Social variety in the yellow bellied marmot: a population behavioural system.

This is the publisher's version, which can also be found at: http://www.sciencedirect.com/science/article/pii/000334727790108

Transient LTRE analysis reveals the demographic and trait-mediated processes that buffer population growth.

Temporal variation in environmental conditions affects population growth directly via its impact on vital rates, and indirectly through induced variation in demographic structure and phenotypic trait distributions. We currently know very little about how these processes jointly mediate population responses to their environment. To address this gap, we develop a general transient life table response experiment (LTRE) which partitions the contributions to population growth arising from variation in (1) survival and reproduction, (2) demographic structure, (3) trait values and (4) climatic drivers. We apply the LTRE to a population of yellow-bellied marmots (Marmota flaviventer) to demonstrate the impact of demographic and trait-mediated processes. Our analysis provides a new perspective on demographic buffering, which may be a more subtle phenomena than is currently assumed. The new LTRE framework presents opportunities to improve our understanding of how trait variation influences population dynamics and adaptation in stochastic environments

Environmentally induced phenotypic variation in wild yellow-bellied marmots

We thank all the marmoteers who helped in data collection and 2 anonymous reviewers who helped us to clarify our message. AM-C was supported by a Fulbright Fellowship, and JGAM was supported by Fond Québécois de Recherche sur la Nature et les Technologies. KBA was supported by the National Science Foundation between 1962 and 2000. DTB was supported by the National Geographic Society, UCLA (Faculty Senate and the Division of Life Sciences), a Rocky Mountain Biological Laboratory research fellowship, and by the National Science Foundation (IDBR-0754247 and DEB-1119660 to DTB as well as DBI 0242960 and 0731346 to the Rocky Mountain Biological Laboratory).Peer reviewedPostprin

Weather influences on demography of the yellow-bellied marmot (Marmota flaviventris)

Yellow-bellied marmots Marmota flaviventris were live-trapped and marked in the Ea-q River Valley of Colorado from 1962 to 1998. For females, static life tables were calculated each year from 1967, when ages were well known to 1997. Population density was determined, and from life tables calculations were made of. survivorship of young yearlings and adults, percentage of females producing litters; mean and variance of litter size: net reproductive rate(R-o); and generation length. From climate records a set of 14 annual weather variables was developed that described temperature, precipitation and lengths of growing season and winter. Data from 1981 and 1996 were not used since weather data contained extreme outliers in date of last snow cover. Univariate correlation matrices were calculated among weather variables, among demographic variables, and between weather and demographic variables. Mean temperature in 24 of 29 years was cooler than long-term average temperature. Generation length increased during the years of the study Weather data were used as independent variables with each dependent demographic variable to calculate nine multiple correlation and regression models. Models explained from 0% to 58% of the variation in demography. Significant factors in each model were mostly interpreted as affecting availability of energy necessary for successful hibernation and reproduction

Harmonic errors associated with the use of choppers in optical experiments.

Rotating chopper wheels are used to modulate optical radiation in many experimental systems, typically for measuring the frequency response of an optical system. The assumption is often made that the chopped radiation varies sinusoidally. In practice, the radiation may have a square wave profile. This introduces high frequency harmonics that can distort the results of frequency measurements, particularly at low frequencies. Furthermore, the use of chopper wheels with different numbers of slots in order to cover different frequency ranges can introduce further effects. A simple change to the experimental set-up can produce a signal that has an approximately trapezoidal profile. Although not an ideal sine wave, we show that the trapezoidal modulation produces a much smaller error than for square wave modulation. In our case, the measurements are applied to the frequency response of pyroelectric infrared detectors, though the results are applicable to more general measurements on optical systems

Cumulative reproductive costs on current reproduction in a wild polytocous mammal

