Population ecology of mountain goats in relation to climate, weather and snow avalanches
| dc.contributor.author | White, Kevin Scott | |
| dc.contributor.supervisor | Darimont, Chris T. | |
| dc.date.accessioned | 2025-05-22T21:03:47Z | |
| dc.date.available | 2025-05-22T21:03:47Z | |
| dc.date.issued | 2025 | |
| dc.degree.department | Department of Geography | |
| dc.degree.level | Doctor of Philosophy PhD | |
| dc.description.abstract | Weather and climate exert profound influences on wildlife populations. In mountain environments climate is changing rapidly, compared with surrounding lowland areas, highlighting the importance of understanding the population ecology of species inhabiting these sensitive and biodiverse systems. My dissertation research focused on how weather and climate, and related phenomena (i.e. snow avalanches), influence the population ecology of mountain goats – a sentinel species on mountain environments. I used long-term field data collected from individually marked animals (421 individuals over 17 years across 4 study areas in coastal Alaska) combined with remote-sensing environmental data to assess a suite of research questions. First, however, I synthesized existing information about how mountain goats are influenced by weather and climate in order to comprehensively understand the state of our knowledge and identify knowledge gaps (Chapter 2). Next, I examined how climate and life-history trade-offs shape mountain goat reproductive demography (Chapter 3). These analyses revealed age-specific patterns in reproductive performance were negatively influenced by previous parturition success, late-winter snow depth and summer temperature. Highlighting the importance of intrinsic and extrinsic factors on reproduction, these results also filled an important data gap by enabling parameterization and implementation of mountain goat population modeling simulations used to evaluate relative strength of winter vs summer effects and later analyses (described below). The remainder of my research focused on examining the extent that snow avalanches represent a climate-linked driver of mountain goat populations. In Chapter 4, principal findings revealed that avalanches comprise a major source of mortality (36% of all mortalities, on average) and can remove up to 22% of a population annually. Given the low realized population growth rate previously reported for mountain goats (i.e. 1-4%), such impacts may exert significant demographic consequences. To quantify such impacts, I next developed and implemented a population modeling approach to explicitly examine and quantify how avalanches, across a range of scenarios, influence population growth and dynamics, including recovery times (Chapter 5). Ultimately, I determined that mountain goats can sustain modest population growth (1.5%) during average avalanche conditions, but during severe years (i.e. when 23% of a population dies from avalanches) populations can experience significant declines (15%) that require extended periods (11 years, or 1.5 mountain goat generations) for recovery to baseline levels. Overall, my research contributes several dimensions of new knowledge about how weather and climate-linked factors influence mountain goats populations, and offer important insights about the functionality of mountain ecosystems in the face of changing climate conditions. | |
| dc.description.scholarlevel | Graduate | |
| dc.identifier.bibliographicCitation | White, K. S., E. Hood, G. J. Wolken, E. H. Peitzsch, Y. Bühler, K. Wikstrom Jones, and C. T. Darimont. 2024. Snow avalanches are a primary climate-linked driver of mountain ungulate populations. Communications Biology, 7: 423. | |
| dc.identifier.bibliographicCitation | K. S. White, B. Cadsand, S. D. Côté, T. Graves, S. Hamel, R. B. Harris, F. P. Hayes, E. Hood, K. Hurley, T. Jessen, B. Jex, E. Peitzsch, W. Sarmento, H. Schwantje, and J. Berger. 2025. Mountain sentinels in a changing world: review and conservation implications of weather and climate effects on mountain goats (Oreamnos americanus). Global Ecology and Conservation, e03364. | |
| dc.identifier.uri | https://hdl.handle.net/1828/22300 | |
| dc.language | English | eng |
| dc.language.iso | en | |
| dc.rights | Available to the World Wide Web | |
| dc.subject | mountain goat | |
| dc.subject | Oreamnos americanus | |
| dc.subject | weather | |
| dc.subject | climate | |
| dc.subject | snow | |
| dc.subject | avalanche | |
| dc.subject | mortality | |
| dc.subject | reproduction | |
| dc.subject | life-history | |
| dc.subject | population | |
| dc.subject | modeling | |
| dc.subject | conservation | |
| dc.subject | climate change | |
| dc.subject | sentinel species | |
| dc.title | Population ecology of mountain goats in relation to climate, weather and snow avalanches | |
| dc.type | Thesis |