POSTERS
Scoresby S, Spencer E, Epps CW, Crowhurst, R, Graves TA. 2024. Bighorn Sheep Population Structure in Dinosaur National Monument. Poster for the Joint Arizona- New Mexico meeting of the Wildlife Society. February 2, 2024, Flagstaff, AZ
Abstract:
Bighorn sheep (Ovis canadensis) in Dinosaur National Monument were extirpated in the late 1940s, largely due to introduced disease and overhunting, but were translocated back into the Monument 5 times between 1952 and 2007. The 83,000 ha Monument is divided by the Yampa and Green Rivers, but our initial hypothesis of these rivers as landscape barriers was not supported. Because reintroduced herds are especially susceptible to inbreeding depression and population bottlenecks, we evaluated genetic structure and diversity of this metapopulation. Genetic structure can show spatial patterns and lend insight on levels of movement and interaction between social groups. Those factors are especially important because a domestic sheep (Ovis aries) grazing allotment occurs in Dinosaur National Monument, and domestic sheep can be a source of Mycoplasma ovipnuemoniae, a respiratory disease that can cause population declines.
We collected fecal samples (n=798) along the Yampa and Green rivers within the boundaries of Dinosaur National Monument during the summers of 2018-2021. We extended genotypes for 118 individuals at 16 microsatellite loci to evaluate genetic structure. Within this geographically small area we found evidence for 4 distinct populations. These populations are well within dispersal distances observed in other bighorn metapopulations. Mixing among populations is evident, as are first- and second-generation offspring. These populations are unusually genetically distinct but also show clear evidence of recent migrants. The limited movement suggested in our analyses may afford some protection against disease spread between these populations.
Scoresby S, Piasecki J, Moriarty K. 2022. Red Tree Vole Nest Density and Stand Age. Poster for the International Conference of The Wildlife Society. November 7, 2022, Spokane, WA
Abstract:
For species occupying managed forest in a mosaic of differently aged stands, understanding nesting preference and use in relation to stand age is challenging and may hold great value in better understanding species of conservation interest. Red tree voles (Arborimus longicaudus) are elusive canopy-dwelling rodents and are considered an old-forest obligate species. However, red tree voles are also found in young managed forests. Over four field seasons (2019-2022) we climbed >700 trees with nest structures identified from the ground across 50 stands from 20 to >300 years old. We documented recent use by red tree voles (e.g., resin ducts, debarked twigs). We surveyed for red tree vole nests in forests from 0-5000 m from old (80+ year old) forests. Tree vole presence and nest density were expected to be negatively correlated with increased distance from older forest, with recently used nests found at a maximum distance of 1300 m from old forest. We will use our data to further investigate whether and how tree vole presence is associated with distance from old forest. Our data on the relationship between red tree vole presence in young forest and stand distance from old forest provides new ecological information and can aid in management and conservation of canopy obligate species.
Scoresby S, Piasecki J, Moriarty K. 2022. Multi-Species Presence in Red Tree Vole Nests. Poster for the Western Section Conference of The Wildlife Society. February 9, 2022, Reno, NV
Abstract:
For species occupying the forest canopy, finding adequate shelter can be a limiting resource. Understanding nest preference and use is challenging and may hold great value in better understanding species of conservation interest. Red tree voles (Arborimus longicaudus) are elusive canopy-dwelling rodents and little has been documented regarding interspecific use of their nests. While monitoring has occurred on artificial nest platforms used by tree voles, quantifiable use of natural tree vole nests by other mammals in managed forests is unknown. Over three field seasons (2019, 2020, 2021) we climbed 713 trees with nest structures identified from the ground across 45 stands from 20 to >300 years old. We documented recent use by red tree voles (e.g., resin ducts, debarked twigs) and installed cameras to record species occurrence. We observed multiple species using red tree vole nests, often simultaneously within a day. Our data suggests nest construction and usage frequently cannot be attributed to a single species, and that not all interspecific nest usage is antagonistic. We will use our data to investigate whether concurrent nest use, relative nest availability, and a relative index of mammal diversity were associated with stand age. Our data on these interspecific relationships provides new ecological information and can aid in management and conservation of canopy obligate species.