Funding Information Marie‐Curie Fellowship UCLA Rocky Mountain Biological Laboratory Research Fellowship NSF. Grant Numbers: IDBR‐0754247, DEB‐1119660, DBI 0242960, DBI 0731346 Natural Environment Research Council. Grant Number: NE/L50175X/1 National Geographic SocietyPeer reviewedPublisher PD

From Isotopes to TK Interviews: Towards Interdisciplinary Research in Fort Resolution and the Slave River Delta, Northwest Territories

Evolving research in Fort Resolution and the Slave River Delta, Northwest Territories, aims to improve understanding of how the natural ecosystem functions and responds to various environmental stressors, as well as to enhance the stewardship of natural resources and the capacity of local residents to respond to change. We seek to integrate approaches that span the natural and social sciences and traditional knowledge understandings of change, employing a research design developed in response to the concerns of a northern community. In doing so, we have strived for a research process that is collaborative, interdisciplinary, policy-oriented, and reflective of northern priorities. These elements characterize the new northern research paradigm increasingly promoted by various federal funding agencies, northern partners, and communities. They represent a holistic perspective in the pursuit of solutions to address complex environmental and socioeconomic concerns about impacts of climate change and resource development on northern societies. However, efforts to fulfill the objectives of this research paradigm are associated with a host of on-the-ground challenges. These challenges include (but are not restricted to) developing effective community partnerships and collaboration and documenting change through interdisciplinary approaches. Here we provide an overview of the components that comprise our interdisciplinary research program and offer an accounting of our formative experiences in confronting these challenges

A 32-year demography of yellow-bellied marmots (Marmota flaviventris)

Yellow-bellied marmots Marmota flaviventris in the East River Valley of Colorado were live-trapped and individually marked annually from 1962 through 1993. These pooled data were used to produce a demography and life table for these years. Females had significantly better survivorship than males beyond the first-year age class, and the sex ratio became progressively female biased. The major mortality factors of predation and unsuccessful hibernation acted evenly on all age classes as shown by the constant rates of survivorship. The rate of senescence indicated that the probability of mortality did not increase with age. Females produced litters from ages 2 to 10 years. Mean litter size was 4.1 and did not differ among age classes. The female generation length of 4.49 years was 2.4 times the life expectancy and the median survivorship. The net reproductive rate (R-o) was 0.67, yet the population did not continually decline; adjustments to these data increased R-o to 0.85. Reproductive values (V-x) were approximately equal across the reproductive age classes. The polygynous mating system is both cause and effect of the demography. Marmot population size is affected by weather factors that influence reproduction and survival, by predation, and by movement into and out of the study area

From Isotopes to TK Interviews: Towards Interdisciplinary Research in Fort Resolution and the Slave River Delta, Northwest Territories

