Download or read book Effects of Weather and Projected Impacts of Climate Change on Adult and Juvenile Survival in a Song Sparrow Melospiza Melodia Population written by Kristen Elizabeth Dybala and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate change research has been largely focused on projecting changes in species' distributions, which have included projections of dramatic shifts and contractions in species' ranges. These projections suggest that many local populations will decline as species' range limits retreat, but they reveal little about the processes that may produce these declines and range shifts. A better understanding of these processes, and of the effects of climate change on local populations, may be obtained by projecting the changes in local demographic rates in response to climate change. I collaborated with biologists from PRBO Conservation Science to examine in detail the effects of weather and project the impacts of climate change on adult and juvenile survival rates in a Song Sparrow (Melospiza melodia) population at the Palomarin Field Station in central coastal California. In chapter 1, my co-authors and I examined multiple hypotheses for the direct and indirect effects of weather on adult and juvenile survival rates using a mark-recapture data set spanning 1979-2010. We found that a direct effect of winter weather had a strong effect on adult survival, while an indirect effect of prior winter weather had a strong effect on juvenile survival. As a result, in response to climate change, we projected a significant increase in mean adult survival and a smaller decline in mean juvenile survival. Our results underscore the importance of considering both direct and indirect effects of climate change, as well as the potential for mismatches in the responses of different life stages to changes in environmental conditions. This theme of mismatches in the responses of different life stages to environmental conditions was echoed in chapter 2, in which my co-authors and I examined differences in the survival of dependent and independent juveniles. We found that prior winter precipitation had a strong positive effect on the survival of independent juveniles, consistent with an influence on food availability and the results of chapter 1, but had little effect on the survival of dependent fledglings, who benefited from the foraging skills of their parents. The effect of prior winter precipitation on independent juveniles also contributed more to the total variation in juvenile survival than any other variable we considered. We concluded that the survival of independent juveniles is a major driver of annual variation in juvenile survival, and that identifying the effects of weather on the survival of independent juveniles will be essential to understanding and projecting responses to climate change. Although the survival of dependent fledglings is less sensitive to environmental conditions than independent fledglings, survival was lowest during this stage, forming a critical bottleneck in the population dynamics. In chapter 3, I examined individual factors influencing survival during the dependent, post-fledging stage. I conducted a 3-year radio-telemetry study on the post-fledging survival of juvenile Song Sparrows, and used this data to examine two hypotheses for the mechanism behind the often-reported relationship between nestling body condition and post-fledging survival: (1) the frequently-proposed body fat hypothesis, in which nestlings that are relatively heavy for their size have more body fat and are more able to cope with temporary food shortages; and (2) the mobility hypothesis, in which relatively heavy nestlings have heavier, more developed muscles and are more mobile at fledging, making them better able to escape predation. I found little support for the body fat hypothesis, and strong support for the effect of fledgling mobility on post-fledging survival. However, nestling body condition was not related to fledgling mobility. I concluded that because body condition scores may integrate the varying effects of multiple underlying factors, identifying effect of body condition on post-fledging survival may not be as informative as directly assessing the effects of functional traits, such as mobility, and that variation in fledgling development has a strong influence on post-fledging survival. This detailed investigation of the sources of variation in survival provided insights into the ecological differences between adults and juveniles, and between dependent and independent juveniles. Understanding which life stages are most affected by which individual and environmental factors is essential to developing effective conservation plans, including climate change adaptation plans. For example, although this Song Sparrow population overall may respond positively to climate change, this approach will be useful in other populations for identifying the demographic process(es) that will be adversely affected by climate change, and the mechanisms that may be responsible, such as the effect of drier conditions on food availability and the subsequent survival of independent juveniles. This information can in turn help prioritize future research and indicate management actions that may be effective in slowing or mitigating the effects of climate change for a population of concern.

Download or read book Effects of Climate Change on Birds written by Anders Pape Møller and published by OUP Oxford. This book was released on 2010-08-12 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate change affects all living organisms; it has done so in the past and will do so in the future. However, current climate change is exceptional both in terms of the rate of change and the impact of multiple types of global change on individuals, populations, species, and ecosystems. Effects of Climate Change on Birds provides an exhaustive and up-to-date synthesis of the science of climate change as it relates to birds. Compared with any other class of animals, birds provide more long-term data and extensive time series (some dating back more than 100 years), a more geographically and taxonomically diverse source of information, and a longer tradition of extensive research. In fact this research record exceeds what is available in all other organisms combined.

