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Full-Text Articles in Life Sciences

American White Pelicans, Tommy King May 2019

American White Pelicans, Tommy King

Wildlife Damage Management Technical Series

American white pelicans (Pelecanus erythrorhynchos, Figure 1) threaten aquaculture producers by direct predation and the spread of disease. They are also considered competition and a nuisance by some sports fishermen. Pelicans can also damage pond levees and crops, such as rice, by trampling the vegetation and depositing guano. A combination of wildlife damage management techniques is often necessary to reduce pelican damage to these resources. Aquaculture Prior to the winter of 1992, American white pelican depredations at catfish facilities in the Delta regions of Arkansas and Mississippi were limited, and birds were easily dispersed from the area. Since 1992, however ...


Systematics Of The Neotropical Genus Leptodactylus Fitzinger, 1826 (Anura: Leptodactylidae): Phylogeny, The Relevance Of Non-Molecular Evidence, And Species Accounts, Rafael O. De Sá, Taran Grant, Arley Camargo, W. R. Heyer, María Laura Ponssa, Edward Stanley Sep 2014

Systematics Of The Neotropical Genus Leptodactylus Fitzinger, 1826 (Anura: Leptodactylidae): Phylogeny, The Relevance Of Non-Molecular Evidence, And Species Accounts, Rafael O. De Sá, Taran Grant, Arley Camargo, W. R. Heyer, María Laura Ponssa, Edward Stanley

Biology Faculty Publications

A phylogeny of the species-rich clade of the Neotropical frog genus Leptodactylus sensu stricto is presented on the basis of a total evidence analysis of molecular (mitochondrial and nuclear markers) and non-molecular (adult and larval morphological and behavioral characters) sampled from > 80% of the 75 currently recognized species. Our results support the monophyly of Leptodactylus sensu stricto, with Hydrolaetare placed as its sister group. The reciprocal monophyly of Hydrolaetare and Leptodactylus sensu stricto does not require that we consider Hydrolaetare as either a subgenus or synonym of Leptodactylus sensu lato. We recognize Leptodactylus sensu stricto, Hydrolaetare, Adenomera, and Lithodytes as ...


Symbiont Presence And Identity Influence Life History Strategies Of A Temperate Sea Anemone, Brian L. Bingham, James L. Dimond, Gisele Muller-Parker Jun 2014

Symbiont Presence And Identity Influence Life History Strategies Of A Temperate Sea Anemone, Brian L. Bingham, James L. Dimond, Gisele Muller-Parker

Environmental Sciences Faculty and Staff Publications

Along the North American Pacific coast, the common intertidal sea anemone Anthopleura elegantissima engages in facultative, flexible symbioses with Symbiodinium muscatinei (a dinoflagellate) and Elliptochloris marina (a chloro- phyte). Determining how symbiotic state affects host fitness is essential to understanding the ecological significance of engaging in such flexible relationships with diverse symbionts. Fitness consequences of hosting S. muscatinei, E. marina or negligible numbers of either symbiont (aposymbiosis) were investigated by measuring growth, cloning by fission and gonad development after 8.5 – 11 months of sustained exposure to high, moderate or low irradiance under seasonal environmental conditions. Both symbiotic state and ...


High Prevalence Of The Amphibian Chytrid Fungus (Batrachochytrium Dendrobatidis) Across Multiple Taxa And Localities In The Highlands Of Ethiopia, David J. Gower, Thomas M. Doherty-Bone, Roman K. Aberra, Abebe Mengistu, Silvia Schwaller, Michele Menegon, Rafael O. De Sá, Samy A. Saber, Andrew A. Cunningham, Simon P. Loader Sep 2012

High Prevalence Of The Amphibian Chytrid Fungus (Batrachochytrium Dendrobatidis) Across Multiple Taxa And Localities In The Highlands Of Ethiopia, David J. Gower, Thomas M. Doherty-Bone, Roman K. Aberra, Abebe Mengistu, Silvia Schwaller, Michele Menegon, Rafael O. De Sá, Samy A. Saber, Andrew A. Cunningham, Simon P. Loader

Biology Faculty Publications

Surveys of the potentially lethal amphibian chytrid fungus (Batrachochytrium dendrobatidis - Bd) in Africa are patchy, especially in some regions of high species endemicity. We present results of the first Bd surveys of wild amphibians in Ethiopia, for two upland regions on either side of the Rift Valley: the Bale Mountains and the Kaffa region. Surveys were opportunistic so that robust interpretation of the data is limited. Utilizing diagnostic qPCR assays, 51 out of 120 frogs (14 species in 10 genera) tested positive for Bd at altitudes of 1,620–3,225 m, across all genera and species, and all but ...


