Ecology
Permanent URI for this communityhttps://scholarworks.montana.edu/handle/1/44
The department's teaching and research addresses critical ecological and natural resources issues for Montana, but also tackles fundamental and applied questions around the globe.
Undergraduate programs within the department include Fish & Wildlife Management and Ecology, Conservation Biology and Ecology, Organismal Biology, and Biology Teaching. Graduate programs (M.S. and P.hD.) include Fish & Wildlife Management or Biology and Biological Sciences and an intercollege PhD in Ecology and Environmental Sciences.
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Item Yellowstone Cutthroat Trout Recovery in Yellowstone Lake: Complex Interactions Among Invasive Species Suppression, Disease, and Climate Change(Wiley, 2023-10) Glassic, Hayley C.; Chagaris, David D.; Guy, Christopher S.; Tronstad, Lusha M.; Lujan, Dominque R.; Briggs, Michelle A.; Albertson, Lindsey K.; Brenden, Travis O.; Walsworth, Timothy E.; Koel, Todd M.n Yellowstone Lake, Wyoming, the largest inland population of nonhybridized Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri, hereafter Cutthroat Trout, declined throughout the 2000s because of predation from invasive Lake Trout Salvelinus namaycush, drought, and whirling disease Myxobolus cerebralis. To maintain ecosystem function and conserve Cutthroat Trout, a Lake Trout gill netting suppression program was established in 1995, decreasing Lake Trout abundance and biomass. Yet, the response of Cutthroat Trout to varying Lake Trout suppression levels, collectively with the influence of disease and climate, is unknown. We developed an ecosystem model (calibrated to historical data) to forecast (2020–2050) whether Cutthroat Trout would achieve recovery benchmarks given disease, varying suppression effort, and climate change. Lake Trout suppression influenced Cutthroat Trout recovery; current suppression effort levels resulted in Cutthroat Trout recovering from historical lows in the early 2000s. However, Cutthroat Trout did not achieve conservation benchmarks when incorporating the influence of disease and climate. Therefore, the National Park Service intends to incorporate age‐specific abundance, spawner biomass, or both in conservation benchmarks to provide better indication of how management actions and environmental conditions influence Cutthroat Trout. Our results illustrate how complex interactions within an ecosystem must be simultaneously considered to establish and achieve realistic benchmarks for species of conservation concern.Item Measuring Understory Fire Effects from Space: Canopy Change in Response to Tropical Understory Fire and What This Means for Applications of GEDI to Tropical Forest Fire(MDPI, 2023-01) East, Alyson; Hansen, Andrew; Armenteras, Dolors; Jantz, Patrick; Roberts, David W.The ability to measure the ecological effects of understory fire in the Amazon on a landscape scale remains a frontier in remote sensing. The Global Ecosystem Dynamics Investigation’s (GEDI) LiDAR data have been widely suggested as a critical new tool in this field. In this paper, we use the GEDI Simulator to quantify the nuanced effects of understory fire in the Amazon, and assess the ability of on-orbit GEDI data to do the same. While numerous ecological studies have used simulated GEDI data, on-orbit constraint may limit ecological inference. This is the first study that we are aware of that directly compares methods using simulated and on-orbit GEDI data. Simulated GEDI data showed that fire effects varied nonlinearly through the canopy and then moved upward with time since burn. Given that fire effects peaked in the mid-canopy and were often on the scale of 2 to 3 m in height difference, it is unlikely that on-orbit GEDI data will have the sensitivity to detect these same changes.Item Effects of de-snaring on the demography and population dynamics of African lions(Elsevier BV, 2023-10) Banda, Kambwiri; Creel, Scott; Sichande, Mwamba; Mweetwa, Thandiwe; Mwape, Henry; Reyes de Merkle, Johnathan; Mwansa Bwalya, Lengwe; Simpamba, Twakundine; McRobb, Rachel; Becker, Matthew S.Lions and other African large carnivores are in decline, due in part to effects of illegal hunting with snares, which can reduce prey availability and directly kill or injure carnivores. It is difficult to effectively remove snares from large ecosystems by patrolling, but an additional approach to reduce effects on large carnivores is to monitor the population closely and de-snare individuals who are found in a snare or have broken free but still carry the wire (often with serious injury). The effectiveness of de-snaring programs to reduce impacts on large carnivores has not been directly tested. Here, we used long-term demographic data from 386 individually identified lions in the Luangwa Valley Ecosystem to test