Geology topics

Jason D. Carlisle

Publications and source records attributed to Jason D. Carlisle.

6 recordsLinked to original sources

USGS2022

Intrabrood variation in nestling mass among three sagebrush-associated songbirds

The young of some altricial bird species hatch asynchronously, which can lead to considerable size differences among siblings. Nestling traits such as body mass, moreover, can carry over and influence post-fledging survival. Despite the potential importance of nestling mass for reproductive outcomes, however, variation in nestling mass and relationships with brood size has been described and quantified rarely. We weighed 453 nestlings from 148 nests of 3 sympatric, sagebrush-associated songbird species in Wyoming, USA, to describe the range of intrabrood mass differences. Intrabrood differences in nestling mass were greatest for the largest species, the Sage Thrasher ( Oreoscoptes montanus ), for which the smallest nestling in a brood was on average 26.2% smaller than the largest. The smaller Vesper Sparrow ( Pooecetes gramineus ) and Brewer's Sparrow ( Spizella breweri ) exhibited similar intrabrood mass ratios, with the smallest nestling being 17.4% and 18.4% smaller on average than the largest for the 2 species, respectively. For each additional nestling within a brood, the smallest nestling was an additional 6.6–13.6% smaller than the largest nestling, depending on species. Understanding the extent of intrabrood variation in nestling traits has important implications for the productivity of species facing unpredictable environments.

The Wilson Journal of Ornithology↗

USGS2020

The abundance of Greater Sage-Grouse as a proxy for the abundance of sagebrush-associated songbirds in Wyoming, USA

Surrogate-species concepts are prevalent in animal conservation. Such strategies advocate for conservation by proxy, wherein one species is used to represent other taxa to obtain a conservation objective. The efficacy of such approaches has been rarely assessed empirically, but is predicated on concordance between the surrogate and sympatric taxa in distribution, abundance, and ecological requirements. Our objective was to identify whether the abundance of a high-profile umbrella species (Greater Sage-Grouse, Centrocercus urophasianus , hereafter sage-grouse) was associated with the abundance of six other members of the avian community for which it is presumed to be a surrogate, including three sagebrush-obligate and three sagebrush-associated songbird species. We predicted that sage-grouse abundance would align most closely with the breeding abundance of other sagebrush-obligate birds. We used two different indices of sage-grouse abundance for comparisons: field-collected counts of fecal pellets (primarily indexing abundance in the nonbreeding season) and a spatially explicit index of breeding population size. Neither index of sage-grouse abundance was consistently predictive of co-occurring songbird abundance, with one species more abundant (Horned Lark [ Eremophila alpestris ]) and one species less abundant (Vesper Sparrow [ Pooecetes gramineus ]) where sage-grouse pellet counts were higher, and no relationship evident between songbird abundance and the spatially explicit sage-grouse population index. Ours is one of few assessments of the efficacy of sage-grouse as a surrogate species to consider abundance, and not habitat overlap alone. We suggest that the utility of sage-grouse as a surrogate species likely varies across spatial scales. Within the scale examined here (10–15 ha sites), however, indices of sage-grouse abundance were unreliable proxies for the abundance of six declining songbird species.

Wyoming↗

USGS2018

Identifying holes in the greater sage-grouse conservation umbrella

The umbrella species concept, wherein multiple species are indirectly protected under the umbrella of a reserve created for one, is intended to enhance conservation efficiency. Although appealing in theory and common in practice, empirical tests of the concept have been scarce. We used a real-world, semi-protected reserve established to protect a high-profile umbrella species (greater sage-grouse [ Centrocercus urophasianus ]) to investigate 2 potential mechanisms underlying the concept's successful application: reserve size and species similarity. We estimated how much habitat protection the established reserve provided to 52 species of conservation concern associated with vegetation communities where greater sage-grouse occur. To illustrate the importance of reserve size, we compared the effectiveness of the established reserve to alternative greater sage-grouse reserves of various sizes and to simulated reserves of equal size but sited with no regard for greater sage-grouse. We further assessed whether key species’ traits were associated with different levels of protection under the umbrella reserve. The established umbrella reserve protected 82% of the state's greater sage-grouse population and 0–63% of the habitat of the background species examined. The reserve outperformed equally sized, simulated reserves for only 12 of 52 background species. As expected, larger alternative reserves served as better umbrellas, but regardless of reserve size, not all species received equal protection. The established reserve was most effective at protecting the habitat of species that were most similar to the umbrella species (i.e., avian species, those highly associated with sagebrush plant communities, and those with widespread habitat). In contrast, the habitat of species with restricted distributions, particularly when combined with vegetation associations not closely matching the umbrella species, was not protected as well by the umbrella reserve. Such species require additional, targeted attention to achieve conservation objectives. Successful application of the umbrella species concept requires careful consideration of the characteristics of the umbrella species, the reserve delineated on its behalf, and the similarity of the umbrella species to its purported background species.

