The Effects of Urban Edge Proximity on Mesopredator Populations Adjacent to Gold Canyon, Az

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Description
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

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.
Date Created
2016-05
Agent

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

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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 in human communities. Despite its importance for both humans and

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.
Date Created
2016
Agent