Riparian zones are a characteristic component of many landscapes throughout the world and increasingly are valued as key areas for biodiversity conservation. Their importance for bird communities has been well recognised in semi-arid environments and in modified landscapes where there is a marked contrast between riparian and adjacent non-riparian vegetation. The value of riparian zones in largely intact landscapes with continuous vegetation cover is less well understood. This research examined the importance of riparian habitats for avifauna conservation by investigating the ecological interactions contributing to the pattern of bird assemblages in riparian and adjacent non-riparian habitats. Specifically, the focus is on the bird assemblages of riparian zones and those of adjacent non-riparian vegetation types and the influence that associated differences in resource availabilities, habitat structure and conditions have on observed patterns. This study was conducted in the foothill forests of the Victorian Highlands, south-east Australia. Mixed-species eucalypt (genus Eucalyptus) forests dominate the vegetation of this region. Site selection was based on the occurrence of suitable riparian habitat interspersed within extensive, relatively undisturbed (i.e. no recent timber harvesting or fire events) forest mosaics. A series of 30 paired riparian and non-riparian sites were established among six stream systems in three forest areas (Bunyip State Park, Kinglake National Park and Marysville State Forest). Riparian sites were positioned alongside the stream and the non-riparian partner site was positioned on a facing slope at a distance of approximately 750 m. Bird surveys were carried out during 29 visits to each site between July 2001 and December 2002. Riparian sites were floristically distinct from non-riparian sites and had a more complex vegetation structure, including a mid-storey tree layer mostly absent from non-riparian sites, extensive fine litter and coarse woody debris, and dense ground-layer vegetation (e.g. sedges and ground ferns). The characteristic features of non-riparian habitats included a relatively dense canopy cover, a ground layer dominated by grasses and fine litter, and a high density of canopy-forming trees in the smaller size-classes. Riparian zones supported a significantly greater species richness, abundance and diversity of birds when compared to non-riparian habitats. The composition of bird assemblages differed significantly between riparian and non-riparian habitats, with riparian assemblages displaying a higher level of similarity among sites. The strongest contributors to observed dissimilarities between habitat types included species that occurred exclusively in either habitat type or species with large contrasts in abundance between habitat types. Much of the avifauna (36%) of the study area is composed of species that are common and widespread in south-east Australia (i.e. forest generalists). Riparian habitats were characterised by a suite of species more typical of wetter forest types in south-east Australia and many of these species had a restricted distribution in the forest mosaic. Some species (7%) occurred exclusively in riparian habitats (i.e. riparian selective species) while others (43%) were strongly linked to these habitats (i.e. riparian associated species). A smaller proportion of species occurred exclusively (2%) in non-riparian habitats (i.e. non-riparian selective species) or were strongly linked to these habitats (10%; i.e. non-riparian associated species). To examine the seasonal dynamics of assemblages, the variation through time in species richness, abundance and composition was compared between riparian and non-riparian sites. Riparian assemblages supported greater richness and abundance, and displayed less variation in these parameters, than non-riparian assemblages at all times. The species composition of riparian assemblages was distinct from non-riparian assemblages throughout the annual cycle. An influx of seasonal migrants elevated species richness and abundance in the forest landscape during spring and summer. The large-scale movement pattern (e.g. coastal migrant, inland migrant) adopted by migrating species was associated with their preference for riparian or non-riparian habitats in the landscape. Species which migrate north-south along the east coast of mainland Australia (i.e. coastal migrants) used riparian zones disproportionately; eight of eleven species were riparian associated species. Species which migrate north-south through inland Australia (i.e. inland migrants) were mostly associated with non-riparian habitats. The significant differences in the dynamics of community structure between riparian and non-riparian assemblages shows that there is a disproportionate use of riparian zones across the landscape and that they provide higher quality habitat for birds throughout the annual cycle. To examine the ecological mechanisms by which riparian assemblages are richer and support more individual birds, the number of ecological groups (foraging, nest-type and body mass groups) represented, and the species richness of these groups, was compared between riparian and non-riparian assemblages. The structurally complex vegetation and distinctive habitat features (e.g. aquatic environments, damp sheltered litter) provided in the riparian zone, resulted in the consistent addition of ecological groups to riparian assemblages (e.g. sheltered ground – invertebrates foraging group) compared with non-riparian assemblages. Greater species richness was accommodated in most foraging, nest-type and body mass groups in riparian than non-riparian assemblages. Riparian zones facilitated greater richness within ecological groups by providing conditions (i.e. more types of resources and greater abundance of resources) that promoted ecological segregation between ecologically similar species. For a set of commonly observed species, significant differences in their use of structural features, substrates and heights were registered between riparian and non-riparian habitats. The availability and dynamics of resources in riparian and non-riparian habitats were examined to determine if there is differential availability of particular resources, or in their temporal availability, throughout the annual cycle. Riparian zones supported more abundant and temporally reliable eucalypt flowering (i.e. nectar) than non-riparian habitats throughout the annual cycle. Riparian zones also supported an extensive loose bark resource (an important microhabitat for invertebrates) including more peeling bark and hanging bark throughout the year than at non-riparian sites. The productivity of eucalypts differed between habitat types, being higher in riparian zones at most times for all eucalypts combined, and for some species (e.g. Narrow-leaved Peppermint Eucalyptus radiata). Non-riparian habitats provided an abundant nectar resource (i.e. shrub flowering) at particular periods in the annual cycle. Birds showed clear relationships with the availability of specific food (i.e. nectar) and foraging resources (i.e. loose bark). The demonstration of a greater abundance of resources and higher primary productivity in riparian zones is consistent with the hypothesis that these linear strips that occupy only a small proportion of the landscape have a disproportionately high value for birds. Riparian zones in continuous eucalypt forest provide high quality habitats that contribute to the diversity of habitats and resources available to birds in the forest mosaic, with positive benefits for the landscape-level species pool. Despite riparian and non-riparian habitat supporting distinct assemblages of birds, strong linkages are maintained along the riparian-upslope gradient. Clearly, the maintenance of diverse and sustainable assemblages of birds in forest landscapes depends on complementary management of both riparian and non-riparian vegetation.

