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Habitat requirements and habitat use for Pseudophryne australis and Heleioporus australiacus were investigated to aid management of these threatened frogs around Sydney, Australia. Much of the work focussed on roads, commonly encountered features in the habitat of both species. The habitat requirements based on locality records of both frogs in the Sydney Basin were investigated at four spatial scales. Both species are habitat specialists. They showed a strong geological association with Hawkesbury Sandstone and occupy upper topographic areas with ephemeral watercourses of gentle gradients. Both frogs occur predominantly in areas of higher precipitation and milder temperature regimes compared to averages representative of the region. Leaf litter is an important feature of P. australis breeding sites, whereas H australiacus generally associate with crayfish burrows. Both species are dependent on natural vegetation with a complex structure. H australiacus have a relatively long larval period (3 - 12 months) and breed in ephemeral pools, exposing their tadpoles to the risk of dying due to early pond drying. In the laboratory, tadpoles responded to decreasing water levels by shortening their larval periods and metamorphosing earlier than siblings held at constant water level. Despite this plastic response, a number of pools in the field failed to produce metamorphs due to early drying, an observation also made on P. australis. Regular monitoring of breeding sites revealed increased reproductive success away from roads for both species probably because of relatively longer hydroperiods. Spatial distributions and associations with habitat features, and movement patterns of both frogs were further investigated using mark-recapture methods. Both species showed strong site fidelity. P. australis formed small aggregations and predominantly selected leaf litter piles despite their relatively low availability. Leaf litter piles in creeks moved over time and the animals moved with these piles. In contrast, H australiacus individuals formed no aggregations and showed no preference for any available structural vegetation type. Locations of individuals were independent of relative distances to creeks and artificial drains, but males appeared to be more common near culverts. However, individuals were randomly distributed in space and nearest-neighbour distances were high relative to individual movement distances, suggesting minimal overlap between relatively large home ranges. Radio-telemetry demonstrated that some H australiacus individuals burrow in the road environment. There they would be at risk of being dug up and possibly injured during road works. The results are discussed in relation to the spatial requirements of both species and the protection of utilised habitat features. Management options are suggested to mitigate the impacts of road works. Differences in spatial dynamics of both frogs with overlapping habitats highlighted in this study require species-specific management approaches.

Habitat requirements and habitat use for Pseudophryne australis and Heleioporus australiacus were investigated to aid management of these threatened frogs around Sydney, Australia. Much of the work focussed on roads, commonly encountered features in the habitat of both species. The habitat requirements based on locality records of both frogs in the Sydney Basin were investigated at four spatial scales. Both species are habitat specialists. They showed a strong geological association with Hawkesbury Sandstone and occupy upper topographic areas with ephemeral watercourses of gentle gradients. Both frogs occur predominantly in areas of higher precipitation and milder temperature regimes compared to averages representative of the region. Leaf litter is an important feature of P. australis breeding sites, whereas H australiacus generally associate with crayfish burrows. Both species are dependent on natural vegetation with a complex structure. H australiacus have a relatively long larval period (3 - 12 months) and breed in ephemeral pools, exposing their tadpoles to the risk of dying due to early pond drying. In the laboratory, tadpoles responded to decreasing water levels by shortening their larval periods and metamorphosing earlier than siblings held at constant water level. Despite this plastic response, a number of pools in the field failed to produce metamorphs due to early drying, an observation also made on P. australis. Regular monitoring of breeding sites revealed increased reproductive success away from roads for both species probably because of relatively longer hydroperiods. Spatial distributions and associations with habitat features, and movement patterns of both frogs were further investigated using mark-recapture methods. Both species showed strong site fidelity. P. australis formed small aggregations and predominantly selected leaf litter piles despite their relatively low availability. Leaf litter piles in creeks moved over time and the animals moved with these piles. In contrast, H australiacus individuals formed no aggregations and showed no preference for any available structural vegetation type. Locations of individuals were independent of relative distances to creeks and artificial drains, but males appeared to be more common near culverts. However, individuals were randomly distributed in space and nearest-neighbour distances were high relative to individual movement distances, suggesting minimal overlap between relatively large home ranges. Radio-telemetry demonstrated that some H australiacus individuals burrow in the road environment. There they would be at risk of being dug up and possibly injured during road works. The results are discussed in relation to the spatial requirements of both species and the protection of utilised habitat features. Management options are suggested to mitigate the impacts of road works. Differences in spatial dynamics of both frogs with overlapping habitats highlighted in this study require species-specific management approaches.

