The introduction of livestock to the vast majority of public lands may be used to simulate the conditions provided by herbivorous grazers in the past, however little data has been collected on the effects of livestock grazing in Sonoran desert habitats. Vegetative species that are characteristic of the Arizona Upland subdivision of the Sonoran desert did not evolve with extensive grazing by large ungulate populations, and therefore the response to livestock grazing is of particular interest. Four historic Parker 3-step clusters in south-central Arizona were sampled in three cohorts between 1953 and 2016 to interpret changes in rangeland health using soil coverage data, species richness and frequency, and long-term photo point comparisons. Cattle grazing was active across the allotment until 1984, allowing approximately 30 years of rest before the third and final cohort was measured. Over the entirety of this study, there was a 66.67% increase in perennial basal hits, a 56.29% increase in rock, and a 44.55% increase of forage basal hits. Decreases were seen in litter (-57.69%) and bare soil hits (-8.76%). Cluster 3 consistently had a lower percent of cover across all classes of vegetation in the 2014 cohort

(-81.61%), however the average percent of cover increased by 63.16% (40 hits) across the allotment. Available species richness data from 1971 and 2014 cohorts indicates a 112% increase in unique species; however, species richness increases in the 2014 cohort are largely based on recruitment of non-palatable species (71%). Although the status of some species were undetermined, all individuals identified to species in the invader class (non-palatable) were determined to be native to the study site. Perennial grass frequency became less abundant over the duration of this study, while growth was predominantly observed in shrubs. Increases in species frequency was detected on two of the four clusters measured in the 2014 cohort; the growth was primarily observed in jojoba (Simmondsia chinensis), oak (Quercus spp.), and catclaw acacia (Senegalia greggii) in C4, and hopseed bush (Dodonaea viscosa) in C2.

Urbanization is a landscape-level alteration of habitat that can lead to habitat fragmentation, degradation, and the introduction of nonnative species. Due to their life history characteristics, mammalian predators are particularly vulnerable to these effects. The categorization of many species as synanthropic, benefiting from human development, has been difficult as species have a gradient of responses to urbanization. Although coyotes, gray foxes and bobcats have all been shown to benefit from light to moderate levels of urbanization, often due to the increase in food resources, they typically require access to natural areas as escape cover. Camera traps at varying distances were used to document mesopredator response to the urban edge of Gold Canyon, Arizona from November 2015 through March 2016. Coyote, gray fox and bobcat relative abundance did not vary with distance to urban edge during this time period. Although, negative trends suggest that a larger scale study may reveal a negative relationship between distance to urban edge and mesopredator abundance for all 3 of these species. The efficacy of different baits at increasing mesopredator detections was also tested, with insignificant results. However, coyotes seemed to be more likely to interact with Carman's Raccoon Lure No. 2 than coyote urine. Understanding the responses of mesopredators to urbanization will allow us to better coexist with these vulnerable species as land continues to be developed at high rates across the globe.

Populations of resident Canada geese (Branta canadensis) that nest and reside within the contiguous United States have increased at a rate of 7.9% per year to over 3.5 million over the last few decades. Enlarged population levels have resulted in conflicts between geese and humans, including property damage and human health and safety concerns. Noticeable growth of the population of Canada geese in the Indian Bend Wash area of Scottsdale, AZ has been observed in recent years sparking concern that this population will continue to grow at high rates as seen in other urban areas throughout North America. This study was initiated to determine the current population structure, distribution, and productivity of this population of resident geese. During the 2009 to 2010 post-breeding molt, 255 geese were captured and affixed with neck collars allowing individual identification. I conducted surveys from October 2008 to September 2010 and calculated weekly population estimates from mark recapture survey data using the Lincoln-Peterson method. Productivity was also investigated. Nesting was largely limited to one island within the study area, suggesting geese preferentially nest in insular areas to avoid human disturbance. Despite limited nesting opportunities, there was a significant population increase of 15 to 25% from 2009 to 2010 based on population estimates. Goose movement patterns indicate this population has a high level of site fidelity to nesting and molting areas, as has been found in other studies of resident Canada geese. I suggest that management should be implemented to 1) reduce the current population of resident geese through adult removal and 2) limit future recruitment into the population through control of reproduction and habitat modification.