Urban landscapes are complex social-ecological systems comprising human and natural elements and their interactions. A key priority for research in these landscapes is understanding how humans affect the presence and abundance of wild organisms and how those organisms, in turn, provide ecosystem services that affect humans. In this dissertation, I use two field studies to understand the ecosystem services provided by urban animals in green spaces across Philadelphia and in a third study I investigate geographic bias in where urban animals have been studied in the United States. For the first study, I use a functional trait approach to examine how urban bird communities respond to landscape- and local-scale habitat and how community composition corresponds to potential ecosystem services. I show that the landscape-scale context of a green space has a stronger influence on species’ abundances than local-scale habitat. As a result, the effect traits associated with cultural and regulating ecosystem services varied strongly along the landscape-scale gradient of urbanization. Local-scale variation in habitat had little effect. The importance of landscape-scale habitat in driving the supply of bird-mediated ecosystem services underscores the importance of regional urban planning for green spaces.In the second study, I use a field experiment to determine the drivers of an understudied ecosystem service – the removal of littered food waste by birds and squirrels. I recorded food removal activity by animals in green spaces across Philadelphia and found that Eastern gray squirrels (Sciurus carolinensis) are the main driver of this service. With increased squirrel abundance, removal level is higher and is both initiated and completed more quickly. This service is also context dependent, such that more food is removed in urban parks and picnic areas, where animals are presumably accustomed to consuming anthropogenic foods. These results highlight the importance of animal behavior, and factors that affect it, for the supply of ecosystem services. In my third study, I take a geographic approach to identifying bias in the study of animals in urban landscapes. Our knowledge of urban ecosystems in the United States is based on hundreds of field studies and thousands of individual field sites, but the distribution of these sites has never been examined. I reviewed the literature and mapped field sites to assess geographic bias in the location of urban ecology field sites. At a national scale, I find that urban ecologists tend to work in larger cities, especially those that are less socioeconomically vulnerable (more affluent). I also find that the social-ecological attributes of the neighborhoods in which ecologists work depends on the framing of their study as well as the focal taxa and functional groups studied. Overall, the neighborhoods where marginalized people live are an underexplored segment of the urban landscape. This is the first study to identify geographic biases in urban ecology field sites and provides a basis for future urban ecology research that produces knowledge applicable to all cities and neighborhoods. / Biology

Biases in invasion science lead to a taxonomic focus on plants, particularly a subset of well-studied plants, and a geographic focus on invasions in Europe and North America. Geographic biases could also cause some branches of invasion science to focus on a subset of environmental conditions in the invaded range, potentially leading to an incomplete understanding of the ecology and management of plant invasions. While broader, country-level geographic biases are well known, it is unclear whether these biases extend to a finer scale and thus affect research within the invaded range. This study assessed whether research sites for ten well-studied invasive plants in the U.S. are geographically biased relative to each species’ invaded range. We compared the distribution, climate, and land uses of research sites for 735 scientific articles to manager records from EDDMapS and iMap Invasives representing the invaded range. We attributed each study to one of five types: impact, invasive trait, mapping, management, and recipient community traits. While the number of research sites was much smaller than the number of manager records, they generally encompassed similar geographies. However, research sites tended to skew towards species’ warm range margins, indicating that researchers have knowledge on how these plants might behave in a warming climate. For all but one species, at least one study type encompassed a significantly different climate space from manager records, suggesting that some level of climatic bias is common. Impact and management studies occurred within the same climate space for all species, suggesting that these studies focus on similar areas – likely those with the greatest impacts and management needs. Manager records were more likely to be found near roads, which are both habitats and vectors for invasive plants, and on public land. Research sites were more likely to be found near a college or university. Studies on these plants largely occur across their invaded range, however, different study types occur within a narrower climate range. This clustering can create gaps in our general understanding of how these plants interact with different environments, which can have important policy and management consequences.