Browsing by Subject "Bird"

Now showing 1 - 4 of 4
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    Assessing bat and bird fatality risk at wind farm sites using acoustic detectors
    (2014-08) Heist, Kevin W.
    Wind power is a promising and rapidly growing clean energy technology. Despite its environmentally friendly reputation, industrial wind energy generation can have serious impacts on wildlife. Bat and bird collision fatality rates have been alarmingly high at some wind farms. Proper siting of wind facilities may help minimize collision impacts; however, there is no reliable method for assessing risks prior to development. My goal was to develop a method for predicting fatality rates at prospective wind energy sites by monitoring acoustic activity of bats and birds. I monitored bat and bird activity using ultrasonic-acoustic detectors at 160 locations, in a variety of landscape settings to: 1) examine the utility of the detectors for monitoring bat and bird activity for pre-construction site assessment, 2) evaluate the ability of an automated bat call identification program to identify the species of recorded calls, 3) determine how pass rates relate to fatality rates, 4) examine how pass rates vary with respect to specific landscape features, 5) examine how activity differs before versus after a wind facility is built, and 6) investigate whether bat activity levels are elevated near turbines. Ground-based recording was found to be useful for studying near-ground bat activity patterns at multiple scales, but patterns of bird activity were apparent only at the coarsest geographic scale. The bat call identification program produced mixed results among species and regions. No relations between bat pass rates and fatality rates among wind farms were found. Large differences in bat and bird activity among geographic regions were found, with highest levels near Great Lakes coastlines. Also, bat and bird activity was elevated near edges of forested river corridors, relative to distances farther from the edge. Distance to water, distance to trees, and ecoregion were found to be good predictors of bat activity levels. Models of bird activity were of limited usefulness in explaining spatial variation in pass rates. Ground-based acoustic recorders were not found to be a good predictor of bat fatalities; however, they did reveal local and regional patterns that may be useful for siting wind energy facilities in low-impact areas.
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    The effect of urbanization on the stopover ecology of neotropical migrant songbirds
    (2015-04) Condon, Elisabeth Lee
    I conducted spring migration point counts and vegetation surveys at 29 forest patches in the Chicago, IL metropolitan area in 2012 and 2013. The forest patch selection was designed to test the effects of patch size, distance from the Lake Michigan shoreline and degree of urbanization. I conducted exploratory analysis to search for potential relationships. Vegetation structure variables, especially understory and subcanopy composition, were important factors for many models. Bird species determined to be area sensitive in previous studies were associated with large patches during migration. While path size, distance from the shoreline and urbanization were not frequently selected for models of the entire avian community, they were important in most models of individual species. No single combination benefitted all species, indicating that maintaining a variety of conditions in the region will support a diverse avifauna.
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    Habitat and landscape associations of breeding birds in forested peatlands, Minnesota, USA.
    (2017-05) Bednar, Joshua
    I compared breeding bird habitat use and community metrics among ten lowland conifer cover types in northern Minnesota. Breeding birds were sampled at 130 points distributed throughout black spruce, tamarack and white cedar forests within the Agassiz Lowland Subsection (ALS), Minnesota. Birds were sampled three times in the spring and summer of 2013 and twice during the spring and summer of 2014. I identified ten lowland conifer cover types using hierarchical clustering then identified distinctive breeding bird species of the ten lowland conifer cover types through indicator species analyses-percent perfect indication (PPI). Connecticut Warbler (Oporornis agilis) was most distinctive in semi-productive black spruce-tamarack bog cover types (PPI=40, P<0.01). Boreal Chickadee (Poecile hudsonicus) was most distinctive in productive black-spruce-tamarack bog cover types (PPI=8, p<0.01). Species such as the Nashville Warbler (Leiothlypis ruficapilla), Yellow-rumped Warbler (Setophaga coronata) and White-throated Sparrow (Zonotrichia albicollis) were ubiquitous across many lowland conifer cover types. The cluster analysis identified two bird communities that responded to differences in vegetation at the landscape level. Results from the Canonical Correspondence Analysis (CCA) showed significant relationships between breeding birds and vegetation variables (p<0.01). The results from the CCA ordination support the ten cover types identified from the hierarchical cluster analysis. These findings can inform forest and wildlife management decisions that will benefit the conservation and management of breeding birds in lowland conifer forests of the ALS. Disturbances such as logging, insect outbreaks, fire and climate change have the capacity to significantly alter bird communities within these lowland coniferous forests. Data presented here can improve our predictions of how the ALS avifauna will change given future changes to lowland conifer forests in the ALS.
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    Phylogeography of palearctic birds using mulyilocus coalescence analyses
    (2012-07) Hung, Chih-Ming
    The phylogeography of three widespread Palearctic passerines were characterized in this dissertation based on sequence data from mitochondrial and nuclear genes, which were analyzed under a framework of the coalescence. The following questions were addressed: (1) does gene history reflect species history, (2) does natural selection on mitochondrial DNA (mtDNA) obscure phylogeographic inference, and (3) do the early stages of speciation reveal ecological niche divergence. In chapter one, phylogeographic histories based on mtDNA and 13 nuclear genes of Eurasian nuthatches (Sitta europaea) were compared to address an ongoing debate over the value of mtDNA in phylogeography. Both mtDNA and multilocus nuclear data recovered the same three clades. The results suggested that mtDNA is efficient in discovering phylogeographic pattern due to its fast coalescence rate; whereas, multiple (nuclear) genes are required to quantify process parameters such as effective population size, gene flow and divergence time. In chapter two, I devised novel methods based on coalescent simulations to discover whether natural selection has influenced the mitochondrial genome of two Old World flycatcher species (Ficedula parva and F. albicilla). The simulations were based on the estimated demographic history using 18 nuclear genes, which suggested that the two sister species diverged around three million years ago and that F. albicilla, but not F. parva, experienced a recent population expansion. My analyses showed that population bottlenecks alone could not fully explain the strikingly low variation in the mtDNA data, and I concluded that the mtDNA patterns were affected by natural selection. Thus, interpreting the phylogeographic history based solely on mtDNA can be misleading. Chapter three involved coalescence and simulation approaches based on mtDNA and a Z-linked gene to explore the early stages of evolutionary divergence in the common rosefinch (Carpodacus erythrinus). The third chapter also involved an assessment of ecological niche divergence and the results showed no evidence of ecological divergence at the early stages of diversification among three rosefinch lineages. This dissertation demonstrates that the incorporation of multiple genes, coalescence theory, and analytic approaches from other fields (e.g., ecological niche modeling) can provide fresh insights into phylogeographic history of species.