Ecology and Evolutionary Biology Commons^™

How Beavers (Castor Canadensis) Affect Habitat Availability For Two Native Oregon Turtles: Actinemys Marmorata And Chrysemys Picta Bellii, Rodé Krige

University Honors Theses

Oregon is home to two native freshwater turtle species: the northwestern pond turtle and the western painted turtle. Both turtles are Oregon conservation strategy species with a status rating of sensitive, indicating declining populations. Oregon’s decline in these turtle’s populations is thought to be predominantly due to loss and degradation of habitat that results from development and urbanization. Beavers’ ability to dam streams and create ponds may be creating habitat usable by turtles, but the relationship is under-studied. This study assessed water temperature, basking habitat, and overall turtle habitat suitability at beaver-dammed and control ponds in Portland, Oregon. Average basking …

Assessment Of Factors Influencing Migratory Landbird Use Of Forested Stopover Sites Along The Delmarva Peninsula During Autumn Migration, J. Andrew Arnold

Biological Sciences Theses & Dissertations

Autumn migration is a time when billions of birds move from breeding grounds in North America to wintering grounds in Central and South America, with many individuals relying on stopover habitats en route for resting and refueling purposes. These stopover sites are critical to the survival of the hundreds of species of migratory landbirds that migrate annually, and thus identifying important stopover sites is a high priority for conserving such taxa. The Delmarva Peninsula; a coastal region of Delaware, Maryland, and Virginia along the mid-Atlantic flyway; consists of forested habitats with ample food and shelter that likely serves as quality …

Habitat Selection And Host Detection In The Salamander Mussel, Simpsonaias Ambigua, Eric A. Stegmann

MSU Graduate Theses

The native freshwater mussels, Order Unionida, have suffered many species extinctions and loss of abundance. Two important threats to native mussels are loss of habitat and loss of access to the vertebrate hosts of the parasitic mussel larvae. The Salamander mussel, Simpsonaias ambigua, is a habitat specialist, living under flat rocks. It is often found in direct association with its only known host, the common mudpuppy, Necturus maculosus. This association could result from movement and habitat selection by the mussels themselves. Alternatively, it might result from the deposition of juveniles by a resident host. Habitat selection and host …

Multivariate Habitat-Based Predictive Modeling Of Three Demersal Rockfish Species In Central California, Georgia R. Martel

Cal Poly Humboldt theses and projects

Accurate, spatially explicit models of rockfish abundance are critical in implementing ecosystem-based management strategies and designating essential fish habitats and marine protected areas. Multibeam bathymetry methods and visual, non-extractive submersible transect surveys were combined to collect environmental variables and fish abundance data at three distinct sites within the study region. Zero-adjusted models were developed using habitat classification analyses of high-resolution (5 m) digital elevation models. Model accuracies were assessed by using a reserved subset of the original datasets. To demonstrate that a model’s predictive power was linked to its spatial origins, Mean Absolute Error and coefficient of determination values were …

Use And Partitioning Of Riparian Corridors By Mammalian Carnivores In Rio Mora National Wildlife Refuge, Armando Toral Becker

Regis University Student Publications (comprehensive collection)

Land conversion across the Southwestern U.S. for agricultural and livestock use and prolonged drought conditions cascade to reduce ecosystem function, including habitat provision for wildlife. Arroyo restoration efforts aim to improve wildlife habitat by decreasing soil erosion and enhancing water retention. These hydrologic and geomorphic changes increase the likelihood that wildlife use restored corridors by increasing riparian vegetation cover. Rio Mora National Wildlife Refuge (RMNWR) has restored several arroyos by installing a system of one-rock dams throughout the refuge, but the extent to which mammals prefer restored over unrestored riparian corridors and how habitat structure influences mammalian use and density …

Autumn Roost Selection By Male Hoary Bats (Lasiurus Cinereus) In Northern California, Danielle (Skye) Salganek

Cal Poly Humboldt theses and projects

The hoary bat, Lasiurus cinereus, is a solitary bat that roosts in the foliage of trees throughout the western hemisphere. Roosts are subject to the ambient temperature of their surroundings, thus hoary bats undergo long-distance migrations between summer and winter ranges to avoid freezing temperatures. Habitat selection has been studied during the summer for maternal female hoary bats, but not during migration and winter. Autumn migration coincides with the hoary bat mating period and it has been proposed that male and female bats may rendezvous on migration paths. Individuals may select roosts in stopover locations that enhance fitness by providing …

Where Birds Chill: An Assessment Of The Habitat Preferences Of Birds Overwintering In Hudson Valley Forests, Elizabeth Claire Axley

Senior Projects Spring 2019

Many avian species overwinter in eastern North America; however, studies on bird populations are rarely undertaken during this critical survival time, and little is known as to their habitat preferences and foraging behavior. In this observational study, we performed a survey of birds overwintering in the Hudson Valley’s temperate, primarily-deciduous forests, assessing avian populations’ habitat preferences through the vegetative structural variables surrounding overwintering birds as they forage. Our results suggest that high canopy cover is critically important to predicting overwintering bird occupancy on a microhabitat scale. Moreover, overwintering birds preferentially occupy forest plots not dominated by sugar maples, in spite …

