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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Nest Recognition of Black-naped Tern (Sterna sumatrana) and Roseate Tern (Sterna dougallii)

Lin, Yu-hung 20 January 2009 (has links)
Terns usually will aggregate in the same reproduction area during breeding season. The color pattern of eggs may match the background, and it is important for breeding adults to distinguish their own eggs, especially in colonies with high density. This research was carried out at three islands, Huolung Shoal, Baisha and Jishan Islets of Penghu from May to August of 2007 and 2008. The experiment was divided into three parts, egg moving (EM) experiment, nest modification (NM) experiment and egg switching (ES) experiment. Terns spent more time for searching their own nests of each of the experiment situation. In the EM experiment 69.7% Black-naped Tern adults settled on original nests without eggs in 2007; 52.0% Roseate Tern in 2007 and 29.6 % in 2008 did the same. In the NM experiment, the behavior patterns of returning adults were significantly different between each operation and the control group. Adults were confused by the interference of the experimental conditions. In some occasions, adults settled on incorrect eggs quietly in ES experiment. In conclusion, terns have low ability of egg recognition but high ability of nest recognition. Terns presumably can recognize nests with the nearby environmental landmarks, but not be able to recognize eggs.
2

Ecology of nesting waterfowl in the Missouri coteau of southern Saskatchewan

Leitch, William G., 1914- 30 March 1952 (has links)
Expanding populations, more leisure time and increased standards of living since World War II, have resulted in an ever increasing demand in the United States and Canada for outdoor recreation in the form of hunting and fishing... In the course of the investigation it was necessary to census the nesting population, find nests, and search for broods. It was apparent that these observations were important in themselves, and the investigation soon expanded into a study of the ecology of waterfowl in the area, of which, in the end, the orginal objective became a minor part...
3

Ecology of nesting waterfowl in the Missouri coteau of southern Saskatchewan

Leitch, William G., 1914- 30 March 1952 (has links)
Expanding populations, more leisure time and increased standards of living since World War II, have resulted in an ever increasing demand in the United States and Canada for outdoor recreation in the form of hunting and fishing... In the course of the investigation it was necessary to census the nesting population, find nests, and search for broods. It was apparent that these observations were important in themselves, and the investigation soon expanded into a study of the ecology of waterfowl in the area, of which, in the end, the orginal objective became a minor part...
4

A spatial model of waterfowl nest site selection in grassland nesting cover

Pool, Duane Bruce. January 2004 (has links)
Thesis (Ph. D.)--Colorado State University, 2004. / Includes bibliographical references.
5

Evaluation des Legeverhaltens bei Legehennen und Untersuchungen zur Nestwahl unter Berücksichtigung der Motivation für den Nestzugang zu arbeiten

Kruschwitz, Anja January 2008 (has links)
Zugl.: Leipzig, Univ., Diss., 2008
6

Building behaviour and the control of nest climate in Acromyrmex leaf-cutting ants

Bollazzi Sosa, Leonardo Martin January 2008 (has links)
Zsfassung in dt. Sprache. - Würzburg, Univ., Diss., 2008
7

Diurnal bird use of snags on clearcuts in central coastal Oregon /

Schreiber, Barry. January 1987 (has links)
Thesis (M.S.)--Oregon State University, 1988. / Typescript (photocopy). Includes bibliographical references (leaves 60-63). Also available on the World Wide Web.
8

Nesting ecology of mourning doves in changing urban landscapes

Munoz, Anna Maria 17 February 2005 (has links)
Texas A&M University (TAMU) supports a substantial breeding population of mourning doves (Zenaida macroura) with one of the highest nest densities in Texas. There has been a long history of mourning dove research on the TAMU Campus, with initial population studies conducted in the 1950’s, and the most recent studies occurring in the 1980’s. The TAMU Campus and surrounding areas have experienced substantial changes associated with urbanization and expansion over the last 50 years, altering mourning dove habitat on and around campus. The objective of this study was to examine mourning dove nesting and production in an urban setting and determine how microhabitat and landscape features affect nest-site selection and nest success. Specifically, I (1) examined trends in mourning dove nesting density and nest success on the TAMU Campus, and (2) identified important microhabitat and landscape features associated with nest-site selection and nesting success. Mourning dove nests were located by systematically searching potential nest sites on a weekly basis from the late-March through mid-September. Nests were monitored until they either failed or successfully fledged at least 1 young. A total of 778 nests was located and monitored on campus. All nest locations were entered into ArcView GIS. An equal number of nests were randomly generated in ArcView and assigned to non-nest trees to evaluate habitat variables associated with nest-site selection for mourning doves. Binary logistic regression was used to evaluate the significance of microhabitat and landscape variables to nest-site selection and nest success. Comparisons with data collected in 1950, 1978, and 1979 showed relatively similar nesting densities, but a significant decrease in nest success over time. A comparison of microhabitat features between actual nest trees and random locations (non-nest trees) indicated increasing values of tree diameter at breast height and tree species were important predictors of mourning dove nest-site selection. Landscape features found important in dove nest-site selection were proximity to open fields, roads, and buildings. Proximity to roads and buildings also were significant predictors of nest success. Combining significant microhabitat and landscape variables for nest-site selection increased the predictability of the model indicating a possible hierarchical nest-site selection strategy.
9

