Matching Items (13)

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Riparian Forest Restoration: Conflicting Goals, Trade-Offs, and Measures of Success

Description

Restoration projects can have varying goals, depending on the specific focus, rationale, and aims for restoration. When restoration projects use project-specific goals to define activities and gauge success without considering

Restoration projects can have varying goals, depending on the specific focus, rationale, and aims for restoration. When restoration projects use project-specific goals to define activities and gauge success without considering broader ecological context, determination of project implications and success can be confounding. We used case studies from the Middle Rio Grande (MRG), southwest USA, to demonstrate how restoration outcomes can rank inconsistently when narrowly-based goals are used. Resource managers have chosen MRG for restoration due to impacts to the natural flood regime, reduced native tree recruitment, and establishment of non-native plants. We show restoration “success” ranks differently based upon three goals: increasing biodiversity, increasing specific ecosystem functions, or restoring native communities. We monitored 12 restored and control sites for seven years. Treatments ranked higher in reducing exotic woody populations, and increasing proportions of native plants and groundwater salvage, but generally worse at removing fuels, and increasing species and habitat structural diversity. Managers cannot rely on the term “restoration” to sufficiently describe a project’s aim. Specific desired outcomes must be defined and monitored. Long-term planning should include flexibility to incorporate provisions for adaptive management to refine treatments to avoid unintended ecological consequences.

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Created

Date Created
  • 2012-09-19

Warrior Cats and Ecology

Description

My thesis/creative project is a series of videos, supplemented by a paper documenting all the research. The project focuses on domestic and feral cats through the viewpoint of the “warrior

My thesis/creative project is a series of videos, supplemented by a paper documenting all the research. The project focuses on domestic and feral cats through the viewpoint of the “warrior cats” book series. The use of a particular fandom as a vehicle for science communication is a unique platform for use as a thesis/creative project. The narrated videos are made with the intention of being presented on YouTube or a similar viewing platform to an audience that is already familiar with the book series. The videos would fit on the site as a form of educational film known as video essays. The videos cover a range of topics to relate this book series to real situations with domestic animals, particularly cats, and wildlife. Each video is around ten to twenty minutes long and presented as episodes in a series.
The objective of my thesis project is to help bridge the gap between entertainment and science. I grew up reading the warrior cats, and I assume I was similar to many other children and young teens who did not understand domestic cats or ecology enough to question anything in the books. I know that much of these books are fictional, but that does not mean that it can’t be analyzed and used as a tool for teaching. The goal is to reach common ground with those people who have an interest in the warrior cats series, and help them understand it in a new light, as well as the world around them. I aim for the takeaway of this series to encourage people to explore the concepts I discuss and consider expanding upon the ideas within the Warriors universe or with their own cats.

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Created

Date Created
  • 2020-05

Urbanization alters herbivore rodent composition but not abundance

Description

Desert ecosystems are one of the fastest urbanizing areas on the planet. This rapid shift has the potential to alter the abundances and species richness of herbivore and plant communities.

Desert ecosystems are one of the fastest urbanizing areas on the planet. This rapid shift has the potential to alter the abundances and species richness of herbivore and plant communities. Herbivores, for example, are expected to be more abundant in urban desert remnant parks located within cities due to anthropogenic activities that concentrate food resources and reduce native predator populations. Despite this assumption, previous research conducted around Phoenix has shown that top-down herbivory led to equally reduced plant biomass. It is unclear if this insignificant difference in herbivory at rural and urban sites is due to unaltered desert herbivore populations or altered activity levels that counteract abundance differences. Vertebrate herbivore populations were surveyed at four sites inside and four sites outside of the core of Phoenix during fall 2014 and spring 2015 in order to determine whether abundances and richness differ significantly between urban and rural sites. In order to survey species composition and abundance at these sites, 100 Sherman traps and 8 larger wire traps that are designed to attract and capture small vertebrates such as mice, rats, and squirrels, were set at each site for two consecutive trap nights. Results suggest that the commonly assumed effect of urbanization on herbivore abundances does not apply to small rodent herbivore populations in a desert city, as overall small rodent abundances were statistically similar regardless of location. Though a significant difference was not found for species richness, a significant difference between small rodent genera richness at these sites was observed.

