Thesis

Assessment of the state of information needed for conservation of birds in the Birds of North America

Often the first step in petitioning for a species to be listed under the Endangered Species Act (ESA), or for evaluating management alternatives, is to conduct a population viability analysis (PVA). A PVA is a case-by-case risk analysis used to assess the probability of extinction in the future (Schaffer 1990). PVAs use data on demographic rates, and assumptions about population processes, as well as assumptions about threat conditions and their effects on demography (Doak, et al., 2015). A PVA can indicate the urgency of instituting recovery efforts, identify which demographic rates are particularly important for persistence, and provide information needed to determine eligibility for listing of a species under the ESA. This project assesses whether information needed to run a PVA for species of conservation concern can be found in the Birds of North America (BNA), which is a comprehensive set of species accounts written by recognized experts, for all breeding birds in North America. The BNA was used to document whether data on demographic characteristics, ecological characteristics, and anthropogenic threats were available for each 721 bird species. Because consistent patterns of missing information can help direct research efforts, possible explanations for knowledge gaps of information needed to run a PVA were researched; body mass, ecoregion occupancy, conservation status listing, and taxonomic order were explored as the potential drivers of knowledge gaps. Species mass did not prove to be a significant driving factor; however, limited data were available for analysis. Conservation status listing was not a significant driving factor, data indicated no consistent tendency for listed species to have more or less information known about them. Overall results show that the ecoregions a species occupies (p=0.005) and the taxonomic Order it belongs to (p=0.005) are the best predictors of knowledge gaps for species of breeding birds of North America. Taxonomic Order indicated that anthropogenic threats are either all well known together or all unknown together for bird Orders observed. Additional research is needed to identify why these patterns exist and how to fill the gaps in knowledge. Surprisingly, across all species there was no information about the anthropogenic threats evaluated 42% of the time. Anthropogenic threat studies will become increasingly important as bird populations fluctuate and human impacts on the environment continue to increase.

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