We determined foraging characteristics of Cerulean Warblers (Dendroica cerulea) in Morgan-Monroe and Yellowwood state forests in southern Indiana from 2007-2009. The average foraging height, tree height, and tree diameter at breast height (dbh) were greater for males than females. During 2008, areas of our study site received silvicultural manipulations that allowed us to compare foraging behavior before and after treatments. Harvesting techniques included shelterwood and clearcut or single and group tree selection. Foraging Cerulean Warblers in harvested areas had a lower average foraging height, tree height, and dbh during post-treatment than in pre-treatment years. Additionally, we examined foraging tree species selection and determined expected foraging tree species use based on basal area and stem density of tree species in the territories. We compared territory composition to random sites to explore tree selection on a larger scale. The most commonly used foraging tree species were bitternut hickory (Carya cordiformis), white oak (Quercus alba), and tulip tree (Liriodendron tulipifera). / Department of Biology

Thesis (M.S.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on November 1, 2007) Includes bibliographical references.

Thesis (Ph. D.)--North Carolina State University, 2005. / Title from PDF t.p. (viewed on Jan. 25, 2006). Includes vita. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains vi, 53 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 28-35).

This study presents the results of a field study comparing the effects of two forest harvest methods on the Cerulean Warbler, a state-endangered songbird. Population estimates and a breeding study produced no significant differences among groups, although the species was not attracted to forest openings and experienced decreased nest success in treated sites. Additional study on prey influences showed strong correlations with timing of breeding and peak larval lepidopteran abundance, specifically on oak and hickory tree species. Data suggests that these trees are vital to increased probability of nest success due to an increase in prey availability within territories. Further study is recommended to ascertain the long-term effects of forest harvest and the importance of oak and hickory dominated landscapes to the persistence of this species. / Cerulean warbler population response and nesting success in forests with recent silviculture -- Avian nesting ecology and prey abundance using frass drop as an indicator. / Department of Biology

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains vii, 89 p. : ill. Includes abstract. Includes bibliographical references.

Over the past five decades, populations of the Cerulean Warbler (Setophaga cerulea) have declined precipitously and the response of populations to silviculture has been identified as a high-priority research need. This species was studied in nine forest management units in Southern Indiana following a harvest that took place in 2008. Males were detected, territories were demarcated, and male age-class was determined to identify settlement patterns. Vegetation was measured in all territories and associated random non-use sites. Data analyzed in ArcMap (ArcGIS 10) show that Cerulean Warbler territory size was smallest and density was highest in even-aged units. Territories contained a greater number of small woody species than non-use sites but no vegetative differences existed between male age-classes. Instead, males appeared to select areas by relying on social cues from experienced neighbors. It is possible that “social attraction” management techniques could influence male Cerulean Warbler settlement patterns, providing a valuable tool for the conservation of this species. / Forest management effects on cerulean warbler territory size in southern Indiana -- Conspecific social cues strongly influence cerulean warbler male settlement patterns in a managed forest. / Department of Biology

Recent advances in the analysis of intrinsic markers, particularly stable isotopes, have allowed great insight into interactions between different stages of the annual cycle of migratory birds. Hydrogen isotope ratios, because of strong latitudinal trends in their distribution, have been widely used to address long-distance movements of migratory birds. Likewise, carbon isotope ratios have been useful in examinations of habitat quality because of their responsiveness to changes in plant community composition. However, basic assumptions underlying the use of certain isotopes have yet to be adequately examined. Additionally, much of the research regarding seasonal interactions in migratory songbirds comes from study of a single species, and it is unclear whether these findings are applicable to a wider range of migrant songbirds. In this study, I collected tissue samples from black-throated blue warblers (Dendroica caerulescens) at a breeding site in New Hampshire to address two important questions regarding stable isotopes and the investigation of seasonal interactions. First, using feather samples from both adult and juvenile birds, I investigated the influence of age, molt timing, and reproductive effort in determining the stable hydrogen isotope ratios that are incorporated into tissue samples. Secondly, I took claw samples from adult birds to examine the importance of winter habitat quality, as inferred through carbon isotope ratios, in determining subsequent reproductive success. I found that hydrogen isotope ratios in feather samples were significantly influenced by both age and molt timing, though not by reproductive effort. The mechanism underlying age-related isotopic variation is unclear, but may be widespread among passerines. In addition, this study is the first to note a significant seasonal trend in feathers grown throughout a breeding season, although the mechanism for this pattern is also unclear. Taken together, these findings have important implications for the use of hydrogen isotope ratios for purposes of geographic assignment. Further research is needed to determine the prevalence and magnitude of age-related and seasonal trends in hydrogen isotope ratios. I recommend that future studies note the age class of birds when sampling for hydrogen isotopes, and researchers should attempt to collect feathers grown early in the molt cycle. Analysis of carbon isotope ratios from claw samples indicated that winter habitat quality did not directly influence subsequent reproductive success. However, winter habitat quality may have an indirect influence on reproductive output. Females from higher quality wintering sites were in significantly better body condition on the breeding grounds, and settled on more insect-rich breeding territories. Both body condition on the breeding grounds and breeding territory quality have previously been shown to influence subsequent reproductive success, in this and other songbird species. These results indicate that winter habitat quality may be important in determining future reproductive success for black-throated blue warblers, and interactions between events during the wintering and breeding periods may need to be incorporated into future population models for this species.

Flamboyant plumage and ornamentation is common and well-known in male birds; it serves as a sexual display to attract potential mates. While flamboyant plumage is less common and usually more subtle in female birds, it does occur in some species such as Dark-Eyed Juncos (Junco hyemalis) and Prothonotary Warblers (Protonotaria citrea). Prothonotary Warblers display relatively subtle sexual dimorphism. This study examines variations in tail spot patterns in Prothonotary Warblers and relates those variations to age in females. Females with fewer than six spots tend to be two years old or younger; females with six spots or more tend to be three years old or older. The tail spot numbers of mated pairs were also analyzed. Statistical analyses indicate that males mate with females with six tail spots more often than they mate with females with other numbers of tail spots. This suggests males prefer females who are at least three years old.

A controversy dating from the appearance of Altum's book, Der Vogel und sein Leben, 1868 (Mayr, 1935) is that of the biological function or functions of the territorial behavior in birds. However, attention was not focused upon this problem until the advent of Howard's book, Territory in Bird Life, published in 1920. In a general review of the problem Hinde (1956) discussed several functions of the territory and presented evidence both for and against their importance. The more important of these presumed functions are; (1) limitation of population density; (2) facilitation of pair formation and maintenance of the pair bond; (3) reduction in interference with reproductive activities by other members of the species; (4) provision of an adequate food supply for rearing the young; (5) reduction of loss to predators; (6) reduction of time spent in aggression; and (7) prevention of epidemics.