Block & Bridle Annual 1956-1957

Charles Adams (Faculty Advisor), Delbert Kuhlman, John Klingenberg, Ardyce Haring, Harvey Jorgensen, Roy Volzke, Billie Reed, Paul Yeutter Prof. Loeffel, Carolyn Hall, Byron Kort, Larry Paul, Elwin Mosier, Charles Corkle, Kay Robohm, Daniel Stilwell Duane Stokebrand, Gary Briggs, Walt Patterson, Wendell Mousel, Keith Smith, Darrel Zessin, Richard Bonne, Donald Kasbohm, Bruce Skinner Bob Discoe, Doyle Hulme, Jim Smith, Carl Lorenzen, Jay Cook, Gary Berke, Bob Volk, Roger Hild Donald Kuhl, Russell Person, Ray Cada, Ray DeBower, Bob Dannert, Phil Starck, Kay Knudsen, Jerry Brownfield, Allan McClure, Wally Bierman Morris Ochsner, Warren Mitchell, Ed McReynolds, Gerald Dart, Arza Snyder, Mervy Schliefert, Arley Waldo, Tom Hoffman, John Wink, Virgil Gellermann, Duane Neuman

Comparison of Two Roadside Survey Procedures for Dwarf Mistletoes on the Sawtooth National Forest, Idaho

Two roadside surveys were conducted for dwarf mistletoes parasitizing lodgepole pine and Douglas-fir on the Sawtooth National Forest, Idaho. One survey used variable-radius plots located less than 150 m from roads. The 2nd survey used variable-radius plots established at 200-m intervals along 1600-m transects run perpendicular to the same roads. Estimates of the incidence (percentage of trees infected and percentage of plots infested) and severity (average dwarf mistletoe rating) for both lodgepole pine and Douglas-fir dwarf mistletoes were not significantly different for the 2 survey methods. These findings are further evidence that roadside-plot surveys and transect-plot surveys conducted away from roads provide similar estimates of the incidence of dwarf mistletoes for large forested areas.

Contrasting patterns of genetic diversity at three different genetic markers in a marine mammal metapopulation

Many studies use genetic markers to explore population structure and variability within species. However, only a minority use more than one type of marker and, despite increasing evidence of a link between heterozygosity and individual fitness, few ask whether diversity correlates with population trajectory. To address these issues, we analyzed data from the Steller’s sea lion, Eumetiopias jubatus, where three stocks are distributed over a vast geographical range and where both genetic samples and detailed demographic data have been collected from many diverse breeding colonies. To previously published mitochondrial DNA(mtDNA) and microsatellite data sets,we have added new data for amplified fragment length polymorphism (AFLP) markers, comprising 238 loci scored in 285 sea lions sampled from 23 natal rookeries. Genotypic diversity was low relative to most vertebrates, with only 37 loci (15.5%) being polymorphic. Moreover, contrasting geographical patterns of genetic diversity were found at the three markers, with Nei’s gene diversity tending to be higher for AFLPs and microsatellites in rookeries of the western and Asian stocks, while the highest mtDNA values were found in the eastern stock. Overall, and despite strongly contrasting demographic histories, after applying phylogenetic correction we found little correlation between genetic diversity and either colony size or demography. In contrast, we were able to show a highly significant positive relationship between AFLP diversity and current population size across a range of pinniped species, even though equivalent analyses did not reveal significant trends for either microsatellites or mtDNA.