Wyoming↗

USGS2018

Non-target effects on songbirds from habitat manipulation for Greater Sage-Grouse: Implications for the umbrella species concept

The “umbrella species” concept is a conservation strategy in which creating and managing reserve areas to meet the needs of one species is thought to benefit other species indirectly. Broad-scale habitat protections on behalf of an umbrella species are assumed to benefit co-occurring taxa, but targeted management actions to improve local habitat suitability for the umbrella species may produce unintended effects on other species. Our objective was to quantify the effects of a common habitat treatment (mowing of big sagebrush [ Artemisia tridentata ]) intended to benefit a high-profile umbrella species (Greater Sage-Grouse [ Centrocercus urophasianus ]) on 3 sympatric songbird species of concern. We used a before–after control-impact experimental design spanning 3 yr in Wyoming, USA, to quantify the effect of mowing on the abundance, nest-site selection, nestling condition, and nest survival of 2 sagebrush-obligate songbirds (Brewer's Sparrow [ Spizella breweri ] and Sage Thrasher [ Oreoscoptes montanus ]) and one open-habitat generalist songbird (Vesper Sparrow [ Pooecetes gramineus ]). Mowing was associated with lower abundance of Brewer's Sparrows and Sage Thrashers but higher abundance of Vesper Sparrows. We found no Brewer's Sparrows or Sage Thrashers nesting in the mowed footprint posttreatment, which suggests complete loss of nesting habitat for these species. Mowing was associated with higher nestling condition and nest survival for Vesper Sparrows but not for the sagebrush-obligate species. Management prescriptions that remove woody biomass within a mosaic of intact habitat may be tolerated by sagebrush-obligate songbirds but are likely more beneficial for open-habitat generalist species. By definition, umbrella species conservation entails habitat protections at broad spatial scales. We caution that habitat manipulations to benefit Greater Sage-Grouse could negatively affect nontarget species of conservation concern if implemented across large spatial extents.

Wyoming↗

USGS2018

Nest mortality of sagebrush songbirds due to a severe hailstorm

Demographic assessments of nesting birds typically focus on failures due to nest predation or brood parasitism. Extreme weather events such as hailstorms, however, can also destroy eggs and injure or kill juvenile and adult birds at the nest. We documented the effects of a severe hailstorm on 3 species of sagebrush-associated songbirds: Sage Thrasher ( Oreoscoptes montanus ), Brewer's Sparrow ( Spizella breweri ), and Vesper Sparrow ( Pooecetes gramineus ), nesting at eight 24 ha study plots in central Wyoming, USA. Across all plots, 17% of 128 nests failed due to the hailstorm; however, all failed nests were located at a subset of study plots ( n = 3) where the hailstorm was most intense, and 45% of all nests failures on those plots were due to hail. Mortality rates varied by species, nest architecture, and nest placement. Nests with more robust architecture and those sited more deeply under the shrub canopy were more likely to survive the hailstorm, suggesting that natural history traits may modulate mortality risk due to hailstorms. While sporadic in nature, hailstorms may represent a significant source of nest failure to songbirds in certain locations, especially with increasing storm frequency and severity forecasted in some regions with ongoing climate change.

Wilson Journal of Ornithology↗

USGS2017

An intertebrate ecosystem engineer likely covered under the umbrella of sage-grouse conservation

Conservation practitioners often rely on areas designed to protect species of greatest conservation priority to also conserve co-occurring species (i.e., the umbrella species concept). The extent to which vertebrate species may serve as suitable umbrellas for invertebrate species, however, has rarely been explored. Sage-grouse ( Centrocercus spp.) have high conservation priority throughout much of the rangelands of western North America and are considered an umbrella species through which the conservation of entire rangeland ecosystems can be accomplished. Harvester ants are ecosystem engineers and play important roles in the maintenance and function of rangeland ecosystems. We compared indices of the abundance of western harvester ants ( Pogonomyrmex occidentalis ) and Greater Sage-Grouse ( Centrocercus urophasianus ) at 72 sites in central Wyoming, USA, in 2012. The abundance of harvester ant mounds was best predicted by a regression model that included a combination of local habitat characteristics and the abundance of sage-grouse. When controlling for habitat-related factors, areas with higher abundances of sage-grouse pellets (an index of sage-grouse abundance and/or habitat use) had higher abundances of ant mounds than areas with lower abundances of sage-grouse pellets. The causal mechanism underlying this positive relationship between sage-grouse and ant mound abundance at the fine scale could be indirect (e.g., both species prefer similar environmental conditions) or direct (e.g., sage-grouse prefer areas with a high abundance of ant mounds because ants are an important prey item during certain life stages). We observed no relationship between a broad-scale index of breeding sage-grouse density and the abundance of ant mounds. We suspect that consideration of the nonbreeding habitat of sage-grouse and finer-scale measures of sagegrouse abundance are critical to the utility of sage-grouse as an umbrella species for the conservation of harvester ants and their important role in rangeland ecosystems.

Western North American Naturalist↗