Publications
Relationships among Birds, Willows, and Native Ungulates in and around Northern Yellowstone National Park
A threshold of tolerance for browsing exists among bird species in Yellowstone's riparian zones, beyond which both bird density and species richness decline significantly. This study, conducted across eight willow stands with varying levels of elk and moose browsing (ranging from 3.5% to 100% severely browsed willows), found that only two sites supported all five focal bird species (Common Yellowthroat, Lincoln's Sparrow, Warbling Vireo, Wilson's Warbler, and Yellow Warbler). The Lincoln's Sparrow was the only species present in all stands. Using data from 1989–1990, researchers measured bird densities and habitat structure variables, revealing that browsing intensity, shrub height heterogeneity, foliage density, and landscape factors (e.g., hydrology, adjacent community type) collectively shape bird assemblages. While browsing directly affects bird communities, predictive models incorporating broader ecological variables could improve accuracy.
Gray wolf habitat use in response to visitor activity along roadways in Yellowstone National Park
Gray wolves in Yellowstone National Park adjust their habitat use in response to visitor activity, particularly along roadways. Research found that wolves tend to avoid areas closer to roads during the day and peak visitation periods, especially in summer, indicating a behavioral shift likely due to human presence. While prey availability did not significantly influence this pattern, the degree of road avoidance varied among wolf packs, with some becoming more tolerant to human activity—potentially increasing their vulnerability to human-related risks if they venture outside the park. The study used seasonal and diel-specific step selection functions (SSFs) to analyze these patterns from 1979 to 2017, providing insights that could guide adaptive management strategies to conserve natural wolf behavior amid rising visitation.
How climate impacts the composition of wolf‐killed elk in northern Yellowstone National Park
Climate significantly influences the composition of wolf-killed elk in northern Yellowstone National Park, affecting prey population dynamics. The study found that wolves are more likely to kill bulls or calves under specific climatic conditions, such as low snow water equivalent (SWE) and poor vegetation productivity, rather than cows—who are crucial for population reproduction. Over 20 winters, researchers monitored 17 wolf packs, analyzing the sex, age, and nutritional condition of elk kills in early and late winter periods. They discovered that summer plant productivity, SWE, and elk abundance interact to determine whether wolves target bulls, cows, or calves, with climate acting as a key mediator in predation patterns.
Magma Intrusion and Volatile Ascent Beneath Norris Geyser Basin, Yellowstone National Park
A recent study reveals that the rapid uplift and subsidence observed near Norris Geyser Basin, Yellowstone National Park, are driven by evolving processes of deep magma intrusion followed by volatile ascent. The research, utilizing Global Positioning System (GPS) and interferometric synthetic aperture radar (InSAR) data, shows that between 1996–2001, deep magma intrusion occurred, which was later followed by the ascent and accumulation of volatiles at shallow depths—possibly as shallow as a few hundred meters. This shallow volatile accumulation has progressively shallowed from the 2014 to the 2016 deformation episodes, correlating with increased eruptions of Steamboat Geyser since March 2018. The study also highlights an elevated risk of hydrothermal explosions in this region due to the shallow nature of volatile accumulation.
Relative Abundance of Thiolated Species of As, Mo, W, and Sb in Hot Springs of Yellowstone National Park and Iceland
Research reveals that thiolated species of arsenic (As), molybdenum (Mo), tungsten (W), and antimony (Sb) are prevalent in sulfide-rich hot springs, particularly in Yellowstone National Park and Iceland. Thioarsenates were the most abundant and widespread, often dominating arsenic speciation, while thiomolybdates also dominated in many Icelandic springs. Thiotungstates and thioantimonates were less frequent but still significant contributors. The study highlights that thiolation substantially influences the speciation of these elements, with higher sulfide-to-metal(loid) ratios leading to greater thiolation, especially in Icelandic systems. These findings underscore the necessity of analyzing thiolated species when studying geothermal environments, as traditional methods often overlook their presence.
Temperature impacts community structure and function of phototrophic Chloroflexi and Cyanobacteria in two alkaline hot springs in Yellowstone National Park
Temperature plays a key role in shaping the distribution and activity of phototrophic Chloroflexi alongside Cyanobacteria in alkaline hot springs, challenging previous assumptions that only temperature constrains these microbial communities. While phototrophic Cyanobacteria richness and oxygenic photosynthesis declined with increasing temperature, Chloroflexi maintained diversity and anoxygenic photosynthetic rates even at near the upper thermal limits (~72-73°C). This suggests niche differentiation among Chloroflexi taxa, potentially influenced by factors beyond temperature such as morphology or metabolic pathways. The study used 16S rRNA gene sequencing and photoassimilation microcosms to analyze samples from 45 to 72°C in two Yellowstone hot springs, revealing distinct temperature-driven distributions for Roseiflexus, Chloroflexus (Chloroflexi), and Leptococcus (Cyanobacteria). Carbon isotopic data further indicated shifting metabolic pathways with temperature. These findings highlight the resilience and adaptability of phototrophic Chloroflexi in extreme environments.
Quantifying Bufo boreas connectivity in Yellowstone National Park with landscape genetics
A novel application of Random Forests to landscape genetic data reveals that habitat permeability, topographic morphology, and temperature–moisture regimes significantly influence the connectivity of Bufo boreas (the Yellowstone toad) in Yellowstone National Park. The study found that growing-season precipitation, fire history (specifically the 1988 Yellowstone fires), cover, temperature, impervious surfaces like roads, and topographic complexity explain 56% of the variation in connectivity. Notably, habitat permeability operates on fine scales, while topographic and climatic factors affect connectivity across multiple scales, emphasizing the need for cross-scale analysis. Hierarchical analysis further showed that within-genetic clusters (identified using Structure), dispersal cover, precipitation, and impervious surfaces explained more variation (74%) than between clusters (45%), highlighting the importance of fine-scale ecological processes in shaping population structure.
You are here:
World Heritage Explorer > World Heritage Research > World Heritage Sites > Yellowstone National Park