Sara J. Oyler-McCance

Evaluation of the eastern (Centrocercus urophasianus urophasianus) and western (Centrocercus urophasianus phaios) subspecies of Sage-grouse using mitochondrial control-region sequence data

The status of Sage-grouse (Centrocercusurophasianus) is of increasing concern, aspopulations throughout its range havecontracted as a result of habitat loss anddegradation. Historically, Sage-grouse wereclassified into two subspecies: eastern(C. u. urophasianus) and westernSage-grouse (C. u. phaios) based onslight differences in coloration noted amongeight individuals sampled from Washington,Oregon, and California. We sequenced a rapidlyevolving portion of the mitochondrial controlregion in 332 birds from 16 populations. Although our sampling area covers the proposedboundary between the eastern and westernsubspecies, no genetic evidence to support thedelineation of these subspecies was found. However, a population straddling southwesternNevada and eastern California was found tocontain an unusually high proportion of uniquehaplotypes, consistent with its geneticisolation from other Sage-grouse populations. Of additional interest was the lack ofdiversity in the two populations sampled fromWashington, one of which contained only asingle haplotype. We suggest that multiplelines of evidence are valuable for theformulation of conservation strategies andhence the southwestern Nevada/easternCalifornia population merits furthermorphological, behavioral, and molecular investigation.

A rangewide population genetic study of trumpeter swans

For management purposes, the range of naturally occurring trumpeter swans (Cygnus buccinator) has been divided into two populations, the Pacific Coast Population (PP) and the Rocky Mountain Population (RMP). Little is known about the distribution of genetic variation across the species’ range despite increasing pressure to make difficult management decisions regarding the two populations and flocks within them. To address this issue, we used rapidly evolving genetic markers (mitochondrial DNA sequence and 17 nuclear microsatellite loci) to elucidate the underlying genetic structure of the species. Data from both markers revealed a significant difference between the PP and RMP with the Yukon Territory as a likely area of overlap. Additionally, we found that the two populations have somewhat similar levels of genetic diversity (PP is slightly higher) suggesting that the PP underwent a population bottleneck similar to a well-documented one in the RMP. Both genetic structure and diversity results reveal that the Tri-State flock, a suspected unique, non-migratory flock, is not genetically different from the Canadian flock of the RMP and need not be treated as a unique population from a genetic standpoint. Finally, trumpeter swans appear to have much lower mitochondrial DNA variability than other waterfowl studied thus far which may suggest a previous, species-wide bottleneck.

Characterization of small microsatellite loci for use in non invasive sampling studies of Gunnison Sage-grouse (Centrocercus minimus)

Primers for 10 microsatellite loci were developed specifically to amplify low quantity and quality DNA for Gunnison Sage-grouse (Centrocercus minimus), a species that has been petitioned for listing under the US Endangered Species Act. In a screen of 20 individuals from the largest population in the Gunnison Basin, Colorado, the 10 loci were found to have levels of variability ranging from two to seven alleles. No loci were found to be linked, although one locus revealed significant departures from Hardy–Weinberg equilibrium. These microsatellite loci will be applicable for population genetic analyses and for use in mark recapture studies that utilize DNA collected non invasively from feathers and fecal pellets, which will ultimately aid in management efforts.

OCCURRENCE OF GREATER SAGE-GROUSE × SHARP-TAILED GROUSE HYBRIDS IN ALBERTA

Abstract Two distinct grouse were regularly observed at two Greater Sage-Grouse (Centrocercus urophasianus) leks in both 1999 and 2000 in southeastern Alberta. Physically and behaviorally, the birds exhibited characteristics of both Greater Sage-Grouse and Sharp-tailed Grouse (Tympanuchus phasianellus), suggesting they were hybrids. DNA analyses of blood and feather samples indicated that both birds were males with Greater Sage-Grouse mothers and thus, fathers that were likely Sharp-tailed Grouse. Ocurrencia de Híbridos entre Centrocercus urophasianus y Tympanuchus phasianellus en Alberta Resumen. Dos aves distintivas fueron observadas con regularidad en dos asambleas de cortejo de Centrocercus urophasianus en el sureste de Alberta tanto en 1999 como en 2000. Las aves presentaban características físicas y de comportamiento tanto de C. urophasianus como de Tympanuchus phasianellus, lo que sugiere que se trataba de individuos híbridos. Análisis de ADN extraído de muestras de sangre y plumas indicaron que ambos individuos eran machos hijos de hembras de C. urophasianus. Por tanto, sus padres probablemente eran T. phasianellus.

A population genetic analysis of the midget faded rattlesnake in Wyoming

Little is known about the population biology of midget faded rattlesnakes, a sensitive subspecies of the Western Rattlesnake, despite conservation efforts to protect them. We conducted a molecular genetic study of midget faded rattlesnakes in southwestern Wyoming to investigate population genetic structure in this area, particularly with reference to Flaming Gorge Reservoir and its associated human activities, and to document levels of genetic diversity. We genotyped 229 snakes from 11 sampling sites using 9 microsatellite loci. We found significant levels of genetic structure among sites that were better explained by geographic region and isolation by distance than by position relative to waterways. Sites on either side of the reservoir at its widest point were not significantly different. Six of the sites showed signatures of a population bottleneck using an alpha value of 0.05. Three of these bottlenecked sites (the three most northern) were the most genetically distinct and occur in areas of greatest impact from human activity.

Characterization of ten microsatellite loci in midget faded rattlesnake (Crotalus oreganus concolor)

Primers for 10 microsatellite loci were developed for midget faded rattlesnake (Crotalus oreganus concolor), a small bodied subspecies of the Western Rattlesnake, which is found in the Colorado Plateau of eastern Utah, western Colorado and southwestern Wyoming. In a screen of 23 individuals from the most northern portion of the subspecies range in southwestern Wyoming, the 10 loci were found to have levels of variability ranging from 4 to 11 alleles. No loci were found to be linked, although one locus revealed significant departures from Hardy–Weinberg equilibrium. These microsatellite loci will be applicable for population genetic analyses, which will ultimately aid in management efforts for this rare subspecies of rattlesnake.