Evolving research in Fort Resolution and the Slave River Delta, Northwest Territories, aims to improve understanding of how the natural ecosystem functions and responds to various environmental stressors, as well as to enhance the stewardship of natural resources and the capacity of local residents to respond to change. We seek to integrate approaches that span the natural and social sciences and traditional knowledge understandings of change, employing a research design developed in response to the concerns of a northern community. In doing so, we have strived for a research process that is collaborative, interdisciplinary, policy-oriented, and reflective of northern priorities. These elements characterize the new northern research paradigm increasingly promoted by various federal funding agencies, northern partners, and communities. They represent a holistic perspective in the pursuit of solutions to address complex environmental and socioeconomic concerns about impacts of climate change and resource development on northern societies. However, efforts to fulfill the objectives of this research paradigm are associated with a host of on-the-ground challenges. These challenges include (but are not restricted to) developing effective community partnerships and collaboration and documenting change through interdisciplinary approaches. Here we provide an overview of the components that comprise our interdisciplinary research program and offer an accounting of our formative experiences in confronting these challenges.Des travaux de recherche en cours à Fort Resolution et dans le delta de la rivière des Esclaves, aux Territoires du Nord-Ouest, visent à mieux comprendre le fonctionnement de l’écosystème naturel, à réagir aux divers facteurs d’agression environnementaux ainsi qu’à rehausser la gérance des ressources naturelles et la capacité des habitants de la région à réagir au changement. Nous cherchons à intégrer des méthodes qui englobent les sciences naturelles et sociales et favorisent la compréhension du changement du point de vue des connaissances traditionnelles. Nous cherchons également à employer une méthodologie respectueuse des inquiétudes de la collectivité du Nord. Ce faisant, nous avons abouti à un processus de recherche caractérisé par la collaboration, l’interdisciplinarité et les politiques, processus qui tient également compte des priorités dans le Nord. Ces éléments définissent le nouveau paradigme de recherche dans le Nord qui est de plus en plus préconisé par divers organismes de subvention fédéraux, partenaires du Nord et collectivités. Ils représentent une perspective holistique en guise de solutions à des enjeux environnementaux et socioéconomiques complexes portant sur les incidences du changement climatique et de l’exploitation des ressources sur les sociétés du Nord. Toutefois, les efforts visant à concrétiser les objectifs de ce paradigme de recherche font face à une multitude de défis. Ces défis comprennent (mais sans s’y restreindre) la formation de partenariats efficaces avec les collectivités, des efforts de collaboration et la prise de notes sur les changements qui s’opèrent grâce à des méthodes interdisciplinaires. Ici, nous fournissons un aperçu des éléments de notre programme de recherche interdisciplinaire et donnons un aperçu de l’expérience formative qui a découlé de ces défis

Demographic consequences of changes in environmental periodicity

The fate of natural populations is mediated by complex interactions among vital rates, which can vary within and among years. Although the effects of random, among-year variation in vital rates have been studied extensively, relatively little is known about how periodic, nonrandom variation in vital rates affects populations. This knowledge gap is potentially alarming as global environmental change is projected to alter common periodic variations, such as seasonality. We investigated the effects of changes in vital-rate periodicity on populations of three species representing different forms of adaptation to periodic environments: the yellow-bellied marmot (Marmota flaviventer), adapted to strong seasonality in snowfall; the meerkat (Suricata suricatta), adapted to inter-annual stochasticity as well as seasonal patterns in rainfall; and the dewy pine (Drosophyllum lusitanicum), adapted to fire regimes and periodic post-fire habitat succession. To assess how changes in periodicity affect population growth, we parameterized periodic matrix population models and projected population dynamics under different scenarios of perturbations in the strength of vital-rate periodicity. We assessed the effects of such perturbations on various metrics describing population dynamics, including the stochastic growth rate, log λS. Overall, perturbing the strength of periodicity had strong effects on population dynamics in all three study species. For the marmots, log λS decreased with increased seasonal differences in adult survival. For the meerkats, density dependence buffered the effects of perturbations of periodicity on log λS. Finally, dewy pines were negatively affected by changes in natural post-fire succession under stochastic or periodic fire regimes with fires occurring every 30 years, but were buffered by density dependence from such changes under presumed more frequent fires or large-scale disturbances. We show that changes in the strength of vital-rate periodicity can have diverse but strong effects on population dynamics across different life histories. Populations buffered from inter-annual vital-rate variation can be affected substantially by changes in environmentally driven vital-rate periodic patterns; however, the effects of such changes can be masked in analyses focusing on inter-annual variation. As most ecosystems are affected by periodic variations in the environment such as seasonality, assessing their contributions to population viability for future global-change research is crucial.European Research Council Advanced Grant; H2020 Marie Skłodowska-Curie Actions; Mammal Research Institute, University of Pretoria; MAVA Foundation; Ministerio de Economía y Competitividad; National Geographic Society; U.S. National Science Foundation; Rocky Mountain Biological Laboratory research fellowship; Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung and UCLA (Faculty Senate and Division of Life Sciences).https://onlinelibrary.wiley.com/r/ecyhj2023Mammal Research Institut