the effects on population growth (λ) and population size (N) of a program to remove snares from injured lions and treat their wounds. Stochastic Leslie matrix projections for a period of five years showed that the population grew with the benefits of de-snaring, but was expected to decline without de-snaring. Mean annual growth (λ) with de-snaring was 1.037 (with growth in 70% of years), closely matching observed changes in population size. Mean annual growth was 0.99 (with growth in 47% of years) for a model that assumed snared animals would have died if not treated, and 0.95 (with growth in 37% of years) for models that also accounted for super-additive effects via the death of dependent cubs and increased infanticide with increased male mortality. De-snaring requires intensive effort, but it can appreciably reduce the effect of snaring on lion population dynamics.Item The geography of climate and the global patterns of species diversity(Springer Science and Business Media LLC, 2023-09) Coelho, Marco Túlio P.; Barreto, Marco Túlio P.; Barreto, Elisa; Rangel, Thiago F.; Diniz-Filho, José Alexandre F.; Wüest, Rafael O.; Bach, Wilhelmine; Skeels, Alexander; McFadden, Ian R.; Roberts, David W.; Pellissier, Loïc; Zimmermann, Niklaus E.; Graham, Catherine H.Climate’s effect on global biodiversity is typically viewed through the lens of temperature, humidity and resulting ecosystem productivity1,2,3,4,5,6. However, it is not known whether biodiversity depends solely on these climate conditions, or whether the size and fragmentation of these climates are also crucial. Here we shift the common perspective in global biodiversity studies, transitioning from geographic space to a climate-defined multidimensional space. Our findings suggest that larger and more isolated climate conditions tend to harbour higher diversity and species turnover among terrestrial tetrapods, encompassing more than 30,000 species. By considering both the characteristics of climate itself and its geographic attributes, we can explain almost 90% of the variation in global species richness. Half of the explanatory power (45%) may be attributed either to climate itself or to the geography of climate, suggesting a nuanced interplay between them. Our work evolves the conventional idea that larger climate regions, such as the tropics, host more species primarily because of their size7,8. Instead, we underscore the integral roles of both the geographic extent and degree of isolation of climates. This refined understanding presents a more intricate picture of biodiversity distribution, which can guide our approach to biodiversity conservation in an ever-changing world.Item Equity, community, and accountability: Leveraging a department-level climate survey as a tool for action(Public Library of Science, 2023-08) Barrile, Gabriel M.; Bernard, Riley F.; Wilcox, Rebecca C.; Becker, Justine A.; Dillon, Michael E.; Thomas-Kuzilik, Rebecca R.; Bombaci, Sara P.; Merkle, Bethann GarramonOrganizational climate is a key determinant of diverse aspects of success in work settings, including in academia. Power dynamics in higher education can result in inequitable experiences of workplace climate, potentially harming the well-being and productivity of employees. Quantifying experiences of climate across employment categories can help identify changes necessary to create a more equitable workplace for all. We developed and administered a climate survey within our academic workplace—the Department of Zoology and Physiology at the University of Wyoming—to evaluate experiences of climate across three employment categories: faculty, graduate students, and staff. Our survey included a combination of closed-response (e.g., Likert-scale) and open-ended questions. Most department members (82%) completed the survey, which was administered in fall 2021. Faculty generally reported more positive experiences than staff. Graduate students often fell between these two groups, though in some survey sections (e.g., mental health and well-being) students reported the most negative experiences of departmental climate. Three common themes emerged from the analysis of open-ended responses: equity, community, and accountability. We discuss how these themes correspond to concrete action items for improving our departmental climate, some of which have been implemented already, while others constitute future initiatives and/or require a collective push towards systemic change in academia. Finally, service work of this type often falls outside of job descriptions, requiring individuals to either work more or trade-off productivity in other areas that are formally evaluated. With the goal of minimizing this burden for others, we detail our process and provide the materials and framework necessary to streamline this process for other departments aiming to evaluate workplace