This study addresses the question: are seabirds digestive opportunists or specialists? The extent of specialization in seabird digestive processes to different diets and foraging methods, is investigated experimentally. Gut passage rates of different food types of tested in vitro digestibility may reflect dietary specialization, with favoured prey types excreted more rapidly than less frequently encountered prey. Mean retention times of solid digesta are significantly correlated with foraging trip duration, and with gut length. Gut length and volume in tum scale with body mass. Assimilation efficiencies of various dietary components are not predictable purely on the basis of food composition, and show a high degree of inter- and intraspecific variability. Energy assimilation efficiency does not reflect dietary specialization, and may be maintained at approximately 75% regardless of diet. Assimilation efficiency is, however, temporarily elevated in energetically-stressed birds, such as penguins that have recently completed moult. Digestive specializations are reflected in seabirds' abilities to assimilate substances specific to certain prey organisms. Unlike most terrestrial vertebrates, seabirds are able to digest wax esters, compounds important in marine food webs. Procellariiforms exhibit unique gastric adaptations facilitating extended foraging trips and efficient transport of food to their young, both important advantages for predators exploiting patchy and unpredictable food resources. Seabirds which naturally feed on crustaceans secrete the specific enzyme chitinase from their gastric mucosae, permitting digestion of the chitinous exoskeleton of the prey. The ability to secrete this enzyme is probably a retained ancestral trait rather than a newly evolved one, and may have been lost by seabirds that do not prey on crustaceans. Differences between penguins and procellarids reflect unique adaptations to the different foraging techniques employed by these two families. The synthesis of the thesis explores the adaptive significance of gut passage rate and allometry of the gut in relation to the two predominant foraging techniques employed by seabirds: long- distance aerial soaring and subsurface swimming. Scaling of seabird gut size may play an important role in the interplay between metabolic rate, the energy demands of foraging, and digestive physiology. The allometric approach taken here is potentially useful for studies of seabird digestion, and has application in studies linking the evolution of avian body size, and foraging ecology.

City greenspaces are often considered as refuges for wildlife living in the urban area.At the same time, the original function of greenspaces is providing relaxing places forpeople. So, to provide suitable area for both humans and wildlife in the city, it isimportant to learn about the preference to city greenspace design by humans and birds.In this study, I selected 45 city greenspaces from Stockholm and Uppsala, Sweden, andused opportunistic citizen science bird records, environmental parameters ofgreenspaces analyzed by GIS and an online social survey to compare the preference ofbirds (using bird diversity as a proxy for preference) and humans living in urban areawith respect to certain environmental parameters of city greenspaces. I found that bothpeople and birds prefer greenspaces with large area, and some water area in or aroundgreenspace. I also found some conflicting preferences in that people more preferredgreenspaces near the city center but bird diversity was higher in greenspaces fartherfrom the city center. These results might bring new mind for urban ecology researchand ecofriendly city greenspace design. Greenspaces with larger area and water areawould be preferred by both people and birds.

Feeding ecology and trophic interactions of six species of wading birds were explored through a combined analysis of stable isotope profiles and endoparasite communities. Stable isotopes broadly characterize the feeding preferences and geographic information, while parasite communities reflect long-term trends in feeding ecology. Deceased birds were obtained from four South Florida wildlife rehabilitation organizations. Of the 81 birds dissected, 73 contained parasites. Parasites were predominately found within the gastrointestinal tract. Host and range extensions were noted for several parasite taxa. Bird host species had a significant effect on the parasite community (P=0.001) while wildlife center location and maturity status did not. Stable nitrogen (δ15N) values for pectoral muscle tissues, representing approximately 24 days, ranged from 6.44 to 13.48‰ while stable carbon (δ13C) values ranged from -33.39 to -11.66‰. δ13C varied significantly among location (P=0.0002) and δ15N varied significantly among species (P15N and δ13C was analyzed in combination; bird species (P=0.001) and location (P=0.001) were significantly different. By using this combined approach of stable isotope analysis and parasite identification, it was possible to elucidate more components of bird feeding ecology. Stable isotope analysis provided knowledge on trophic interactions based on δ15N values, while δ13C was used to determine the differences in geographic foraging location. As endoparasites are acquired trophically via food-web interactions, identifying the parasite community allowed for trophic links to be drawn between organisms present within the same environment. Combining these two techniques allows for an abundance of information on feeding ecology and trophic interactions to be obtained.

The purpose of the work leading to the writing of the thesis was two fold: (1) to survey birds of Northern California for hemoprotozoa of the genera Haemoproteus, Leucocytozoon, and Trypanosoma, and (2) to construct an up-to-date check-list of the Haemoproteus, Leucocytozoon, and Trypanosoma parasites of birds of North America.

No description available.

The artist discusses the search for identity which underlies her Master of Fine Arts exhibition, Eulogy, hosted by the Carroll Reece Museum on the campus of East Tennessee Sate University, Johnson City, Tennessee, from March 8 to May 6, 2011. This exhibit contains works which explore the artist's relationship with the natural world, ornithology, philosophy, psychology, poetry, and related personal influences. The artist's thesis work consists of paintings, drawings, and photographs. The artist references her own investigation of poetry, philosophy, psychology, and personal history which have shaped a private sense of awareness. Also reviewed are the influences of artists such as Alexander Marshall, William Morris, Charles Burchfield, Rosamond Purcell, and Kiki Smith; the poetry of Rainer Maria Rilke and writings of Loren Eiseley; the ideas of philosophers G. W. F. Hegel and Slavoj Žižek, and art historian James Elkins.