Download or read book Climatic Variability and Climate Change written by Sara Elizabeth Harrod and published by . This book was released on 2020 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite the scientific consensus that human activities are the primary cause, many people deny the problem of climate change. If mitigation efforts are to be successful, we need to determine young individuals' attitudes toward and knowledge of climate change. Successful mitigation efforts are important for humans, as well as wildlife and the environment. Wildlife populations are already being affected, with many documented cases of negative impacts. Effects on populations can occur through impacts on demographic parameters, and if parameters are synchronized across species or populations, this could prove disastrous if climate change negatively affects these parameters. Here, I surveyed first-semester college students from 19 universities across the United States to assess their attitudes and knowledge toward climate change, determine what affected these variables, and test for a relationship between attitude and knowledge. I also used nesting and banding data from 4 populations of Eastern Bluebirds (Sialia sialis) in contrasting climatic regions to estimate each population's demographic parameters, determine which global climatic and local weather variable affected these parameters, and project how populations in each region will be impacted under future climate change scenarios. Finally, I used 21 years of nesting data collected by citizen scientists to assess whether the breeding parameters of 4 cavity nesting songbirds were synchronized. I found that attitude and knowlege were positively associated, and approximately the same combination of personal and environmental factors affected student knowledge and attitude. I also found that across all Eastern Bluebird populations, breeding parameter estimates were relatively high, whereas adult and juvenile survival estimates were low. These parameters were affected by multiple global and local climatic variables throughout the breeding and non-breeding seasons, with the exact variables differing among populations. Western populations mostly benefited under climate change scenarios, but eastern populations showed declines in population growth rates. Finally, I found little evidence of synchrony in breeding parameters, which may have been due to lack of data, and I recommend increasing citizen-science efforts. Overall, my results suggest a more promising future than expected for some species like Eastern Bluebirds, with the next generation of citizens showing increased concern about climate change.

Download or read book The Impact of Weather on the Behavior and Ecology of Birds written by Stuart Peter Sharp and published by Frontiers Media SA. This book was released on 2021-12-29 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Environmental Influence on the Ontogeny Allometry and Behavior of the Song Sparrow Melospiza Melodia written by Julia Irene Smith and published by . This book was released on 1993 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ecology Behavior and Trophic Adaptations of the Salt Marsh Song Sparrow Melospiza Melodia Samuelis written by Jill Letitia Grenier and published by . This book was released on 2004 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Relationship Between Predation Pressure Demography and Genetic Diversity in Song Sparrow Melospiza Melodia Populations written by Michelle Emily Bondy and published by . This book was released on 2012 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: While the impacts of predators on prey demography are well studied, relatively few studies have explored how predators affect the population genetics of prey. I investigated the effects of predation pressure on genetic diversity and genetic similarity in song sparrows (Melospiza melodia) and the demographic mechanisms (births, deaths and dispersal) that may drive this relationship. I compared genetic diversity and genetic similarity (measured at 13 neutral microsatellite loci) between landscapes (island and mainland), and between populations within each landscape. In every comparison, sparrows inhabiting the landscape or population with higher nest predation were more related to one another, and in one comparison, had lower genetic diversity. High nest predation also was associated with reduced birth and population growth rates, and increased variance in reproductive success. Thus, the effects predators have on prey demography may negatively impact the genetic diversity of prey populations, beyond their effects on prey population size.

Download or read book The Effects of Habituation on Boldness of Urban and Rural Song Sparrows Melospiza Melodia written by Taylor Elaine Fossett and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: As urban development continues to dominate landscapes across the United States, wildlife species are changing their behavior in many ways. Urban animals are often bolder, or less fearful of new stimuli, than rural animals. While natural selection and adaptation can drive behavioral changes in urban animals, other factors, such as learning or habituation, can also lead to behavioral modifications. Habituation may play an important role, if urban individuals learn through repeated exposure that humans do not represent a threat. To determine how repeated human exposure affects song sparrow (Melospiza melodia) populations in an urban and rural habitat, I measured boldness as flight initiation distance (FID), after repeated exposure to a nonthreatening human subject. FID measures the distance between human and bird, at which the bird flies away in fear of disturbance or predation. I collected FID data on male song sparrows in an urban and rural environment over 5 consecutive days. I found that after 5 days of successive trials, FID was individually repeatable in both urban and rural populations. Urban birds had consistently lower FID than their rural counterparts. I also found that FID went down over 5 days of repeated trials in the rural populations, but not the urban. These results suggest that habituation can occur quickly in rural birds and account for the greater boldness we typically see in urban populations.

