAVO was Streptocephalus sealii. This species is known from a number of sites in the Cascades-Sierra Nevada region (Eriksen and Belk 1999).