Social information affects the movement decisions of animals and is often an essential factor in habitat selection. Social information should be especially relevant to long-distance migrating birds that navigate over long distances through unfamiliar habitats to find resources to survive. This information likely varies in both availability and importance at the different spatial scales relevant to migrating birds. Using the common yellowthroat as a case study, I tested whether cues might be available in the songs of locally breeding birds at the continental, within-site, and within-territory scales. At the continental scale, I described the geographic variation in song among genetic groups and subspecies, which may provide useful information for migrants navigating across the continent. I found differences in song structure including the duration of silences between notes, number of notes, and bandwidths which might provide cues. Additionally, bandwidth was related to habitat density. At the within-site scale, I tested whether there is a relationship between song, habitat structure, habitat quality, bird size, and bird quality. I found no evidence that song variation is an available source of information about habitat type or quality to migrants exploring habitat variation at the within-site scale. At the same scale, I tested whether migrating common yellowthroats use the presence of song to find habitat by broadcasting song recordings in suitable and unsuitable habitat patches, but did not lure any migrants. However, when I compared the distance between local singing males and the capture locations of migrant common yellowthroat in a passive mist-netting array to the distances expected by chance, I found that migrants were further away from singing local males than expected, perhaps to avoid costly aggressive interactions. At the within-territory scale, I tested whether a singer's location is predictive of microhabitat structure or food abundance, and whether song rate or duration is predictive of a local male's activities. I found that the location of a singing bird may provide migrants with information about the location of food and structurally denser habitat. Song variation may also predict the likelihood of attack should a migrant intrude in the local male's territory.

Information on the nesting of the White-faced Ibis (Plegadis chihi) in Utah County is presented for the first time. Nests built in hardstem bulrush (Sciprus acutus) settled from an average height of 120.8cm on June 9 to 93.6cm on June 27, 1971. Nest spacing ranged from 2m to 9m, averaging 4.6m. Invertebrates of the class Arachnida and the insect orders Coleoptera, Homoptera, Lepidoptera, and Thysanoptera were collected in a Berlese funnel. Average clutch size was 3.17. Egg length and width averaged 51.40mm X 36.75mm. Average volume was 36.93cc. In 21 study nests, 45.8 percent of the eggs hatched, beginning on June 8 and ending on June 27. The young weighed approximately 26gm at hatching, with tarsometatarsus and bill each 15mm long. These increased to 400gm, 70mm, and 45mm, respectively, in 15 days. Feather shaft had grown to over 100mm. Major food items of the nestlings were larvae of the insect families Dytiscidae, Hydrophylidae (O. Coleoptera) and Stratiomyidae (O. Diptera). Ectoparasites collected were a louse, plegadiphilus plegadis, and three unidentified flies.

During the period of October to April of the winter of 1950-51, an ecological study was undertaken of a population or passerine birds wintering in a segment of the Utah Lake Shore. Available winter weather data indicated that although such factors as precipitation, temperature, and wind may often be severe, they are not critical enough to prevent a fairly large population of passerine birds from spending the winter months in the study locale. Five fairly distinct plant communities can be recognized in the area. There is evidence which indicates that certain passerine bird species are especially dependent on a particular type or types of vegetation. The plant communities produce ample amounts of food to meet the requirements of wintering birds. It was found that nine passerine species play an important part in the natural economy of this area in winter. Such species as the song sparrow and marsh wren are relatively stable in their numbers and occurrence, and have number per hour ratings which are significant. Other birds, among them the redwing and crow occur here in great numbers but fluctuate widely in day by day totals. Their number per hour ratings are comparatively meaningless as an index to relative numbers, but are significant in that they indicate different modes of habit of these birds. The thesis is intended to be a contribution to our knowledge of the wintering habits of perching birds in lakeside areas or central Utah.

Due to a lack of taxonomic and distributional information concerning the Common Crow Corvus brachryhynchos Brehm inhabiting the Great Basin of North America, Johnston (1961) in one of the most recent revisions on crows, was unable to include this area in his work. Between 1965 and 1967, field trips were taken throughout the Great Basin to secure specims, and to determine to what extent the area was being utilized by crows. Ecological information such as habitat prference, nesting behavior, and interactions with other species was collected where possible. Forty-eight birds were collected from the Great Basin. From a comparison of data from these birds with data from crows from other areas of North America, it was concluded that the Great Basin crows are the eastern variety Corvus brachyrhynchos brachyrhynchos Brehm. Summer and winter distribution is similar in that river valleys with meandering streams, which support willow thickets and nearby meadows, are primarily utilized. A difference in winter distribution with that of the summer is the occurrence of large concentrations of crows in Utah during the winter. Crows were found to have interactions with magpies and starlings. These consisted mainly of crows utilizing unfinished magpie nets, and stealing food scraps from starlings. The crow causes very little damage to crops in the Great Basin and is probably an asset because of the recreation it affords the local sportsmen, rather than an economic problem.