Thesis (Ph.D.)--York University, 2004. Graduate Programme in Biology. / Typescript. Includes bibliographical references (leaves 109-136). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pNQ99143

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 85-88). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 85-88). Also available on the Internet.

Thesis (Ph. D.)--Florida State University, 2004. / Advisor: Dr. Frank Johnson, Florida State University, College of Arts and Sciences, Department of Psychology. Title and description from dissertation home page (viewed June 16, 2004). Includes bibliographical references.

Thesis (M.E.S.)--The Evergreen State College, 2009. / Title from title screen (viewed 2/24/2010). Includes bibliographical references (leaves 98-107).

No description available.

Field studies were conducted with "three species of passerine, in order to investigate the possibility that an energetic constraint limits reproduction during incubation. Swallows (Hirundo rustiea), Dippers (Cinelus einelus) and Great Tits (Parus nlajor) were studied at sites in Central Scotland. All three species exhibit gynelateral intermittent incubation, so time and energy must be allocated between the conflicting demands of reproduction and selfmaintenance. An assessment of incubation ability in the Swallow was conducted by the manipulation of clutch size during incubation. There was evidence of a clutch size dependent cost, as the duration of the incubation period was prolonged for enlarged (15.6d) compared to reduced (14.8d) clutches. The proportion of eggs hatching successfully was also lower in enlarged (81 %) than in reduced (92%) clutches, though enlarged clutches still produced the greatest number of hatched young. Clutch manipulation did not influence patterns of nest attendance, or female body condition. No effects of incubation effort were detected posthatch on either parents or offspring. The effects of clutch size on field metabolism during incubation were investigated in the Dipper. Clutch size was manipulated and energy use measured by means of the doubly labelled water technique. The results were combined with previous data collected for incubating Dippers. The field metabolic rate of 33 incubating females averaged 5.41 ± 1.34 cm3 CO2 g-l h-1 , equivalent to a daily energy expenditure of 211.52" ± 51.25kJ ind-1 d-1 , e.3 times the basal metabolic rate. Clutch enlargement resulted in an increase in energy use to 4-6 times basal metabolism for some birds," but not for others. While the mean energy use did not differ between groups, the variation amongst birds was significantly greater for enlarged than control clutches. Energy use was also influenced by river flow rates, the duration of incubation sessions and behaviour during incubation recesses. Manipulation of the energy budget of incubating Great Tits was achieved by the reduction of thermoregulatory demands. Treated nest boxes were supplied with additional heat during the hours of darkness, resulting in an elevation of nest air temperature of e.4°C above the corresponding temperature for a control group, lasting for a period of 9 hours. This produced an estimated energetic saving of 10kJ per night. Heated birds increased the duration of both the ~period of continuous incubation overnight and of incubation sessions throughout the following day, resulting in an additional 51 minutes per day spent incubating compared to the control group. The metabolic rate of22 incubating Great Tits was 7.79 ± 2.43 cm3 C02 g-1 h- 1 , or 106.4 ± 32.2 kJ ind-1 d- 1 , equivalent to e.3 times basal metabolism. Energy use escalated for control, but not for heated birds at low ambient temperatures. The importance of reserve storage and utilisation, and of provisioning by the mate were evaluated in each species. A combined hypothesis was proposed to account for body condition during incubation, incorporating elements of programmed reserve utilisation, mass adjustment, maintenance of an insurance reserve and reproductive stress. In summary, the study found "evidence of an energetic constraint acting during incubation in these species." Energy use increased in a probabilistic manner with increasing clutch size, such that birds with large clutches increased their risk of being unable to incubate the entire clutch successfully. It was suggested that such a constraint could contribute to the determination of an upper limit for avian clutch size.

No description available.

No description available.