No description available.

Sleep loss is known to trigger an inflammatory response and increase serum corticosterone in both human and murine models. However, very little evidence is available on the potential effects of sleep loss in avian models. This study aims to construct a profile using cytokine gene expression data to determine how birds respond to sleep loss in a controlled environment. I investigated changes in pro-inflammatory (IL-1β and IL-6) and anti-inflammatory (IL-10) cytokine gene expression in the periphery (fat, liver, spleen, and heart) and brain (hypothalamus, hippocampus, and apical hyperpallium) in zebra finches exposed to a novel sleep fragmentation method. Serum corticosterone, body mass, and behavioral profiles also were assessed. Sleep was interrupted periodically for over 12 hours using a sleep fragmentation chamber, which was modified from those typically used in murine studies. This chamber contained a sweeping wire bar that moved the distance of the cage at 2-minute intervals. I predicted that sleep fragmented birds would exhibit elevated pro-inflammatory and reduced anti-inflammatory gene expression relative to those birds that were not sleep fragmented. In addition, I predicted a decrease in body mass and an increase in serum corticosterone levels because of sleep fragmentation. Contrary to my predictions, sleep fragmentation resulted in lower levels of IL-1β in the apical hyperpallium, but lower levels of IL- 10 in the hippocampus. No differences were detected in the adipose tissue of individuals exposed to sleep loss. Sleep fragmentation resulted in an increase in percent body mass lost. Serum corticosterone levels did not differ across groups. These data provide preliminary insight into the inflammatory response that is seen as a result of sleep loss in an avian model. Overall, it appears that as compared to some mammals such as murine rodents, birds are not as susceptible to sleep loss.

No description available.

The periodic fluctuations in numbers of red grouse (<I>Lagopus lagopus scoticus </I>(Lath.)) populations in Scotland and northern England remain a puzzle to population ecologists despite sustained research. Other workers have suggested that territoriality, philopatry and kin selection, as expressed in the differential behaviour between kin and non-kin, can, through their effects on the efficiency of space use, combine to cause cyclic dynamics. However, since the first preliminary formulation of the hypothesis in 1990, little modelling work has been done on the subject. In this thesis, I present a series of models which explore the plausibility of the kin-selection hypothesis for red grouse populations under different assumption regimes. I first develop, analyse and validate a simple, deterministic model using functions of age structure as indexes of the social and, due to philopatry, spatial attributes of the population. A control version of the model is incapable of cyclic dynamics, while a modification, containing the assumed effects of kin selection, produces cycles of realistic period and amplitude. Parameterisation of the model with field data from two studies in north-east Scotland yields output which resembles the observed dynamics. A more detailed study of the possible effects of kin selection and philopatry on individual requirements for space yields a parameterised response function which is then used to study the dynamics of individual family clusters. A model of the relatively short-term process of family cluster formation demonstrates that continuous changes in crowding may have a discontinuous effect on the ability of clusters to form. A socially and spatially explicit simulation model is finally developed to examine the relative importance of these factors in the long-term dynamics. Based on its results, I conclude that spatial heterogeneity in the activity of animals, caused by clustering, is sufficient to produce cycles and that variations in territorial requirements due to differential behaviour between kin and non-kin can have a secondary, amplifying role in the process.

Proefschrift--Leyden. / "Stellingen": [2] p. inserted. Bibliography: p. [188]-217.