Population Health Of Spotted Salamanders (Ambystoma Maculatum) In Created Vernal Pools: An Integrative Approach, Alice R. Millikin

Graduate Theses, Dissertations, and Problem Reports

Habitat creation is an important tool for conservation to counteract habitat loss and degradation. Vernal pools are susceptible to destruction due to limited detection, protection, and regulation. These wetlands provide fishless breeding habitat for many amphibian species including spotted salamanders (Ambystoma maculatum) in eastern North America. Determining whether created vernal pool habitat is successful is often determined by demographic data of colonizing populations. I suggest that hormone levels, population genetics, and disease prevalence can improve our understanding of population health in created habitat. The goal of this dissertation was to assess the health of spotted salamander larvae in …

Assessment And Mapping Of The Milwaukee Estuary Habitat, Brennan Dow

Theses and Dissertations

Rivermouth regions such as the Milwaukee Harbor, are the habitat interface between watersheds and the Great Lakes proper, and can host a large diversity of fishes. To facilitate an ecosystem approach management strategy, I developed a layered map that includes bathymetry, side scan sonar images, shoreline substrate classifications, and initial data of aquatic vegetation and centrarchid spawning locations. The 60 km perimeter of the study area consisted of 59% hardened shoreline. Ground truthing of substrate classifications via Ponar grabs or video had about 95% accuracy for fine and rocky boulder substrates. Rocky fine was the most inaccurate classification (35%), but …

Habitat Useage Of Tri-Colored Bats (Perimyotis Subflavus) In Western Kentucky And Tennessee Post-White Nose Syndrome, Katherine Schaefer

Murray State Theses and Dissertations

The tri-colored bat (Perimyotis subflavus) has declined severely across its range since 2006 due to white nose syndrome, a fungal disease causing massive bat mortality in North America. My objective was to determine distinguishing characteristics of roost trees and habitat used by tri-colored bats so that the species’ needs can be considered in management plans. I mist-netted for tri-colored bats in western Kentucky and Tennessee during the summers of 2015 and 2016, and attached a radio transmitter to each captured adult bat. I tracked 15 bats to their day roosts and collected habitat data at 38 roost areas …

Habitat Use And Movement Patterns Of Two Redwood Forest Salamanders, Aneides Vagrans And Ensatina Eschscholtzii, With An Examination Of The Efficacy Of Pit Tags For Marking Small Plethodontids, Christian Brown

Cal Poly Humboldt theses and projects

The habitat use and movements of small, secretive salamanders are generally poorly understood, in part due to the difficulty associated with marking and recapturing such animals. This study was designed to test the efficacy, both in the laboratory and in the field, of using passive integrated transponder (PIT) tags to mark and track two small-bodied plethodontid salamander species native to coastal northwestern California, Aneides vagrans, the Wandering Salamander, and Ensatina eschscholtzii, the Ensatina Salamander.

Aneides vagrans inhabits tree crowns. Using cover objects and visual encounter surveys, I searched for A. vagrans in the angiosperm understory canopy at least twice …

An Investigation Of Juvenile Alewife (Alosa Pseudoharengus) Habitat Use And Growth Using Natural Markers, Gregory Norman Labonte Ms

All Student Scholarship

This research attempts to connect patterns in growth and migration of an anadromous species. The goal of this research was to understand habitat movements and growth of juvenile alewives (Alosa pseudoharengus) in the Penobscot Estuary and Bay through the use of otolith microchemistry, otolith growth increments, and a laboratory stable isotope turnover study. Understanding the connection between growth and movement of juvenile alewives may lead to more accurate and sophisticated conservation and restoration methods for anadromous species.

Variation In Habitat Thresholds: An Analysis Of Minimum Habitat Requirements Of North American Breeding Birds, Yntze Van Der Hoek

Dissertations, Theses, and Capstone Projects

Many species show dramatic changes in population extinction or persistence probability at particular habitat amounts. These `extinction thresholds' could be translated to conservation targets, under the condition that we can derive generalities. I investigated the level of variation in landscape-level habitat thresholds for a suite of North American, forest-associated, breeding birds. Records from Breeding Bird Atlases and the availability of remotely-sensed land cover data allowed me to compare habitat thresholds for 25 species across the states of Massachusetts, Michigan, New York, Ohio, Pennsylvania, and Vermont. I show that variation in thresholds is considerable (Chapter II, III), as thresholds range from …

Ecology Of The Rock Rattlesnake, Crotalus Lepidus, In The Northern Chihuahuan Desert, Vicente Mata Silva

Open Access Theses & Dissertations

The Rock Rattlesnake, Crotalus lepidus is a small species that is found from southern Arizona, southern New Mexico, and southern Texas, in the U.S., into northern Mexico. To date, little is known about the ecology of this species. Ecological information is becoming desperately needed for supporting the conservation and protection of species living in fragile environments such as the Chihuahuan Desert amid current local and global threats (e.g., habitat destruction and modification, urban development, and climate change). Although rattlesnakes spend a significant amount of time underground while overwintering, little is known about the physiology and behavior of these organisms during …