climate as a key first step in building a positive work environment for all employees.Item Individual life histories: neither slow nor fast, just diverse(The Royal Society, 2023-07) Van de Walle, Joanie; Fay, Rémi; Gaillard, Jean-Michel; Pelletier, Fanie; Hamel, Sandra; Gamelon, Marlène; Barbraud, Christophe; Blanchet, F. Guillaume; Blumstein, Daniel T.; Charmantier, Anne; Delord, Karine; Larue, Benjamin; Martin, Julien; Mills, James A.; Milot, Emmanuel; Mayer, Francine M.; Rotella, Jay; Saether, Bernt-Erik; Teplitsky, Céline; van de Pol, Martijn; Van Vuren, Dirk H.; Visser, Marcel E.; Wells, Caitlin P.; Yarrall, John; Jenouvrier, StéphanieThe slow–fast continuum is a commonly used framework to describe variation in life-history strategies across species. Individual life histories have also been assumed to follow a similar pattern, especially in the pace-of-life syndrome literature. However, whether a slow–fast continuum commonly explains life-history variation among individuals within a population remains unclear. Here, we formally tested for the presence of a slow–fast continuum of life histories both within populations and across species using detailed long-term individual-based demographic data for 17 bird and mammal species with markedly different life histories. We estimated adult lifespan, age at first reproduction, annual breeding frequency, and annual fecundity, and identified the main axes of life-history variation using principal component analyses. Across species, we retrieved the slow–fast continuum as the main axis of life-history variation. However, within populations, the patterns of individual life-history variation did not align with a slow–fast continuum in any species. Thus, a continuum ranking individuals from slow to fast living is unlikely to shape individual differences in life histories within populations. Rather, individual life-history variation is likely idiosyncratic across species, potentially because of processes such as stochasticity, density dependence, and individual differences in resource acquisition that affect species differently and generate non-generalizable patterns across species.Item Connectivity between white shark populations off Central California, USA and Guadalupe Island, Mexico(Frontiers Media SA, 2023-07) Kanive, Paul E.; Rotella, Jay J.; Chapple, Taylor K.; Anderson, Scot D.; Hoyos-Padilla, Mauricio; Klimley, Abbott Peter; Galván-Magaña, Felipe; Andrzejaczek, Samantha; Block, Barbara A.; Jorgensen, Salvador J.Marine animals often move beyond national borders and exclusive economic zones resulting in a need for trans-boundary management spanning multiple national jurisdictions. Highly migratory fish vulnerable to over-exploitation require protections at international level, as exploitation practices can be disparate between adjacent countries and marine jurisdictions. In this study we collaboratively conducted an analysis of white shark connectivity between two main aggregation regions with independent population assessment and legal protection programs; one off central California, USA and one off Guadalupe Island, Mexico. We acoustically tagged 326 sub-adult and adult white sharks in central California (n=210) and in Guadalupe Island (n=116) with acoustic transmitters between 2008-2019. Of the 326 tagged white sharks, 30 (9.20%) individuals were detected at both regions during the study period. We used a Bayesian implementation of logistic regression with a binomial distribution to estimate the effect of sex, maturity, and tag location to the response variable of probability of moving from one region to the other. While nearly one in ten individuals in our sample were detected in both regions over the study period, the annual rate of trans-regional movement was low (probability of movement = 0.015 yr-1, 95% credible interval = 0.002, 0.061). Sub-adults were more likely than adults to move between regions and sharks were more likely to move from Guadalupe Island to central California, however, sex, and year were not important factors influencing movement. This first estimation of demographic-specific trans-regional movement connecting US and Mexico aggregations with high seasonal site fidelity represents an important step to future international management and assessment of the northeastern Pacific white shark population as a whole.Item A hypothetico‐deductive theory of science and learning(Wiley, 2023-08) Kalinowski, Steven T.; Pelakh, AvitalThis article presents a simple, cognitive theory of science and learning. The first section of the paper develops the theory's two main propositions: (i) A wide range of scientific activities rely heavily on one type of reasoning, hypothetical thinking, and (ii) This type of reasoning is also useful to students for learning science content. The second section of the paper presents a taxonomy of