Thesis (M.S.)--University of Missouri-Columbia, 2005. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (January 10, 2007) Includes bibliographical references.

Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 25, 2007) Vita. Includes bibliographical references.

Despite an enormous amount of information on the biochemical and physiological changes of amphibian metamorphosis, information about the general anatomy of anuran larvae is not readily available. The present study is a comparison of the general morphological changes during metamorphic climax of three anuran species belonging to three different families. This anatomical information is designed to assist those wishing to correlate cellular and chemical events with the corresponding morphological events.

The endangered Western Leopard Toad (Amietophrynus pantherinus) is endemic to the winter-rainfall parts of the Western Cape, areas which are also favoured for human settlement. Residents in the Noordhoek area witnessed many toads being killed on roads during their annual migration to breeding ponds. Concerned citizens mobilised a volunteer group to mitigate this threat to the species. Toad NUTS (Noordhoek Unpaid Toad Savers), a well-established and successful citizen science group is explored as a case study of how environmental citizenship emerges in a citizen science group. This research has three research goals. Firstly to probe the enabling and constraining factors shaping the Toad NUTS practices, secondly to investigate the learning dynamics in the citizen science group and thirdly to understand how participation in citizen science develops environmental citizenship. Practice architectures theory (Kemmis & Grootenboer, 2008) was used to explore how cultural-discursive, economic-material and social-political arrangements shape the practices of the Toad NUTS group. The Toad NUTS group was identified as a community of practice, therefore Lave and Wenger’s (1991) communities of practice theory was used to better understand the social learning processes within the group. The Global Citizenship Education international policy document was used to capture the aims of citizenship education as it relates to environmental issues and identifies the competencies that citizenship education initiatives should develop. The practices of the Toad NUTS group were investigated for evidence of the goals and competencies identified in the Global Citizenship Education policy documents of environmental citizenship. Data was generated through documentary research, surveys, a questionnaire, semi-structured interviews and observations. The data was stored, organised and analysed using NVivo data management software in three phases corresponding to the three research goals. With respect to Goal 1, the evidence suggested that there are various shaping arrangements of cultural-discursive, material-economic and social-political configurations which influence Toad NUTS practices. Volunteers must learn to navigate these arrangements in order to successfully implement conservation strategies. The shaping features identified were the WhatsApp group communication system used by volunteers; public awareness and education strategies; equipment, material and funding required for implementing the group’s practices; power balances and exchanges between stakeholders in the conservation field; bureaucratic processes and scientist-lay person exchanges. Very important for facilitating social-political connections to various stakeholders, is the membership Toad NUTS enjoys on the Western Leopard Toad Conservation Committee. With respect to Goal 2, four interconnected components of learning were investigated. These were: learning as belonging, learning as doing, learning as meaning-making experience and learning as becoming. Members learn by doing things together like training, patrolling and deliberating problems in the field. They learn by exploring what is collectively known from past and unfolding experiences. Evidence showed that learning deepens as Toad NUTS members perceive their praxis as meaningful and their identities evolve as their knowledge and experience grows. This strengthens members’ sense of belonging and identification with the Toad NUTS group. In time the group develops a reputation and the wider community acknowledges the expertise and knowledge that resides with the group. With respect to Goal 3, it was found that volunteers who have a predisposition for environmental citizenship are more likely to join a citizen science group. Although volunteers care about nature and want to make a difference, it is after gaining access to the embedded knowledge and knowledge processes of the citizen science group that they realise meaningful sustainable solutions to the issue(s) that the project is concerned with. It was found that knowledge paired with reasoned practice enables the agency of volunteers to bring about positive and meaningful change in the local environment. If facilitated carefully, citizen science can make positive contributions to the field, in this instance, conservation, while allowing volunteers to exercise environmental citizenship engaging in participative governance with regard to the project.

