Abstract not available

Thesis (D. Min.)--Erskine Theological Seminary, 1999. / Abstract. Includes bibliographical references (leaves 249-252).

Thesis (D. Min.)--Erskine Theological Seminary, 1999. / Abstract. Includes bibliographical references (leaves 249-252).

Thesis (D. Min.)--Erskine Theological Seminary, 1999. / Abstract. Includes bibliographical references (leaves 249-252).

Presentations of three potential nest intruders were used to investigate house wren nest defense behavior, while regular nest box checks provided information regarding house wren nest-destroying behavior. During nest defense trials, male wrens were typically more active in defense than females in the egg stage but no intersexual differences existed in the nestling stage. Males' greater defensiveness could be an extension of their territory defense role. Defense vocalizations were sex biased, with males giving primarily song calls and females giving chatter calls. Both sexes maintained or lowered their defense levels from egg to nestling stage, possibly due to decreased offspring vulnerability. House wrens altered their defense behaviors among intruder species, depending on the type of threat. Males exhibited greater defense levels against the house wren model compared to the bluebird or cowbird model in the egg stage but showed no differences among model species in the nestling stage. Females exhibited no defense differences among model species. Male defense levels were affected by their breeding strategy, as attentive males were more aggressive toward the house wren and cowbird models than non-attentive males. Attentive males discriminated among intruder species while non-attentive males did not. Lack of male attentiveness, due to polygamy or attempted polygamy, appeared to be potentially costly to females, regardless of their order of pairing with the male. House wren nest destroying behavior (NDB) varied with respect to the timing of house wren nest attacks, the abandonment and reacquisition of nests following a wren attack, and the status of neighboring house wren nests at the time of a nest attack. Some supportive evidence was found for the existing NDB hypotheses, but no single hypothesis was completely supported. House wren NDB may serve several functions but may ultimately depend on house wren population density. / Department of Educational Leadership

Thesis (Ph. D.)--University of Chicago, Faculty of the Division of the Biological Sciences and the Pritzker School of Medicine, Department of Ecology and Evolution, June 2001. / Includes bibliographical references. Also available on the Internet.

This work provides an initial characterization of song sharing among males in the Northern House Wren (Troglodytes aedon parkmanii). A sample of 21 different males was studied at two different locations across two breeding seasons in southern Alberta, Canada. In total, 35,067 songs were analyzed to assess patterns of song sharing among males within and between study sites and in returning males between years. Virtually all syllable types (n=27) were shared among males. However, they were used to create very large repertoires of mostly unique song types. Absolute levels of song sharing among males was low but song sharing was higher among neighbouring males and decreased with increasing distance between males and across study sites. These patterns are discussed as they relate to important issues in the process of song learning, in the functions of large song repertoires in mate attraction and territory defense, and in the potential formation of dialects in this species. / xi, 102 leaves ; 29 cm

The objectives of the study were to determine the year-round distribution and habitat selection of four marsh passerine species, as described by vegetation type and its physical characteristics, and to investigate interspecific competition as a factor in the habitat selection of the Long-billed Marsh Wren and the Red-winged Blackbird. Fulfillment of these objectives should help the B.C. Fish and Wildlife Branch to assess the effects of their management plans on marsh passerines. I determined the abundance of four passerine species in different vegetation types via marsh census transects over the period of one year. Nesting habitat and breeding information on marsh wrens and redwings was obtained via nest study plots. The results were: Areas traversed from the central and deepest marsh outward towards higher ground are inhabited by redwings, marsh wrens. Common Yellowthroats, and Song Sparrows, respectively. Habitats of wrens and redwings are spatially and temporally segregated. Wrens use the "Dense Spiraea" (Hardhack shrub) habitat extensively, while redwings use it hardly at all in the marsh. Similarly, redwings are abundant in Scirpus cyperinus (Hairy-seeded Bulrush), whereas wrens seldom use this habitat. Both wrens and redwings use other vegetation types, but redwings use them in the late spring, whereas wrens use them in the summer. Both wrens and redwings have lower reproductive success when nesting in close proximity than when nesting apart. This supports the hypothesis that interspecific competition exists and indicates that selection may favour habitat segregation. I also found mutual suppression of reproductive success when the effects of different vegetation types were removed. The results were not statistically significant however, possibly due to small sample sizes. Of the observed differences between the physical nest site parameters of wrens and redwings, vegetation height and presence and/or depth of water require further investigation as factors in the habitat selection of the two species. Bren-wren competition does not appear to affect wren nesting success in the present study marsh. Management recommendations are given based on the objective of maintaining and possibly enhancing bird species diversity in the study marsh. / Science, Faculty of / Zoology, Department of / Graduate