Thesis (Ph. D.)--University of Wisconsin, 1966. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

The breeding ecology and the behaviour of the Glaucous-winged Gull (Larus glaucesens) were studied at Mandarte Island, British Columbia, Canada, in the summers of I96I and 1962. Data were obtained on pair-bondage, pair formation, philopatry to nest site, egg-laying, clutch-size, incubation, egg and chick mortality, fledging rate, growth, age at first flight and colony departure, annual adult mortality and longevity. No support was found for: 1. The Fraser Darling Effect that there is a greater synchronisation of breeding at greater densities; 2. Lack's hypothesis that the clutch size of each species of bird has been adapted by natural selection to correspond with the largest number of young for which the parents can, on the average, provide enough food. In the Glaucous-winged Gull the converse of these theories was established for the year. / Science, Faculty of / Zoology, Department of / Graduate

Thesis (M.Sc.)--Memorial University of Newfoundland, 2003. / Includes bibliographical references. Also available online.

Thesis (Ph.D.)--Memorial University of Newfoundland, 2003. / Includes bibliographical references.

Thesis (Ph.D.)--Murdoch University, 2004. / Thesis submitted to the Division of Science and Engineering. Bibliography: leaves 298-317.

No description available.

Guillemots have been studied on the Isle of May since 1980. Between 184 and 581 individually identifiable birds were ringed as chicks each year since 1983. Cumulative known survival rates varied from 14-39% for cohorts at least 3 years of age. Survival rate was highly significantly negatively correlated with the number of hours of gale force winds in the three months after a cohort first goes to sea. Immatures did not return to the colony until at least 2 years of age. The proportion of a cohort attending the colony increased, cohorts arrived at the colony earlier in the season, and individuals were seen more often up to the age of 4-5. Experienced individuals arrived earlier, were seen more often, and were more likely to recruit than inexperienced birds of the same age. Two and 3 years olds but very few older birds visited sea rocks below the colony; all ages were seen on top ledges and on sites within the breeding colony. Immatures tended to visit the same subcolony repeatedly; older cohorts were more sedentary. Guillemots were highly philopatric to their natal subcolonies as prebreeders and recruits. Recruitment age varied from 3 years to 8+, median 6. Recruits fledged 0.26 chicks/pair compared to 0.79/pair in the breeding population as a whole. Recruits arrived earlier in the year of recruitment, and in the previous year, than same-aged birds which did not recruit. Substantial numbers of immatures from other colonies visited the Isle of May and Isle of May bred birds were observed elsewhere. Non-native immatures were seen fewer times than natives. Activity at the colony varied little between immature cohorts, but suggested increasing competitive ability with age. The results are discussed in relation to wider issues in seabird behaviour and ecology.

A survey in 1994 recorded nearly 14,000 pairs of Larus gulls of four species nesting on buildings in Britain and Ireland. The majority of these records involved Herring Gulls, although large numbers of Lesser Black-backed Gulls were also observed. Since the last such survey in 1976, Lesser Black-backed Gulls had shown the highest rate of increase. Despite the sharp decline in the numbers of Herring Gulls breeding in Britain and Ireland since the mid-1970s, numbers nesting on roofs had continued increasing, albeit at a lower rate than before. New developments since 1976 included increasing numbers nesting inland and on the roofs of large industrial buildings. The study of a colony of Herring Gulls and Lesser Black-backed Gulls nesting on one such industrial building showed that the breeding success of these birds, although lower than that found for roof-nesting birds at more dispersed colonies, was higher than that at many traditional colonies. Low nest density, shelter for chicks and safety from predators were thought to be important contributors to this success. In addition, die colony was situated very close to the sources of food, agricultural land and urban areas, found to be most important in die diet of Herring Gulls nesting there. A review of dietary studies of roof-nesting Herring Gulls found that, despite the location of such colonies in urban areas, urban sites were not always an important source of food. The reduction in availability of one urban source of food, untreated sewage, was found to have little effect upon the gulls using an urban stretch of river. In particular, neither of the species causing most problems in urban areas, the Herring Gull and Lesser Black- backed Gull, decreased in number; in fact, numbers of these species nesting on buildings in the area increased considerably.

Thesis (M. Sc.), Memorial University of Newfoundland, 1999. / Restricted until June 2000. Bibliography: p. 39-42.

No description available.