Tests of optimal foraging theory have shown that many predators are selective about which prey and which patches should be utilized. I hypothesize that prey species "exploit" this choosiness by evolving characteristics that cause predators to choose alternate prey. Specifically, prey should evolve traits that increase the probability of predator death, decrease the per prey or per patch nutritional intake, increase processing time, and advertise (or mimic advertisements of) undesirable traits. Predator choosiness allows prey to divert the predator instead of defeating it. The evolution of a long-term, prudent foraging strategy requires that three conditions be met: (1) The forager must use resources from a discrete subpopulation; (2) use of that subpopulation must be relatively exclusive; (3) the resource population must respond in such a way that a long-term strategy provides an economic advantage. For the horned lizard-ant system, conditions (1) and (2) were tested by tagging lizards with transmitters or radioactive tags. Horned lizards occupy home ranges much smaller than would be expected if they moved at random and home range overlap was less than expected by random placement of home ranges, thus conditions (1) and (2) were not rejected. Most techniques of home range study do not distinguish random from nonrandom movement. Condition (3) was tested by subjecting ant colonies to various levels of artificial predation. In none of five experiments was the result obtained that an increased harvest intensity led to a decrease in long-term yield; condition (3) is tentatively rejected. Ant colonies shut down in response to predation; this puts a ceiling on their losses. Short-term foraging models were tested for horned lizards foraging at ant colonies. A prediction of the marginal value theorem was not rejected: Horned lizards tended to leave colonies when their instantaneous rate of harvest at that colony had fallen to their average rate of harvest for the day. Another short-term prediction, however, was rejected: Lizards did not stay longer at the "better" of two colonies. A more liberal version of the same prediction was not rejected. Apparently, horned lizards forage adaptively but not optimally.

This study was the first research endeavor ever conducted concerning the population of Western toads, Anaxyrus boreas, at the Bernard Field Station. Despite the current lack of information regarding this population, they will become a concern in future years because they are threatened by habitat destruction. Preceding this study, a single breeding pond has been available to this population, which has been in use for the past 20 to 30 years. However, it is likely that the current breeding pond will be destroyed and the will be land developed for human use. In order to provide these toads with another breeding site, a new pond was constructed. Its suitability as an aquatic habitat was assessed on the basis of temperature, light intensity, algal growth and sediment levels in comparison to conditions at the old breeding pond. When tadpoles were raised in the laboratory in various water treatments, those reared in water from the new pond showed no decrease in survivorship or growth rate. The only significant difference in growth was between laboratory-raised and field animals. Tadpoles living in the field were both smaller in length during the larval period as well as smaller in mass at metamorphosis. Additionally, 75% of the tadpoles translocated to the new site completed full metamorphosis. Therefore, the new pond is both hospitable and conducive to tadpole development, a positive sign for future conservation efforts.

In response to imminent habitat destruction at the Robert J. Bernard Biological Field Station (BFS), translocation was assessed as a conservation strategy for a population of Western toads (Anaxyrus boreas). Currently, the BFS is home to a relatively unstudied population of Western toads, which rely on the existence of a seasonal breeding pond in open land owned by Harvey Mudd College on the west side of the field station. Unfortunately, there are plans to develop this plot of land within the next few years and so the breeding pond will be destroyed. In an effort to protect the Western toads, which are listed as Near Threatened by the International Union for Conservation of Nature and Natural Resources (IUCN) Red List of Threatened Species, a new breeding pond was developed within the protected portion of the field station. Then, the potential of the new pond to be used as a habitat for Western toads was assessed. Pond temperatures, light intensities, algae growth, and suspended material were measured in both the original and the new ponds from January to April, 2010 and were found to be suitable in both locations for the development of Western toad tadpoles. When eggs were laid in the original breeding pond, egg and then later tadpole development were monitored in the field. Additionally, nearly 400 tadpoles were captured and raised in the laboratory in water from both the new and old ponds (as well as dechloraminated tap water) in order to determine how and to what degree the different pond water types affected the development and survival of the tadpoles. In the laboratory, tadpole survival and the percent of tadpoles to achieve full metamorphosis was higher in water from the new pond than water from the original breeding pond, suggesting that there is nothing apparent about the water chemistry in the new pond that would limit tadpole development. Lastly, a mini-translocation of 400 young tadpoles was completed as a trial for a full-scale relocation attempt in the future. These tadpoles developed normally in the new pond when compared to tadpoles from the original pond and also had a high survival rate (at least 75%) to full metamorphosis. Translocation success cannot be determined without long-term monitoring and unfortunately, although the aquatic habitat of the new pond seems suitable for relocation, the terrestrial habitat as well as the predator density surrounding the new pond may limit its success in the future. However, due to the lack of time before the original breeding pond is destroyed, full-scale translocation of eggs and tadpoles during the next breeding season is recommended.