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Created

Date Created
  • 2016-05

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The Effect of Arthropod Biomass on Lizard Abundance

Description

The effects of biocontrol and the potential risks associated with them are of interest to many researchers. In the Virgin River area of Nevada, natural resource managers have done studies

The effects of biocontrol and the potential risks associated with them are of interest to many researchers. In the Virgin River area of Nevada, natural resource managers have done studies of various removal techniques on the non-native Tamarix spp. strands. One such area of focus is the use of biocontrol in the form of the tamarisk leaf beetle (Diorhabda spp.), and the resulting changes in the environment from the defoliation of the trees. Previous studies have shown that removal of the plants can potentially be beneficial to lizards. But do changes in the environment change the amount of food available? We were interested to see if the amount of arthropod biomass from these areas had a relationship with the lizard abundance. Taking arthropod collection data from the Virgin River, we compared it with arthropod data over several years, before and after Diorhabda was introduced in 2010. Arthropod biomass data was obtained by taking the collected arthropods and drying them in an oven and weighing them. Results show that there is no correlation between the arthropod numbers or biomass with the amount of lizards in the area, that biomass was greatest after biocontrol introduction, and biomass was highest in mixed Tamarix and native tree strands versus just Tamarix strands. In conclusion, arthropod numbers and biomass have shown to be a poor indicator of lizard abundance, and factors such as temperature changes in the environment might be a better indicator of the changing abundance of lizards.

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Created

Date Created
  • 2014-05

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Environmental Perceptions: An Analysis of Snake Populations Surrounding Phoenix Neighborhoods and Resident Survey Responses

Description

Urban encroachment into traditional snake territories has long been underway; likely increasing snake sightings in urban neighborhoods. With increasing overlap, I ask if the perceptions of snakes are actually influencing

Urban encroachment into traditional snake territories has long been underway; likely increasing snake sightings in urban neighborhoods. With increasing overlap, I ask if the perceptions of snakes are actually influencing urban residents to say that snakes are a significant problem in their neighborhood today? I was interested in finding out whether or not there would be a positive correlation between the perception of snakes being a problem within a neighborhood and the actual number of sightings recorded. To address this, I used survey responses from 2017 regarding the risk perception of snakes from twelve neighborhoods within Maricopa County. These responses were then compared to the number of snake sightings within those same neighborhoods over a span of ten years using community science data from iNaturalist. The average results of the people who took the survey perceived that snakes were not a problem in their neighborhood. It was also found that in the outlying areas closer to natural snake habitat (desert preserves), a positive correlation between a higher survey response and a higher number of snake sightings could be seen. Overall, the conclusion of the data revealed that the perceptions of residents did not align with the actual number of snake sightings.

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Created

Date Created
  • 2021-05

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Wildlife Strikes at Airports: What are the Contributing Factors?

Description

In the U.S., less than 20 percent of wildlife strikes are reported, which leaves a large portion of incidents unaccounted for. Although wildlife strikes at airports often go unreported, since

In the U.S., less than 20 percent of wildlife strikes are reported, which leaves a large portion of incidents unaccounted for. Although wildlife strikes at airports often go unreported, since the early 1990's the number of wildlife strikes has increased five-fold and the number of damaging strikes has increased 1.5-fold. Goals for this project include determining if biological and landscape variables are good predictors of wildlife strikes. We define response variables as the number of reported wildlife strikes per 10,000 airport operations. We studied seven major airports around Phoenix, Arizona and 30 large airports in the western U.S. In the Phoenix metro valley, airports varied from having 0.3 strikes per year per 10,000 operations to having 14.5 strikes from 2009 to 2013. We determined bird richness by using the citizen-science database "eBird,"and measured species richness within a 15 kilometer area of each airport. Species richness between hotspots ranged from 131 to 320. Seasonal differences were determined using an analysis of variance (ANOVA) analysis for the seven Phoenix metro airports as well as the 30 western U.S. airports. Our results showed that there was a seasonal difference in wildlife strikes in the majority of our airports. We also used land use data from CAP LTER to determine any environmental factors such as vicinity to water or fence line located within five kilometers from airports using ArcGIS. These results are important because they are helpful in determining the factors influencing wildlife strikes based on the number of strikes reported.