Analysis of the Black-capped Vireo and White-eyed Vireo Nest Predator assemblages

Conkling, Tara J. 2010 May 1900 (has links)
Predation is the leading cause of nest failure in songbirds. My study identified nest predators of black-capped vireos and white-eyed vireos, quantified the activity of potential predator species, examined the relationships between vegetation and nest predators, and examined the relationship between nest predation and parasitism by brown-headed cowbirds. In 2008 and 2009 I monitored black-capped and white-eyed vireo nests on privately-owned properties in Coryell County and black-capped vireo nests on Kerr WMA in Kerr County and at Devils River State Natural Area in Val Verde County (2009 only). I monitored vireo nests using a video camera system to identify predators and nest fate. I also collected at-nest vegetation measurements including nest height, distance to nearest habitat edge, and nest concealment. Additionally, I sampled potential predator activity at a subset of black-capped vireo and white-eyed vireo nests in Coryell County using camera-trap bait stations and herptofaunal traps. I monitored 117 black-capped vireo nests and 54 white-eyed vireo nests. Forty-two percent of black-capped vireo and 35% of white-eyed vireo nests failed due to predation. I recorded >10 total predator species and 37 black-capped vireo and 15 white-eyed vireo nest predation events. Snakes (35%) and cowbirds (29%) were the most frequently identified nest predators; however, major predator species varied by location. I observed no significant relationship between nest fate (fledge vs. fail) and nest concealment or distance to edge for either vireo species. Nest height, concealment and distance to edge may relate to predator species in Coryell Co. for snake species, and Kerr for avian species. Additionally, I observed no difference between the predator activity and the fate of the nest. Both vireos have multiple nest predator species. Additionally, multiple cowbird predations demonstrate this species may have multi-level impacts on vireo productivity, even with active cowbird management. Vegetation structure and concealment may also affect predator species. However, the activity of other predator species near active nests may not negatively affect nest success.
10

Nest site selection patterns of dabbling ducks in response to variation in predation pressure : an experimental study

Lester, Vance G 15 December 2004
Nesting success is an important vital rate affecting the reproductive fitness of birds, and predation typically is the single most important factor affecting nesting success. Presumably, birds should nest in locations that maximize nest survival. If specific nest characteristics increase the probability that a nest will hatch, natural (phenotypic) selection could favour use of sites with these features, producing nonrandom patterns of nest site use. Alternatively, birds that are highly selective in nest site choices might be at a disadvantage if predators learn to forage preferentially in these locations and improve their efficiency in depredating nests; in this case, random nesting patterns could be favoured. Finally, it has been hypothesized that predation pressure can influence nest site selection patterns of entire bird communities. If predators develop a search image to hunt for bird nests, then nests that are most similar to each other, irrespective of species, should sustain higher mortality. To evaluate these hypotheses, I quantified nest site selection patterns of multiple species of ground-nesting dabbling ducks in areas where predation pressure was normally high, and compared these patterns to those on areas where predation was relaxed. Predation pressure was experimentally reduced by removing common predators of duck nests and females (mainly red foxes, coyotes, skunks and raccoons) on some study areas and not on others (controls). Predator removal and natural causes produced a 10-fold difference in duck nesting across study sites, allowing for investigation of effects of predation pressure on nest site selection of ducks. Coarse scale habitat selection patterns were similar to results reported in previous studies; blue-winged teal and northern shoveler were found more often in native grassland than in other habitat types, while gadwall and mallard nests occurred more frequently in shrub patches when compared with other habitat patches. A difference in nest site characteristics was observed between hatched and depredated nests for gadwall and northern shoveler but not for blue-winged teal and mallard. However, in all species, the nest site selection patterns were non-random. Thus, the process of nest predation did not shape patterns of nest site choice. Contrary to predictions, inter-specific overlap in nest site features was not related to predation pressure: nests that overlapped most with features of other species did not suffer higher predation, nor did inter-specific overlap in nest characteristics decrease during the nesting season. These findings were inconsistent with the hypothesis that community-level patterns of nest site use are differentiated as a result of predation pressure. Long-term work on nest site use by individually marked females of numerous ground-nesting bird species would be informative, as would experimental studies of other hypotheses about factors affecting nest site choices in birds.

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