Download or read book A Temporally Explicit Investigation of the Effects of Habitat Change on Landbird Population and Community Dynamics written by Elizabeth Laura Porzig and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Studying population and community dynamics through time provides a better understanding of the ecological impacts of increasing rates of anthropogenic change. Such investigations can (1) validate the tools we use to understand and predict the impacts of environmental dynamics, (2) identify dominant processes affecting populations and communities, and (3) provide insight into the mechanisms of population response to environmental change. Here, I use long-term data from the Palomarin Field Station in coastal California detailing three decades of landbird population and community dynamics at a site undergoing secondary plant succession to better understand the effects of environmental change on landbirds. In Chapter 1, I compare the ability of a habitat suitability models (HSMs) to logistic population models to explain and predict trends in abundance of seven species. HSMs are increasingly used to predict species response to future climate and land-use scenarios. However, these models do not explicitly incorporate time-dependent processes such as population growth rates and the strength of density dependence. I compared HSMs to logistic population models in explaining and predicting landbird response to vegetation change at Palomarin. In the retrospective comparison, I found that HSMs performed well in explaining variation in trends of the seven species over a 23-year period from 1983-2005, explaining between 58 and 90% of deviance. However, for three of the species, Song Sparrow (Melospiza melodia), White-crowned Sparrow (Zonotrichia leucophrys), and Wrentit (Chamaea fasciata), a logistic population model provided a better fit to the retrospective data. These three species have more localized dispersal, suggesting that incorporating population processes into habitat suitability modeling for species with similar dispersal patterns may improve projections. In the prospective evaluation, I used both model types to predict changes in abundance from 2006-2010, and I compared these predicted abundances to the observed abundances. Neither model type performed consistently better in predicting species trends over the five year period. In summary, I found that overall HSMs can explain and predict species' trends through time; however, for species with localized dispersal, incorporating population processes may improve understanding. There is strong evidence that differential response of species to changes in the environment will result in novel community assemblages. An unresolved question is the degree to which interspecific interactions influence long-term changes in populations, since most analyses have considered species responses to occur independently of the community in which they occur. In the Chapter 2, I applied a hierarchical approach and Bayesian inference to the times series of seven species used in my first chapter to partition variance in species trends between interspecific interactions, intraspecific processes and environmental forcing. I found that within-guild interspecific interactions were the least important contributor to variation in species trends, explaining between 0 and 5% of variation. Vegetation and rainfall variation, combined, explained 6 to 30% of variation in species trends. Intraspecific processes explained between 0 and 39% of variation. Between 27 to 90% of variation was attributed to unexplained variation. While these are not novel species interactions, as would be expected in communities resulting from anthropogenic change, these results suggest that within-guild interactions are not a major source of variation in landbird population trends. In the third chapter of my dissertation, I investigated the underlying behavioral and demographic mechanisms of species' response to environmental dynamics. I focus on one species, White-crowned Sparrow, which has declined dramatically in density since 1980. I evaluate patterns in vegetation change, nest site selection, and three measures of reproductive success to understand the effect of habitat change on individuals and to provide insight into the degree to which White-crowned Sparrows are able to ameliorate the effects of habitat change through behavioral decisions. I found that White-crowned Sparrows prefer early successional habitat, and no evidence for an effect of the range of experienced habitat conditions on variation in nest survival, clutch size, or number of fledglings. These results provide evidence that through their strong habitat preference, individual White-crowned Sparrows are able to narrow the range of successional habitat they experience, and thus do not incur a demographic cost of habitat change on reproductive success. These results demonstrate the species' ability to adjust to habitat change through behavioral decisions. As we recognize the degree to which anthropogenic forcing creates environmental change, we are increasingly aware that the impact of these changes will depend in part upon the rate at which they occur. By explicitly studying landbird population and community response to three decades of habitat change, this dissertation provides insight into the ecological processes that influence variation in population abundances, the mechanisms underlying species' response to environmental change, and the efficacy of the tools we use to study and predict these responses. My findings that (1) HSMs perform well in explaining variation in species trends through time, (2) interspecific interactions are not a dominant driver of trends, and (3) habitat selection decisions can ameliorate the negative effects of habitat change on reproductive success provide a baseline of understanding to which we can compare changes in other systems and at other time scales in order to better understand and explain ecological change in a time of increasing rates of change and increasing variability.

