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Full-Text Articles in Life Sciences

Timing Is Everything: Climate Change Implications For Phenological Events And Reproductive Success In River Herring, Meghna N. Marjadi Aug 2023

Timing Is Everything: Climate Change Implications For Phenological Events And Reproductive Success In River Herring, Meghna N. Marjadi

Doctoral Dissertations

Anadromous river herring (alewife (Alosa pseudoharengus) and blueback herring (Alosa aestivalis)) make annual spring spawning migrations from the ocean to freshwater, where juveniles reside before emigrating to the ocean. Climate change may alter environmental and biological cues that prompt both adult migration and juvenile emigration, with implications for adult spawning success and offspring survival for these imperiled species. Shifts in adult migration have been observed in some rivers, while impacts on reproductive success and juvenile survival remain unknown. Cues for juvenile emigration are poorly understood as they have been explored at limited spatial and temporal scales. …


Beyond The Fat: Protein Metabolism And Muscle Function As Part Of The Migratory Syndrome Of Songbirds, Cory R. Elowe Apr 2023

Beyond The Fat: Protein Metabolism And Muscle Function As Part Of The Migratory Syndrome Of Songbirds, Cory R. Elowe

Doctoral Dissertations

Migration allows animals to seasonally exploit favorable habitats that are geographically disparate, and migratory animals have a suite of adaptations to complete their extraordinary journeys. This “migratory syndrome” of traits is comprised of seasonally-responsive adaptations that together result in changes to metabolism, body composition, and reproductive status, all of which act to increase the probability of a successful migration. The focus of my dissertation is to investigate the suite of changes in metabolism and muscle function that enable birds to undertake long-duration flights. In chapter 1, I compare fuel use in flight between two related migratory warbler species that migrate …


Drivers And Direct Impacts Of Lean Mass Dynamics On The Stopover Ecology And Migratory Pace Of Nearctic-Neotropical Migrant Songbirds In Spring, Mariamar Gutierrez Ramirez Mar 2022

Drivers And Direct Impacts Of Lean Mass Dynamics On The Stopover Ecology And Migratory Pace Of Nearctic-Neotropical Migrant Songbirds In Spring, Mariamar Gutierrez Ramirez

Doctoral Dissertations

Annual migration in songbirds is one of the most demanding life-history stages. It represents a period of high mortality, yet there is still much unknown about the ecological correlates that influence its successful completion. After long non-stop migratory flights, birds require a stopover period to rest and replenish depleted energy reserves. Birds use fat as the primary fuel to power long-distance flights. However, birds also burn lean tissue, which results in significant reductions in muscle and organ masses. The discovery and quantification of lean mass catabolism represented a paradigm shift in migration ecology because non-fat components were thought to remain …


Don't Delay: The Effects Of Tide Gates And Road-Stream Crossing Culverts On River Herring (Alosa Spp.) Spawning Migrations, Derrick J. Alcott Dec 2020

Don't Delay: The Effects Of Tide Gates And Road-Stream Crossing Culverts On River Herring (Alosa Spp.) Spawning Migrations, Derrick J. Alcott

Doctoral Dissertations

River herring (Alosa spp.) are anadromous fish that spawn in freshwater rivers and lakes in North America from Florida to Nova Scotia, CA. They have been listed as a species of conservation concern due to dramatic stock declines observed in the 1970’s. Stocks have failed to show significant signs of recovery despite over a decade of harvest restrictions throughout their range. Bycatch in commercial fisheries and reduced access to spawning habitat due to anthropogenic barriers to migration, such as dams and tide gates, have been identified as major causes of the decline in herring populations. Physical barriers to …


Not Gone With The Wind: Addressing Effects Of Offshore Wind Development On Bat Species In The Northeastern United States, Zara Rae Dowling Nov 2018

Not Gone With The Wind: Addressing Effects Of Offshore Wind Development On Bat Species In The Northeastern United States, Zara Rae Dowling

Doctoral Dissertations

Development of coastal and offshore wind energy resources has the potential to add considerable renewable electricity capacity to the United States electrical grid, but could have detrimental impacts on wildlife. Land-based wind energy facilities are estimated to kill hundreds of thousands of bats every year in the United States, and could threaten population viability of some species. Little is known about the potential impacts of offshore wind development on bat populations along the North Atlantic coast, but a number of species are known to frequent marine islands or fly over the ocean during migration. This dissertation helps to characterize risks …


