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The Effects Of Habitat Isolation On Fine-Scale Genetic And Geographic Structure Of Populations Of Two Threatened Endemic Insects In Southern Nevada, Pseudocotalpa Giulianii And Icaricia Shasta Charlestonensis, Kristen Tovar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Assessing the role geographic isolation and ecological specialization have on phylogeographic patterns contributes to our understanding of the evolutionary history of a species and the processes that erode genetic diversity. I used mitochondrial and nuclear genomic sequences to assess whether habitat isolation has shaped the fine-scale patterns of present-day genetic structure and diversity in two threatened insect species endemic to southern Nevada. Pseudocotalpa giulianii (Coleoptera; Scarabaeidae) is a dune obligate scarab beetle endemic to only two small, isolated sand dunes in Nye County, Nevada, with a usable habitat of less than 4.2 km sq that is impacted by on-going degradation. …

A Comparison Of Population Sizes And Number Of Captures For The Desert Woodrat (Neotoma Lepida) In Two Microhabitats In The Las Vegas Wash, Nevada, Jayson Barangan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Planned removal and eradication of saltcedar in the Las Vegas Wash, Nevada could potentially generate adverse impacts on present desert woodrat (Neotoma lepida) populations inhabiting the area. Consequently, research was conducted investigating population sizes of N. lepida in two distinct microhabitat types, saltcedar (Tamarix sp.) and mesquite/quailbush (Prosopis sp./Atriplex lentiformis). The results of this study will aid in gauging the effects of the changes in vegetation once restoration work is completed and assist with logistical scheduling for implementation of control measures. Mark-recapture field techniques were utilized for data collection from July 2002 to June 2003. Population estimates were calculated using …

The Effects Of Off-Road Vehicle Use In Desert Tortoise (Gopherus Agassizii) Habitats, Brent D. Clark

UNLV Theses, Dissertations, Professional Papers, and Capstones

The desert tortoise (Gopherus agassizii) populations have been in decline and have been placed on the endangered species list. No single factor is ultimately responsible for the tortoise decline. It is a combination of events that collectively have a negative impact. I chose to focus my study on only one factor, off-road vehicles. By evaluating the damage done to the terrain by off-road vehicles, a better understanding of their impact on the tortoise populations can be assessed and protective measures taken.

The amount of available vegetation does not seem to play a role in their decisions of which plants to …