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Created

Date Created
  • 2015-05

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The effects of artificial water sources on small mammal communities

Description

Modified and artificial water sources can be used as a management tool for game and non-game wildlife species. State, federal, and private agencies allocate significant resources to install and maintain

Modified and artificial water sources can be used as a management tool for game and non-game wildlife species. State, federal, and private agencies allocate significant resources to install and maintain artificial water sources (AWS) annually. Capture mark recapture methods were used to sample small mammal communities in the vicinity of five AWS and five paired control sites (treatments) in the surrounding Sonoran desert from October 2011 to May 2012. I measured plant species richness, density, and percent cover in the spring of 2012. A Multi-response Permutation Procedure was used to identify differences in small mammal community abundance, biomass, and species richness by season and treatment. I used Principle Component Analysis to reduce 11 habitat characteristics to five habitat factors. I related rodent occurrence to habitat characteristics using multiple and logistic regression. A total of 370 individual mammals representing three genera and eight species of rodents were captured across 4800 trap nights. Desert pocket mouse (Chaetodipus penicillatus) was the most common species in both seasons and treatments. Whereas rodent community abundance, biomass, and richness were similar between seasons, community variables of AWS were greater than CS. Rodent diversity was similar between treatments. Desert pocket mouse abundance and biomass were twice as high at AWS when compared to controls. Biomass of white-throated woodrat (Neotoma albigula) was five times greater at AWS. Habitat characteristics were similar between treatments. Neither presence of water nor distance to water explained substantial habitat variation. Occurrence of rodent species was associated with habitat characteristics. Desert rodent communities are adapted for arid environments (i.e. Heteromyids) and are not dependent on "free water". Higher abundances of desert pocket mouse at AWS were most likely related to increased disturbance and debris and not the presence of water. The results of this study and previous studies suggest that more investigation is needed and that short term studies may not be able to detect interactions (if any) between AWS and desert small mammal communities.

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Agent

Created

Date Created
  • 2013

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Statistical evaluation and GIS model development to predict and classify habitat quality for the endangered southwestern willow flycatcher

Description

The Southwestern Willow Flycatcher (Empidonax traillii extimus) has been studied for over two decades and listed as endangered for most of that time. Though the flycatcher has been granted protected

The Southwestern Willow Flycatcher (Empidonax traillii extimus) has been studied for over two decades and listed as endangered for most of that time. Though the flycatcher has been granted protected status since 1995, critical habitat designation for the flycatcher has not shared the same history. Critical habitat designation is essential for achieving the long-term goals defined in the flycatcher recovery plan where emphasis is on both the protection of this species and "the habitats supporting these flycatchers [that] must be protected from threats and loss" (U.S. Fish and Wildlife Service 2002). I used a long-term data set of habitat characteristics collected at three study areas along the Lower Colorado River to develop a method for quantifying habitat quality for flycatcher. The data set contained flycatcher nest observations (use) and habitat availability (random location) from 2003-2010 that I statistically analyzed for flycatcher selection preferences. Using both Pearson's Chi-square test and SPSS Principal Component Analysis (PCA) I determined that flycatchers were selecting 30 habitat traits significantly different among an initial list of 127 habitat characteristics. Using PCA, I calculated a weighted value of influence for each significant trait per study area and used those values to develop a habitat classification system to build predictive models for flycatcher habitat quality. I used ArcGIS® Model Builder to develop three habitat suitability models for each of the habitat types occurring in western riparian systems, native, mixed exotic and exotic dominated that are frequented by breeding flycatchers. I designed a fourth model, Topock Marsh, to test model accuracy on habitat quality for flycatchers using reserved accuracy assessment points of previous nest locations. The results of the fourth model accurately predicted a decline in habitat at Topock Marsh that was confirmed by SWCA survey reports released in 2011 and 2012 documenting a significant decline in flycatcher productivity in the Topock Marsh study area.