Download or read book Life in a Changing World written by Nina Margaret McLean and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anthropogenic climate change is predicted to be a major cause of extinctions. Therefore, a major aim of climate change ecology is to understand how species are being impacted and identify which species are most at risk. However, the ability to make these broad generalisations requires large-scale comparative analyses based on appropriate assumptions. This thesis investigates how European birds respond to changes in climate, the validity of several common assumptions, and identifies which species or populations are most at risk based on multiple long-term datasets. Our understanding of how different responses relate and how they affect population persistence is lacking. A conceptual hierarchical framework is introduced in chapter one to better understand and predict when climate-induced trait changes (phenology or physiology) impact demographic rates (survival or reproduction), and subsequently population dynamics. I synthesise the literature to find hypotheses about life-history and ecological characteristics that could predict when population dynamics will likely be affected. An example shows that, although earlier laying with warmer temperatures was associated with improved reproduction, this had no apparent effect on population trends in 35 British birds. Number of broods partly explains which species are most at risk of temperature-induced population declines. It is often assumed that populations within species respond similarly to climate change, and therefore a single value will reflect species-specific responses. Chapter two explores inter- and intra-specific variation in body condition responses to six climatic variables in 46 species over 21 years and 80 sites. Body condition is sensitive to all six variables (primarily in a non-linear way), and declines with warmer temperatures. I find that species signals might not exist as populations of the same species are no more alike than populations of different species. Decreased body condition is typically assumed to have detrimental consequences on species' vital rates and population dynamics, but this assumption has rarely been tested. Expanding on chapter two, chapter three shows that temperature-induced declines in body condition have no apparent consequences on demography and population dynamics. Instead, temperature has strong effects on reproductive success and population growth rates via unknown traits and demographic rates. Much of the literature investigating climatic impacts assumes that temporal trends accurately reflect responses to climate change, and therefore investigate trait changes over time. In chapter four, I use two long-term datasets to demonstrate that, for four different types of trait responses, trait variation through time cannot be assumed to be due to warming. Non-temperature causal agents are important in explaining temporal trends, often resulting in reinforced effects. Consequently, the roles of climatic and non-climatic effects need to be understood to better predict those species most at risk. This thesis lays the foundations for more holistic climate change research that encompasses relationships among multiple response types, species and populations. Such knowledge will be vital for future conservation efforts.

Download or read book Predictors of Juvenile Survival in Birds written by Terri J. Maness and published by . This book was released on 2013 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: The survival probability of birds during the juvenile period, between the end of parental care and adulthood, is highly variable and has a major effect on population dynamics and parental fitness. As such, a large number of studies have attempted to evaluate potential predictors of juvenile survival in birds, especially predictors related to parental care. Lack's hypothesis linking body reserves accumulated from parental care to the survival of naive juveniles has organized much of this research, but various other predictors have also been investigated and received some support. We reviewed the literature in this area and identified a variety of methodological problems that obscure interpretation of the body of results. Most studies adopted statistical techniques that missed the opportunities to (1) evaluate the relative importance of several predictors, (2) control the confounding effect of correlation among predictor variables, and (3) exploit the information content of collinearity by evaluating indirect (via correlation) as well as direct effects of potential predictors on juvenile survival. Ultimately, we concluded that too few reliable studies exist to allow robust evaluations of any hypothesis regarding juvenile survival in birds. We used path analysis to test potential predictors of juvenile survival of 2,631 offspring from seven annual cohorts of a seabird, the Nazca Booby (Sula granti). Fledging age was the most important predictor of juvenile survival: fast-growing offspring survived best, when all other variables were held constant. Offspring sex was the next most important predictor, with juvenile males (the smaller sex) surviving better than females. Hatching day, an index of body weight, and wing length also showed important predictive ability, but cohort size, culmen length, and an index of clutch size and hatching success did not. Nestling growth was compromised under poor rearing conditions: overall weight fell, the number of days needed to reach fledging status increased, and the growth of some structures, but not others, was reduced. These effects were more pronounced in females, and the higher juvenile mortality of females accounts for most of the male bias in the adult sex ratio and its attendant "mate rotation" mating system in this population. Most previous studies did not evaluate sex as a potential predictor of juvenile survival. Had we omitted sex from our models, we would have made two erroneous conclusions: that weight did not influence juvenile survival, and that small structural size enhanced it.--

