The breeding bird assemblages of blanket bog and moorland habitats in the United Kingdom are of special international importance. They are characterised by species drawn from arctic to temperate regions breeding at high density and showing a particular affinity for open, in parts waterlogged, grazed and burned landscapes. Much recent debate has focussed on the effects of conifer plantations on the distribution and breeding success of these birds. This study concentrates on differences in breeding distribution and success of selected moorland birds. On blanket bog in Caithness and on heather moorland in Grampian Region, moorland waders <i>Charadrii</i> and red grouse <i>Lagopus lagopus scoticus</i> were counted using three methods cross-checked against each other; a) transects using trained dogs, b) listening for calls at dawn and dusk, and c) daylight transects without dogs. Counts were done on afforested ground and adjacent 'edge' areas, and on open moorland far from trees. In Caithness, densities of moorland waders on afforested ground started to decline as soon as planting began, and none was found inside plantations > 7 years old. Red grouse densities on afforested ground in Caithness and in Grampian rose higher than on open moorland areas during the first five years after planting, before declining. It is suggested that red grouse will disappear from afforested ground in Caithness 8-9 years after planting, and in Grampian 11-12 years after. On areas adjoining plantation < 8 years old in Caithness, densities and breeding success of waders and red grouse did not differ significantly from those on open moorland areas far from trees. However, next to older trees the densities of some waders were lower, and breeding success of golden plover <i>Plurialis apricaria</i> and red grouse lower than on open moorland. In Grampian, densities of red grouse did not differ between the different types of area, but breeding success was significantly lower on edge areas than on open moorland. Lower densities and poorer breeding in the two species mentioned above coincided with older nearby trees and taller ground vegetation. However, within areas there were no significant relationships between density and distance from the forest edge for any species, and similarly for breeding success.

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Foraging generalist predators are frequently confronted with a diversity of prey types that differ in profitability. Optimal foraging models predict that predators should select and exploit the most profitable prey types and reject unprofitable ones. The goal of this research was to evaluate the mechanisms underlying prey selection, prey exploitation and predation efficacy in the generalist predator Coleomegilla maculata lengi Timb. (Col., Coccinellidae). / The influence of prey species, prey size and predator age on predation efficacy and prey consumption by C. maculata was determined using non-choice laboratory tests. The three lepidopterous species occurring in cruciferous crops, namely, Artogeia rapae (L.), Plutella xylostella (L.) and Trichoplusia ni (Hubner), were used as prey. Results showed that, within a given prey instar, C. maculata preyed more on P. xylostella than on the other two species and that predation efficacy increased with increasing predator age. These experiments also revealed that coccinellid larvae had a higher prey weight consumption rate on intermediate-sized prey compared to smaller or larger prey even though they killed a higher number of small prey. It is suggested that this higher efficacy on prey of intermediate size could be a consequence of higher costs associated with the consumption of prey at both ends of the size spectrum. / To evaluate behavioral parameters of prey selection in C. maculata larvae, an image analysis system, initially developed for parasitoids searching for hosts, was modified. This system was programmed to locate the eggs used as prey and to detect and follow the movements of the C. maculata larval head. This user-friendly system can detect and follow the movements with less than 0.1% of error. / Using this tracking system, the discriminatory capacity and the prey selection behavior of C. maculata larvae were evaluated in choice situations in which prey differed in quality (unparasitized, parasitized, young or old T. ni eggs). Coccinellid larvae did not exhibit any preference between parasitized and unparasitized eggs of the same physiological age. However, when physiological age differed, coccinellid larvae always preferred the younger eggs despite parasitism. Longer handling time and detrimental effects on immature developmental time and survival was always observed on the less preferred egg type. / This study also revealed that coccinellid larvae can learn to gradually reject the less suitable parasitized eggs, thereby improving their prey selection behavior. It was also demonstrated that these learned behaviors could be forgotten and that previous experiences on other prey types could influence the initial preference of coccinellid larvae. This study clearly indicates that the generalist predator C. maculata can select and exploit prey according to their profitability by using discrimination and learning abilities.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1988. / Vita. Abstract. Includes bibliographical references (leaves 79-84). Also available via the Internet.

Thesis (Ph. D.)--University of Montana, 2007. / Title from title screen. Description based on contents viewed Aug. 19, 2008. Includes bibliographical references (p. 173-190).

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 80-88). Also available via the Internet.

Thesis (M.S.)--University of North Carolina Wilmington, 2009. / Title from PDF title page (February 21, 2010) Includes bibliographical references (p. 34-35)

Thesis (M.S.)--University of Wisconsin--Madison, 1970. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--Illinois State University, 1993. / Title from title page screen, viewed February 22, 2006. Dissertation Committee: Steven A. Juliano (chair), Scott K. Sakaluk, Douglas W. Whitman, James V. Robinson, Angelo P. Capparella. Includes bibliographical references (leaves 136-144) and abstract. Also available in print.

Thesis (Ph.D.)--Montana State University--Bozeman, 2006. / Typescript. Chairperson, Graduate Committee: Scott Creel. Includes bibliographical references (leaves 68-75).