multiple‐choice questions that use hypothetical thinking and the third section of the paper tests the theory using data from a college biology course. As expected by the theory, student responses to 24 scientific reasoning questions were consistent with a one‐dimensional psychometric construct. Student responses to the scientific reasoning questions explained 36% of the variance in exam grades. Several directions for additional research are identified, including studying the psychometric structure of scientific thinking in more detail, performing randomized, controlled experiments to demonstrate a causal relationship between scientific thinking and learning, and identifying the relative contribution of other factors to success in college.Item Lead, trash, DDE, and young age of breeders linked to lower fertility in the first two decades of reintroduction for critically endangered California Condors in California(Oxford Academic, 2023-08) Bakker, Victoria J.; Finkelstein, Myra E.; Doak, Daniel F.; Wolstenholme, Rachel; Welch, Alacia; Burnett, Joe; Punzalan, Arianna; Brandt, Joseph; Kirkland, Steve; Seal Faith, Nadya E.In the first comprehensive assessment of the reproductive rates of critically endangered California Condors (Gymnogyps californianus) recovering from complete extirpation in the wild, we analyzed 20 years (1999–2018) of data from condor flocks in southern and central California. We found that several anthropogenic threats affected reproductive rates: (1) coastal space use by female condors was associated with lower hatch probability, presumably due to foraging on marine mammals and associated DDE exposure; (2) trash ingestion by chicks decreased fledging probability prior to implementation of trash management in 2007; and (3) all parent deaths during rearing resulted in chick or early fledgling deaths, and most parental deaths were due to lead poisoning. We also detected several effects on reproductive rates from the complex individual-based management of condors, which involves ongoing releases of captive-bred individuals and health interventions including treatment of lead poisoning. Recruitment rates were lower for new release sites, which we attribute to a lack of individual- and flock-level experience. In addition, the number of free-flying days in the wild in the year before first breeding and in the 8 weeks before subsequent breeding was positively associated with female and male recruitment and with female rebreeding probabilities, respectively, indicating that removing individuals from the wild may reduce their breeding success. Finally, probabilities of recruitment, rebreeding, and fledging all increased with age, and given the age distribution skew of the recovering flocks toward younger individuals, overall reproductive success was lower than would be expected at the stable age distribution. Thus, reproductive rates should increase over time as the mean age of California Condors increases if current and emerging threats to reproduction, including the loss of breeders due to lead poisoning, can be addressed.Item Insect and Pathogen Influences on Tree-Ring Stable Isotopes(Springer Nature, 2022-06) Ulrich, Danielle E. M.; Voelker, Steve; Brooks, J. Renée; Meinzer, Frederick C.Understanding long-term insect and pathogen effects on host tree physiology can help forest managers respond to insect and pathogen outbreaks, and understand when insect and pathogen effects on tree physiology will be exacerbated by climate change. Leaf-level physiological processes modify the carbon (C) and oxygen (O) stable isotopic composition of elements taken up from the environment, and these modifications are recorded in tree-rings (see Chaps. 9, 10, 16 and 17). Therefore, tree-ring stable isotopes are affected by both the tree’s environment and the tree’s physiological responses to the environment, including insects and pathogens. Tree-ring stable isotopes provide unique insights into the long-term effects of insects and pathogens on host tree physiology. However, insect and pathogen impacts on tree-ring stable isotopes are often overlooked, yet can substantially alter interpretations of tree-ring stable isotopes for reconstructions of climate and physiology. In this chapter, we discuss (1) the effects of insects (defoliators, wood-boring, leaf-feeding), pests (parasitic plants), and pathogens (root and foliar fungi) on host physiology (growth, hormonal regulation, gas exchange, water relations, and carbon and nutrient use) as they relate to signals possibly recorded by C and O stable isotopes in tree-rings, (2) how tree-ring stable isotopes reveal insect and pathogen impacts and the interacting effects of pathogens and climate on host physiology, and (3) the importance of considering insect and pathogen impacts for interpreting tree-ring stable isotopes to reconstruct past climate or physiology.