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Kittiwakes have been studied in detail at North Shields, Tyne and Wear, England since 1954. I investigated die effect of mate change (due to divorce or mate death) on reproductive performance. Below average productivity in the year of divorce and in the preceding year, coupled with a low adult survival rate in the year following divorce, suggested birds which divorced were poorer quality individuals than birds which retained their mate. Productivity was reduced if one or both members of a pair were in their last year of life and was indicative of a decline m fitness. Dispersal, breeding and the importance of nest site tenacity to mate retention were studied when kittiwakes were prevented from returning to their original nest sites in 1991. In 1991, extensive non-breeding (57%) and low productivity resulted. Of die birds which bred, 54 (83%) nested in the immediate colony area and only 11 moved to other colonies. Despite moving site, many birds retained their mate of the previous breeding season. In the following year, a further 61 kittiwakes moved and nested at other colonies and about a third retained theu" mate. This, and other evidence, suggests that individual recognition is important in mate retention. Reproductive performance, in relation to nest position in the colony and proxunity to other nesting pairs, was compared with a kittiwake colony at Marsden, NE England. Productivity was highest at the centre of the colonies and, at the edge, was highest for pairs which nested adjacent to another pair. It is suggested that social stimulation, arising from nesting adjacent to another pair, advanced the date of laying. Adult attendance at the nest during chick-rearing was monitored at Marsden in three years. During comparable time periods ui 1991 and 1993,93% and 75% of die broods, respectively, were attended by an adult, compared to only 51% during the same period in 1992. Attendance decreased in relation to hatching date, chick age and brood size and increased with parental age and/or quality.

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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

This thesis is a journey that unfolds alongside the transformations of a river during springtime. Moods and movements captured by Ted Hughes in his poem Stump Pool in April inspire a series of explorations that set out to express the affective vectors of the river???s becoming through sculpture and architecture. The thesis is a manifestation of this search. Arranged as a narrative in five chapters, each offers an account of the emergence of the five works. The first three are a sculptural response to each stanza of the poem: Prometheus manifests the river???s phase-shift from ice to water, Sky Burial from water to steam and Icarus the passage of steam rising towards the sun. Prometheus??? torment, the tearing dispersal of the body during a funerary ritual and the ecstatic flight of Icarus are caught through three material and fire based experiments. Chapter four reflects on these works while investigating the conception and construction of the Bruder Klaus Chapel by the renowned Swiss architect Peter Zumthor. The fifth chapter moves the exploration from sculpture to architectural design deploying the lessons learned from the previous works. Forces of descent rather than ascent now inform the creation of a torrential void, A Lover???s Enclosure. The trajectory in each work and through the series is guided by what feels right, by the unpredictability of the material imagination, working by hand, and by forming and re-forming reoccurring themes as they reverberate and transform in a continuum of affective transformations.

Grassland bird species have declined dramatically since 1966. This decline can be linked to changes in land use practices, such as grazing. I examined the effects of cattle grazing on the abundance of birds by testing the predictions of the More Individuals Hypothesis (MIH). The study was conducted in Grasslands National Park of Canada (GNPC) in Saskatchewan. Point counts were used to sample richness and relative abundance of birds. I sampled two groups of invertebrates: grasshoppers and carabid beetles. In addition, vegetation measurements were taken to assess the intensity of grazing. I found that (1) grasshopper abundance, richness and diversity were higher in grazed pastures; (2) carabids showed mixed responses to grazing; (3) bird abundance was correlated with carabid abundance, thus supporting the assumptions of the MIH. Overall, my results indicate that grazing can be beneficial for both birds and their invertebrate prey in southern Saskatchewan mixed-grass prairies.

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