Understanding the processes and mechanisms governing animal movement is a fundamental goal in ecology. Processes driving movement can occur across multiple spatiotemporal scales and have important consequences for the structure and dynamics of populations, communities and ecosystems. The study of movement provides insights into the ecological resources and habitats necessary for persistence of species and communities. It also provides a theoretical and applied basis from which to formulate informed conservation plans. Waterbirds in semiarid southern Africa are an ideal study group for understanding interactions between movement and environmental factors because they exhibit a wide range of movement strategies and are located within a landscape in which resources are characterised by high levels of spatiotemporal variability. Emphasis has been placed on understanding movement phenomena from individually-tracked animals, but cases which consider this approach in conjunction with traditional community ecology perspectives are rare. In this thesis I explored questions of movement in both individuals and communities, and argue that an integrated multi-scale approach is necessary to advance our broader understanding of movement in waterbirds. In the first part of the study I addressed an individual-level movement perspective. I used fine-scale telemetry data from 35 individually tracked Egyptian Geese Alopochenaegyptiaca and Red-billed Teal Anas erythrorhyncha with novel analytical techniques to explore questions of trade-offs in habitat selection, functional responses and whether movement responses to landscape resources are reactive or prescient. My findings suggested that, at the home-range scale, both forage optimisation and predation risk were limiting factors of movement and habitat selection of Egyptian Geese. I also showed for the first time that waterbirds exhibit functional responses in relation to changes in the availability of habitat types. I subsequently showed that the proximate drivers of waterfowl movement are the dynamics of rainfall and primary productivity. Egyptian Geese and Red-billed Teal were able to perceive and respond to temporal shifts in resource conditions prior to habitat patch occupation. This in turn suggested that their movements in semi-arid landscapes are underpinned by an intimate knowledge of the local environment and that waterfowl exhibit a complex behavioural movement strategy. In the second part of the study I used waterbird count data collected from wetlands in KwaZulu-Natal, South Africa, to address the community-level movement perspective.

Since the square-foot bottom sampler was described by Surber it has been the principle instrument used for quantitative studies of the bottom fauna in riffle areas of streams. However, little has been written concerning the actual number of square-foot samples necessary to describe stream bottom fauna in terms of the number or volume of organisms.

Storm-created nesting habitat and low wave energy moist sediment habitat (MOSH), such as intertidal sandflats, have long been considered important to the recovery of the piping plover (Charadrius melodus), a federally threatened shorebird. Beach renourishment is a common practice on the U.S. Atlantic Coast for the protection of human property from storms, but it also prevents normal MOSH formation. We examined factors limiting piping plover nesting pair density and reproductive output on Atlantic Barrier Islands, 2001-2004, including one site that had been breached by a storm in 1992, and subsequently repaired and renourished by the U.S. Army Corps of Engineers. We also investigated the short-term impact of beach renourishment at these sites. Number of pairs at a site increased with beach area. Pair density increased with MOSH availability at the site level. Home range size increased as the distance from plover nests to MOSH increased. Home range size was smaller for plovers with higher foraging rates in the territory-establishment period, but this effect was most likely independent of distance to MOSH. Reproductive output was not apparently related to availability of MOSH to adults or broods, and was limited by predation. Habitat widths, prey abundance, and brood habitat selection changed at two of our sites after renourishment. However, similar changes occurred in reference areas. Other research shows that in addition to long-term loss of storm-created features, beach stabilization can lead to loss of habitat and low reproductive success due to human development and an increased presence of introduced predators. Management for recovery of this species should thus include permitting natural storm-mediated habitat creation to occur where feasible. However, since we found no direct negative short-term impact of renourishment on prey or habitat availability, habitat restoration via renourishment of eroded beaches could be a viable strategy for plover recovery, if negative indirect short and long-term effects are mitigated. Restoration projects should include restoration or creation of MOSH adjacent to nesting habitat, because MOSH attracts a high density of pairs and to offset long-term loss of storm-created habitat. Human disturbance and predation must also be controlled at restoration sites. / Ph. D.

In this project I explore the development of bird illustrations in early American natural history publication. I follow three groups in Philadelphia from 1812 to 1858: institutions, artist-naturalists, and printmakers. Each of these groups modeled a certain normative vision of illustration, promoting, producing, and publishing images that reflected their senses of what constituted good illustration. I argue that no single set of actors in this narrative did work that would become the ultimate standard-bearer for ornithological illustration; rather, all of them negotiated the conflicting interests of their own work as positioned against, or alongside, those who had come before. Their diverse intentions, aesthetic and practical, sat prominently in their separate visions of drawing birds; utility, artistry, and feasibility of the images directed the creation of the illustrations. How they used their ideal ways of depicting birds changed the ways that their successors would confront the practice of illustrating birds. / Master of Science

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.