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Agent

Created

Date Created
  • 2013

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Response of waterbird communities to habitat and landscape structure along an urban gradient in Phoenix, Arizona

Description

Urban riparian corridors have the capacity to maintain high levels of abundance and biodiversity. Additionally, urban rivers also offer environmental amenities and can be catalysts for social and economic revitalization

Urban riparian corridors have the capacity to maintain high levels of abundance and biodiversity. Additionally, urban rivers also offer environmental amenities and can be catalysts for social and economic revitalization in human communities. Despite its importance for both humans and wildlife, blue space in cities used by waterbirds has received relatively little focus in urban bird studies. My principal objective was to determine how urbanization and water availability affect waterbird biodiversity in an arid city. I surveyed 36 transects stratified across a gradient of urbanization and water availability along the Salt River, a LTER long-term study system located in Phoenix, Arizona. Water physiognomy (shape and size) was the largest factor in shaping the bird community. Connectivity was an important element for waterbird diversity, but not abundance. Urbanization had guild-specific effects on abundance but was not important for waterbird diversity. Habitat-level environmental characteristics were more important than land use on waterbird abundance, as well as diversity. Diving and fish-eating birds were positively associated with large open bodies of water, whereas dabbling ducks, wading birds, and marsh species favored areas with large amounts of shoreline and emergent vegetation. My study supports that Phoenix blue space offers an important subsidy to migrating waterbird communities; while alternative habitat is not a replacement, it is important to consider as part of the larger conservation picture as traditional wetlands decline. Additionally, arid cities have the potential to support high levels of waterbird biodiversity, heterogeneous land use matrix can be advantageous in supporting regional diversity, and waterbirds are tolerant of urbanization if proper resources are provided via the habitat. The implications of this study are particularly relevant to urban planning in arid cities; Phoenix alone contains over 1,400 bodies of water, offering the opportunity to design and improve urban blue space to optimize potential habitat while providing public amenities.

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Agent

Created

Date Created
  • 2016

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Personality in the City: Relationship Between Animal Behavioral Traits And Urbanization in a Fragile, Human-impacted Desert Ecosystem

Description

Human-inhabited or -disturbed areas pose many unique challenges for wildlife, including increased human exposure, novel challenges, such as finding food or nesting sites in novel structures, anthropogenic noises, and novel

Human-inhabited or -disturbed areas pose many unique challenges for wildlife, including increased human exposure, novel challenges, such as finding food or nesting sites in novel structures, anthropogenic noises, and novel predators. Animals inhabiting these environments must adapt to such changes by learning to exploit new resources and avoid danger. To my knowledge no study has comprehensively assessed behavioral reactions of urban and rural populations to numerous novel environmental stimuli. I tested behavioral responses of urban, suburban, and rural house finches (Haemorhous mexicanus) to novel stimuli (e.g. objects, noises, food), to presentation of a native predator model (Accipiter striatus) and a human, and to two problem-solving challenges (escaping confinement and food-finding). Although I found few population-level differences in behavioral responses to novel objects, environment, and food, I found compelling differences in how finches from different sites responded to novel noise. When played a novel sound (whale call or ship horn), urban and suburban house finches approached their food source more quickly and spent more time on it than rural birds, and urban and suburban birds were more active during the whale-noise presentation. In addition, while there were no differences in response to the native predator, rural birds showed higher levels of stress behaviors when presented with a human. When I replicated this study in juveniles, I found that exposure to humans during development more accurately predicted behavioral differences than capture site. Finally, I found that urban birds were better at solving an escape problem, whereas rural birds were better at solving a food-finding challenge. These results indicate that not all anthropogenic changes affect animal populations equally and that determining the aversive natural-history conditions and challenges of taxa may help urban ecologists better understand the direction and degree to which animals respond to human-induced rapid environmental alterations.

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Agent

Created

Date Created
  • 2018