Download or read book Indicators of Climate Change in California written by Carmen Milanes (Environmentalist) and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Public Health Significance of Urban Pests written by Xavier Bonnefoy and published by World Health Organization. This book was released on 2008 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second half of the 20th century and the beginning of the 21st century witnessed important changes in ecology, climate and human behaviour that favoured the development of urban pests. Most alarmingly, urban planners now face the dramatic expansion of urban sprawl, in which city suburbs are growing into the natural habitats of ticks, rodents and other pests. Also, many city managers now erroneously assume that pest-borne diseases are relics of the past. All these changes make timely a new analysis of the direct and indirect effects of present-day urban pests on health. Such an analysis should lead to the development of strategies to manage them and reduce the risk of exposure. To this end, WHO invited international experts in various fields - pests, pest-related diseases and pest management - to provide evidence on which to base policies. These experts identified the public health risk posed by various pests and appropriate measures to prevent and control them. This book presents their conclusions and formulates policy options for all levels of decision-making to manage pests and pest-related diseases in the future. [Ed.]

Download or read book The Flexible Phenotype written by Theunis Piersma and published by Oxford University Press. This book was released on 2011 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: In essence, the authors argue for the existence of direct, measurable, links between phenotype and ecology.

Download or read book Current Ornithology Volume 17 written by Charles F. Thompson and published by Springer Science & Business Media. This book was released on 2010-09-09 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current Ornithology publishes authoritative, up-to-date, scholarly reviews of topics selected from the full range of current research in avian biology. Topics cover the spectrum from the molecular level of organization to population biology and community ecology. The series seeks especially to review (1) fields in which an abundant recent literature will benefit from synthesis and organization, or (2) newly emerging fields that are gaining recognition as the result of recent discoveries or shifts in perspective, or (3) fields in which students of vertebrates may benefit from comparisons of birds with other classes. All chapters are invited, and authors are chosen for their leadership in the subjects under review.

Download or read book California Bird Species of Special Concern written by and published by . This book was released on 2008 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monitoring Animal Populations and Their Habitats written by Brenda McComb and published by CRC Press. This book was released on 2010-03-11 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the face of so many unprecedented changes in our environment, the pressure is on scientists to lead the way toward a more sustainable future. Written by a team of ecologists, Monitoring Animal Populations and Their Habitats: A Practitioner’s Guide provides a framework that natural resource managers and researchers can use to design monitoring programs that will benefit future generations by distilling the information needed to make informed decisions. In addition, this text is valuable for undergraduate- and graduate-level courses that are focused on monitoring animal populations. With the aid of more than 90 illustrations and a four-page color insert, this book offers practical guidance for the entire monitoring process, from incorporating stakeholder input and data collection, to data management, analysis, and reporting. It establishes the basis for why, what, how, where, and when monitoring should be conducted; describes how to analyze and interpret the data; explains how to budget for monitoring efforts; and discusses how to assemble reports of use in decision-making. The book takes a multi-scaled and multi-taxa approach, focusing on monitoring vertebrate populations and upland habitats, but the recommendations and suggestions presented are applicable to a variety of monitoring programs. Lastly, the book explores the future of monitoring techniques, enabling researchers to better plan for the future of wildlife populations and their habitats. Monitoring Animal Populations and Their Habitats: A Practitioner’s Guide furthers the goal of achieving a world in which biodiversity is allowed to evolve and flourish in the face of such uncertainties as climate change, invasive species proliferation, land use expansion, and population growth.