Stochastic Population Dynamics In Populations Of Western Terrestrial Garter Snakes With Divergent Life Histories, David A. Miller, William R. Clark, Stevan J. Arnold, Anne M. Bronikowski Aug 2011

Stochastic Population Dynamics In Populations Of Western Terrestrial Garter Snakes With Divergent Life Histories, David A. Miller, William R. Clark, Stevan J. Arnold, Anne M. Bronikowski

Ecology, Evolution and Organismal Biology Publications

Comparative evaluations of population dynamics in species with temporal and spatial variation in life-history traits are rare because they require long-term demographic time series from multiple populations. We present such an analysis using demographic data collected during the interval 1978–1996 for six populations of western terrestrial garter snakes (Thamnophis elegans) from two evolutionarily divergent ecotypes. Three replicate populations from a slow-living ecotype, found in mountain meadows of northeastern California, were characterized by individuals that develop slowly, mature late, reproduce infrequently with small reproductive effort, and live longer than individuals of three populations of a fast-living ecotype found at lakeshore ...


The Interactive Effects Of Predators, Resources, And Disturbance On Freshwater Snail Populations From The Everglades, Clifton B. Ruehl Apr 2010

The Interactive Effects Of Predators, Resources, And Disturbance On Freshwater Snail Populations From The Everglades, Clifton B. Ruehl

FIU Electronic Theses and Dissertations

The origins of population dynamics depend on interplay between abiotic and biotic factors; the relative importance of each changing across space and time. Predation is a central feature of ecological communities that removes individuals (consumption) and alters prey traits (non-consumptive). Resource quality mitigates non-consumptive predator effects by stimulating growth and reproduction. Disturbance resets predator-prey interactions by removing both. I integrate experiments, time-series analysis, and performance trials to examine the relative importance of these on the population dynamics of a snail species by studying a variety of their traits. A review of ninety-three published articles revealed that snail abundance was much ...


Environmental And Endogenous Factors Influencing Emigration In Juvenile Anadromous Alewives, Benjamin I. Gahagan, Eric T. Schultz, Katie E. Gherard Jan 2010

Environmental And Endogenous Factors Influencing Emigration In Juvenile Anadromous Alewives, Benjamin I. Gahagan, Eric T. Schultz, Katie E. Gherard

EEB Articles

We analyzed juvenile anadromous alewife migration at Bride Lake, a coastal lake in Connecticut, during summer 2006 and found that migration on 24-hour and seasonal timescales was influenced by conditions of the environment and characteristics of the individual. To identify environmental cues of juvenile migration, we continuously video recorded fish at the lake outflow and employed information-theoretic model selection to identify the best predictors of daily migration rate. More than 80% of the approximately 320,000 juveniles that migrated from mid-June to mid-August departed in three pulses lasting one or two days. Pulses of migration were associated with precipitation events ...


Predatory Senescence In Ageing Wolves, Daniel R. Macnulty, Douglas W. Smith, John A. Vucetich, L. David Mech, Craig Packer Jan 2009

Predatory Senescence In Ageing Wolves, Daniel R. Macnulty, Douglas W. Smith, John A. Vucetich, L. David Mech, Craig Packer

USGS Northern Prairie Wildlife Research Center

It is well established that ageing handicaps the ability of prey to escape predators, yet surprisingly little is known about how ageing affects the ability of predators to catch prey. Research into long-lived predators has assumed that adults have uniform impacts on prey regardless of age. Here we use longitudinal data from repeated observations of individually-known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park to demonstrate that adult predatory performance declines with age and that an increasing ratio of senescent individuals in the wolf population depresses the rate of prey offtake. Because this ratio fluctuates independently of ...


A Sex Difference In Seasonal Timing Of Birth In A Livebearing Fish, Eric T. Schultz Jan 2008

A Sex Difference In Seasonal Timing Of Birth In A Livebearing Fish, Eric T. Schultz

EEB Articles

Sex differences in seasonal timing include differences in hatch- or birth-date distribution and differences in the timing of migration or maturation such as protandrous arrival timing (PAT), which is early male arrival at breeding sites. I describe a novel form of protandrous arrival timing, as a sex difference in birth-date distribution in a live-bearing fish (Dwarf Perch, Micrometrus minimus). In this species, birth coincides with arrival at breeding sites because newborn males are sexually active. A series of samples of pregnant females and young of year was collected in Tomales Bay, CA. I analyzed the daily age record in otoliths ...


Surviving A Drought: Population Dynamics Of Ochotona Pallasi Pricei In A Dry Steppe, Gobi Altai, Mongolia, Karin Nadrowski, Georg Miehe Jan 2007

Surviving A Drought: Population Dynamics Of Ochotona Pallasi Pricei In A Dry Steppe, Gobi Altai, Mongolia, Karin Nadrowski, Georg Miehe

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

Two distinct life history traits are described from the genus Ochotona, the group of “burrowing” species exhibiting high but fluctuating population densities and the “non-burrowing” species exhibiting relatively stable low population densities. The life history traits are linked to ecosystem dynamics with climatically variable steppe environments hosting “burrowing” species and relatively stable mountainous and rocky habitats hosting “non-burrowing” species. There are few intermediate species, living in both steppe and rocky environments. This study presents survival rates, reproductive rates and a tentative model of population dynamics for Ochotona pallasi pricei, an intermediate species with respect to habitat preference. We used Cormack-Jolly-Seber ...


