Ecology and Evolutionary Biology Commons^™

Efficacy Of Conservation Actions For Imperiled Colorado River Fishes In The Grand Canyon, Arizona, Brian D. Healy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many fishes are critically imperiled, particularly in their native rivers, due to human water use and dam construction, which can dramatically alter habitats and block fish migratory routes. The introduction of invasive sport-fishes that prey on native fish further threatens native species that maybe restricted to only a single river basin (i.e., “endemic”). To preserve native fishes in river systems with degraded habitats, managers need to understand the effects of conservation actions to ensure limited resources are applied effectively. Two commonly applied native fish conservation actions include removal of invasive fishes, and translocations of native fish from one place into …

Predicting The Impact Of A Northern Pike (Esox Lucius) Invasion On Endangered June Sucker (Chasmistes Liorus) And Sport Fishes In Utah Lake, Ut, Jamie Reynolds

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Invasive species introductions are associated with negative economic and environmental impacts, including reductions in native species populations. Successful invasive species populations often grow rapidly and a new food web structure is established. The ability of invasive species to outcompete and prey upon native species are two characteristics that make them a leading cause of fish extinctions in North America.

Northern pike (Esox lucius; hereafter pike) are voracious ambush top predators \native to the upper Midwest and Mid-Atlantic regions of the lower 48 United States, Alaska, and southern Canada. Pike have been spreading across the Intermountain West and Pacific …

Diet, Density, And Distribution Of The Introduced Greenhouse Frog, Eleutherodactylus Planirostris, On The Island Of Hawaii, Christina A. Olson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The greenhouse frog, Eleutherodactylus planirostris, native to Cuba and the Bahamas, was recently introduced to Hawaii. Studies from other invaded habitats suggest that it may impact Hawaiian ecosystems by consuming and potentially reducing endemic invertebrates. However, there have been no studies on the greenhouse frog in Hawaii. The first component of this study was to conduct a diet analysis. We conducted a stomach content analysis of 427 frogs from 10 study sites on the island of Hawaii. At each site, we also collected invertebrates using two different sampling methods: leaf litter collection and sticky traps to characterize available resources. …

Reproductive Tactics Of Aphidophagous Lady Beetles: Comparison Of A Native Species And An Invasive Species That Is Displacing It, Yukie Kajita

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Coccinella septempunctata L. (Coleoptera: Coccinellidae) has been introduced to North America in recent decades, raising concerns of adverse impacts on native lady beetles, including the congeneric C. transversoguttata richardsoni (Brown). The central focus of my dissertation is to understand the importance of reproduction, in particular, in promoting invasion of C. septempunctata and its replacement of native lady beetles in alfalfa fields of western North America.

Studies were conducted to compare reproductive tactics of the invasive C. septempunctata and the native C. transversoguttata, by addressing: 1) maximum rate of reproduction of overwintered lady beetles, 2) population dynamics of the invasive …