Animal Sciences Commons^™

Digging Biomechanics In Geomyoid Rodents, Alexis Moore Crisp

UNLV Theses, Dissertations, Professional Papers, and Capstones

Subterranean digging behaviors provide opportunities for protection, access to prey, and predator avoidance for a diverse array of vertebrates, yet studies of the biomechanics of burrowing have been limited by the technical challenges of measuring kinetics and kinematics of animals moving within a substrate. Prior studies of burrowing have recorded a single axis of x-ray video and/or force. However, empirical observations show that burrowing is not restricted to a single axis or plane. I describe a new system called a ‘tunnel-tube’ for measuring 3D reaction force during burrowing. This tunnel-tube has two separate tubes, one ‘entry tube’ that has no …

Life History Tradeoffs And The Costs Of Reproduction In Arizona Bark Scorpions (Centruroides Sculpturatus), Michael Marie Webber

UNLV Theses, Dissertations, Professional Papers, and Capstones

Tradeoffs in life history evolution result from conflicts in the time and energy that can be simultaneously invested in activities such as growth, reproduction, and survival. Reproduction is an energetically costly activity for organisms, and is known to elicit alterations in the daily activity patterns of individuals. I investigated reproductive tradeoffs in the Arizona Bark Scorpion,Centruroides sculpturatus. To better understand the nature of tradeoffs in this species, I examined the influence of reproductive state on the predatory efficiency and thermal preference of reproductive females. Further, I examined the influence of reproductive activities (i.e. gestation) on the ability of reproductive females …

Effects Of Environmental Variables On The Reproduction Of Quagga Mussels (Dreissena Rostriformis Bugensis) In Lake Mead, Nv/Az, Richard Steven Ianniello

UNLV Theses, Dissertations, Professional Papers, and Capstones

In 2007, quagga mussels (Dreissena rostriformis bugensis) were found in Lake Mead and have spread downstream on the Colorado River and to other lakes and reservoirs in the Southwestern United States. The quagga mussel's extremely quick colonization of Lake Mead and annual veliger abundance trends provide evidence that the quagga mussels in the Southwest have different reproductive behavior than in previous habitats. This study is one of the first to specifically examine quagga mussel reproduction in the Southwest and examines how quagga mussel reproduction varies at sites known to have different temperatures and other environmental variables resulting from the input …

Second-Order Conditioning In Drosophila, Christopher J. Tabone

UNLV Theses, Dissertations, Professional Papers, and Capstones

Animals possess the ability to associate neutral stimuli in their environment with both rewards and punishment. A conditioned stimulus (CS1) such as a smell or sound, can become associated with an unconditioned stimulus (US), such as a food reward, to elicit what is known as the conditioned response (CR). This type of learning is commonly referred to as classical conditioning or first-order conditioning (FOC). Second-order conditioning (SOC) is an extension of this type of association wherein a novel stimulus is introduced (CS2) and associated with a previously conditioning first-order stimulus (CS1). As a result, the organism may show an attraction …

Physiological Implications Of Natural Versus Induced Arousal From Torpor, Jenifer C. Utz

UNLV Theses, Dissertations, Professional Papers, and Capstones

During the hibernation season, animals oscillate between periods of torpor and periods of interbout arousal (IBA). During torpor, body temperature is often near 0° C and metabolism is severely depressed. Oxygen consumption, a proxy for aerobic metabolism, may fall to 1% of active values. Many physiological processes including cardiovascular, respiratory, and cellular functions nearly cease. During the IBA, euthermic body temperature is restored and most systemic and cellular processes function at fully active levels. The transition period between these two physiologically dissimilar states is called arousal.

The rate of rewarming (RRW) during arousal was previously expected to progressively increase until …

From The Valleys To The Mountains: The Biographic History Of Antelope Squirrels, Bats, And Chipmunks In Western North America, Stacy James Mantooth

UNLV Theses, Dissertations, Professional Papers, and Capstones

Genetic differentiation within and between species often coincides with significant geological or climatic changes that have shaped the sizes and locations of their geographic ranges and altered the connectivity between populations over time. Across western North America, many endemic taxa experienced high levels of initial divergence associated with geological transformations of the Neogene, with subsequent diversification and geographic structuring of populations associated with climatic changes during the Quaternary. As such, we can use a combination of molecular markers and genetic analyses to effectively examine the evolutionary and biogeographic histories of populations, species, and regional biotas whose signatures of differentiation are …

Distribution And Site Selection Of Le Conte's And Crissal Thrashers In The Mojave Desert: A Multi-Model Approach, Dawn Marie Fletcher

UNLV Theses, Dissertations, Professional Papers, and Capstones

Information on the distribution and habitat requirements of a species are critical components to the development of meaningful conservation plans. Such knowledge, however, is particularly difficult to obtain for species that are elusive and occur at low densities, such as the Le Conte's ( Toxostoma lecontei ) and Crissal (Toxostoma crissale ) thrashers. In association with a regional conservation plan, I evaluated the distribution and habitat selection of these thrashers within Clark County, Nevada in the eastern Mojave Desert. I used a call-broadcast approach to sample 432 stratified random locations, detecting Le Conte's thrashers at 45 locations and Crissal …