Time Constraints Mediate Predator-Induced Plasticity In Immune Function, Condition, And Life History, Robby Stoks, Marjan De Block, Stefanie Slos, Wendy Van Doorslaer, Jens Rolff Apr 2006

Time Constraints Mediate Predator-Induced Plasticity In Immune Function, Condition, And Life History, Robby Stoks, Marjan De Block, Stefanie Slos, Wendy Van Doorslaer, Jens Rolff

Open Dartmouth: Peer-reviewed articles by Dartmouth faculty

The simultaneous presence of predators and a limited time for development imposes a conflict: accelerating growth under time constraints comes at the cost of higher predation risk mediated by increased foraging. The few studies that have addressed this trade-off have dealt only with life history traits such as age and size at maturity. Physiological traits have largely been ignored in studies assessing the impact of environmental stressors, and it is largely unknown whether they respond independently of life history traits. Here, we studied the simultaneous effects of time constraints, i.e., as imposed by seasonality, and predation risk on immune ...


Decreased Reproductive Investment Of Female Threespine Stickleback Gasterosteus Aculeatus Infected With The Cestode Schistocephalus Solidus: Parasite Adaptation, Host Adaptation, Or Side Effect?, Eric T. Schultz, Michelle Topper, David C. Heins Jan 2006

Decreased Reproductive Investment Of Female Threespine Stickleback Gasterosteus Aculeatus Infected With The Cestode Schistocephalus Solidus: Parasite Adaptation, Host Adaptation, Or Side Effect?, Eric T. Schultz, Michelle Topper, David C. Heins

EEB Articles

Parasitic infections may cause alterations in host life history, including changes in reproductive investment (absolute amount of energy allocated to reproduction) and reproductive effort (proportion of available energy allocated to reproduction). Such changes in host life history may reflect: 1) a parasite tactic: the parasite adaptively manipulates energy flow within the host so that the host is induced to make a reduction in reproductive effort and reproductive investment, making more energy available to the parasite; 2) no tactic: there is no change in host reproductive effort and reproductive investment simply decreases as a side effect of the parasite depleting host ...


Benthic Fisheries Ecology In A Changing Environment: Unraveling Process To Achieve Prediction, Mark J. Butler Iv Jan 2005

Benthic Fisheries Ecology In A Changing Environment: Unraveling Process To Achieve Prediction, Mark J. Butler Iv

Biological Sciences Faculty Publications

Marine fisheries and the ecosystems that sustain them are increasingly beset by environmental deterioration, and the problem is particularly acute in coastal zones where human Populations are increasing. In the best of circumstances, fishery managers are faced with the multiple, often conflicting, demands of resource users, politicians, and scientists when considering strategies for resource management. A further challenge is that management decisions must be made against a backdrop of a deteriorating environment and the shifting status of coastal ecosystem integrity. Traditional tools for single-species management may be inadequate in these settings. Furthermore. the necessary empirical data to appropriately parameterize models ...


Antipredator Behavior And Physiology Determine Lestes Species Turnover Along The Pond-Permanence Gradient, Robby Stoks, Mark A. Mcpeek Dec 2003

Antipredator Behavior And Physiology Determine Lestes Species Turnover Along The Pond-Permanence Gradient, Robby Stoks, Mark A. Mcpeek

Open Dartmouth: Peer-reviewed articles by Dartmouth faculty

Identifying key traits that shape trade-offs that restrict species to only a subset of environmental gradients is crucial to understanding and predicting species turnover. Previous field experiments have shown that larvae of Lestes damselfly species segregate along the entire gradient of pond permanence and predator presence and that differential predation risk and life history constraints together shape their distribution. Here, we report laboratory experiments that identify key differences in behavior and physiology among species that structure their distributions along this gradient. The absence of adaptive antipredator behavioral responses against large dragonfly larvae and fish of Lestes dryas, the only species ...


The Effects Of Disturbance Architecture On Landscape-Level Population Dynamics, Kirk A. Moloney, Simon A. Levin Mar 1996

The Effects Of Disturbance Architecture On Landscape-Level Population Dynamics, Kirk A. Moloney, Simon A. Levin

Botany Publication and Papers

Phenomena such as disturbance play a major role in structuring ecological systems by producing a spatiotemporal mosaic of patches at different successional states. The distribution of species within the resulting mosaic depends upon an interaction between species' life history traits and the spatial and temporal structure of the ecological processes controlling species' distributions. We have used a spatially explicit simulation model (Jasper) of a serpentine grassland to examine the importance of some of these relationships, focusing primarily on the role of disturbance. The model Jasper is hierarchical in design and was developed to simulate the population dynamics of three interacting ...