Cadherin-11 Ectodomain Signaling In Cranial Neural Crest Migration, Ketan Mathavan Mar 2018

Cadherin-11 Ectodomain Signaling In Cranial Neural Crest Migration, Ketan Mathavan

Doctoral Dissertations

During development, a multi-potent group of cells known as the cranial neural crest (CNC) migrate to form craniofacial structures. Proper migration of these cells requires proteolysis of cell adhesion molecules, such as cadherins. In Xenopus laevis, preventing extracellular cleavage of cadherin-11 impairs CNC migration. However, overexpression of the soluble cleavage product (EC1-3) is capable of rescuing this phenotype. The mechanism by which EC1-3 promotes CNC migration has not been investigated until now. Here we show that EC1-3 stimulates phosphorylation of Akt, a target of PI3K, in X.laevis CNC. Through immunoprecipitation experiments, we determined that EC1-3 interacts with …


Tracking Migratory Bird Movements In The Gulf Of Maine With Automated Radio Telemetry And Stable Hydrogen Isotope Markers, Jennifer Smetzer Mar 2018

Tracking Migratory Bird Movements In The Gulf Of Maine With Automated Radio Telemetry And Stable Hydrogen Isotope Markers, Jennifer Smetzer

Doctoral Dissertations

Coastal and offshore areas of the eastern United States provide valuable resources for both migratory songbirds and breeding seabirds, but face some of the most drastic rates of habitat alteration and urbanization. Coastal development can result in loss of significant habitats, and in proliferation of collision hazards that can pose a grave threat to birds. Conserving birds that use these coastal and offshore areas requires better information on how coastal stopover habitats are used, what breeding populations visit these regions during migration, how birds move through these landscapes, and how development can be most sensibly and responsibly directed to minimize …


Modelling Bird Migration With Motus Data And Bayesian State-Space Models, Justin Baldwin Oct 2017

Modelling Bird Migration With Motus Data And Bayesian State-Space Models, Justin Baldwin

Masters Theses

Bird migration is a poorly-known yet important phenomenon, as understanding movement patterns of birds can inform conservation strategies and public health policy for animal-borne diseases. Recent advances in wildlife tracking technology, in particular the Motus system, have allowed researchers to track even small flying birds and insects with radio transmitters that weigh fractions of a gram. This system relies on a community-based distributed sensor network that detects tagged animals as they move through the detection nodes on journeys that range from small local movements to intercontinental migrations. The quantity of data generated by the Motus system is unprecedented, is on …


Movements And Conservation Of The Migratory White-Eared Kob (Kobus Kob Leucotis) In South Sudan, Malik D. Marjan Nov 2014

Movements And Conservation Of The Migratory White-Eared Kob (Kobus Kob Leucotis) In South Sudan, Malik D. Marjan

Doctoral Dissertations

The annual movements of white-eared kob (Kobus kob leucotis), tiang (Damaliscus korrigum tiang), in eastern South Sudan was investigated to provided appropriate information for developing effective conservation actions for the migratory kob. Although kob is the focus of the study tiang has been included as the two migrations are ecologically linked and overlap at least in the wet season. During the 20 years of the civil war which ravaged South Sudan, the kob and tiang populations were thought to be severely hunted for food by both the combatants and local people to the extent that their …


Birdsong Variation As A Source Of Information For Migrating Common Yellowthroats, Rachel Theresa Bolus Sep 2013

Birdsong Variation As A Source Of Information For Migrating Common Yellowthroats, Rachel Theresa Bolus

Open Access Dissertations

Social information affects the movement decisions of animals and is often an essential factor in habitat selection. Social information should be especially relevant to long-distance migrating birds that navigate over long distances through unfamiliar habitats to find resources to survive. This information likely varies in both availability and importance at the different spatial scales relevant to migrating birds. Using the common yellowthroat as a case study, I tested whether cues might be available in the songs of locally breeding birds at the continental, within-site, and within-territory scales. At the continental scale, I described the geographic variation in song among genetic …