<i>Pteropus rufus,</i> Madagascar's largest endemic fruit bat, is widely distributed but declining in number due to habitat loss and over-hunting. The roost of Berenty, located in a 250 ha remnant of gallery forest surrounded by 30,000 ha of sisal plantations and patches of endemic spiny forest, is the largest in southeastern Madagascar and is an important historical breeding site for this species. Compared with conspecifics elsewhere in Madagascar the diet of <i>P. rufus</i> at Berenty is narrow, containing only 17 plant species. Seven gallery forest and four cultivated species are consistently utilised by the bats, but no endemic spiny forest species were identified in their diet. Pollen of <i>Agave sisalana</i>, present in 84% of faecal samples, contains 36% protein, the main digestive extraction of which was high (73%). Native fruits provide more protein that cultivars, but the latter have significantly higher concentrations of soluble carbohydrates. <i>P. rufus</i> has high mean buccal extraction for nitrogen (73%); carbohydrates (86%); condensed tannins (46%) and phenolics (24%). However, contrary to expectation condensed tannin extraction had no significant effect on nitrogen extraction. <i>P. rufus</i> swallows more viable than non-viable <i>Ficus</i> seeds. In 92% and 58% of germination trials, bat-passed seeds had the highest percentage germination and fastest rate of germination, respectively, compared with seeds from ripe fruits, ejecta pellets or faeces of other frugivores. A minimum foraging range of 17 km was established. The role of <i>P. rufus</i> in pollination is inferred from the presence of pollen on the head and thorax of bats and in their faeces. <i>P. rufus </i>is therefore, an important seed disperser and potentially important pollinator. However, at Berenty its' heavy reliance on the introduced cultivator <i>A. sisalana,</i> unique among the Pteropodidae, suggests that without this resource the remaining gallery forest could not support such a large colony of <i>P. rufus.</i>

Thesis (Ph.D.) - University of Queensland, 2005. / Includes bibliography.

Thesis (M.Phil) - University of Queensland, 2005. / Includes bibliography.

Abstract Pteropid bats are species of zoonotic significance and are known to be reservoir hosts of many viral diseases recently emerged in Asia and Australia. The transfer of these organisms from bats into terrestrial hosts resulted in lethal illnesses in humans and animals. Implementing attentive strategies for the detection and monitoring of these organisms is essential to the protection of humans, animals and the balance of the global economy. Unfortunately the paucity of information on these mammals’ immune system and the absence of diagnostic tools for the detection and for the studying of the humoral response in these animals disengage us from responding promptly when such outbreaks occur and prevent us from describing the possible underling causes that may be responsible for the absence of symptoms in bats infected with such organisms. It was assumed that flying foxes have immunoglobulin like molecules that provide humoral response and are involved in mediating secondary effector functions such as complement fixation and activation of other components of the cellular response in a similar manner as it occurs in humans and other mammals. The aims of this study which include immunoglobulin isotype identification, purification and characterisation as well as generation of reagents that are immunoglobulin class specific, provide the primary platform that should enable us to begin examining these questions. IgG was purified from the black flying fox’s serum by affinity chromatography using Protein G and Protein A. Protein L was ineffective in purifying any antibody from the bat serum. The heavy chain of IgG was also purified by gel electroelution. IgG was digested with papain to yield Fab and Fc fragments. The identity of the bat IgG was confirmed by N-terminal sequencing of the heavy chain and light chain of immunoglobulins separated by SDS-PAGE and by N-terminal sequencing of Fc and Fc' fragments. IgM has also been purified using methods that have not been previously explored to our knowledge. These methods consisted of the purification of Fab specific antibodies from antisera generated against Fab, and using these antibodies to capture other immunoglobulin classes in samples that had been previously enriched by classical fractionation methods. Antisera against the whole IgG molecule, Fc, Fab, IgG heavy chain and IgM heavy chain have been produced in rabbits and tested by Western blot and ELISA. The antisera against the whole IgG molecule and against the Fc were also utilized to detect antibodies to Nipah virus in bats that were found positive to Serum Neutralisation Test. Failure to identify the bat IgA in the bat serum poses questions on the presence, abundance and functional significance of such molecule in bats. The tools that were generated in this study recognise immunoglobulin isotypes, which enabled us to detect and measure antibodies and will allow the study of the humoral response in infected bats to a large extent. Tedious approaches routinely adopted for the purification of antibodies involve a series of pre-fractionation steps or affinity chromatography which rely on the use of expensive immobilised novel or partially characterised ligands, with no guarantee of affinity for the immunoglobulin isotype of interest. The method adopted for immunoglubulin isotype purification described in this study proved to be an effective, reasonably quick and economic solution for immunoglubulin isotype purification from any mammalian species.

Throughout their world distribution, fruit bats (Chiroptera: Pteropodidae) play an extremely important role in forest ecology through seed dispersal and pollination. However, the recognition of their role in maintaining forest ecological diversity has been largely overshadowed by the fact that fruit bats are known to cause damage to a wide variety of cultivated fruits and, as a result, significant effort is undertaken to control fruit bat numbers in areas where crop damage frequently occurs. In Australia, fruit bats of the genus Pteropus (or flying foxes) are well known for their role in destroying valuable fruit crops, particularly along the east coast from Cairns to Sydney. Historical evidence suggests that flying foxes have been culled as an orchard pest in large numbers for the past 80 years. Uncontrolled culling both on-farm and in roosts coupled with extensive habitat destruction in the past century, has resulted in noticeable declines both in flying fox distribution and local population numbers. In New South Wales, flying foxes have been 'protected' under the National Parks and Wildlife Act (1974) since 1986. From that time, fruitgrowers have been required to obtain a licence (referred to as an occupier's licence) from the National Parks and Wildlife Service (NPWS) to cull flying foxes causing damage to fruit crops. However, despite the 'protected' status of the species, flying foxes continue to be culled in large numbers as an orchard pest. An examination of the management of flying foxes in NSW, has shown that, between 1986-1992, fifteen NSW National Parks and Wildlife Service Districts issued a combined total of 616 occupier's licences to shoot flying foxes with an total allocation of over 240,000 animals. In addition, most flying foxes are culled when the female is carrying her young under wing or when the young remain in the camp but continue to be dependent on her return for survival. Further evidence on the extent of culling includes a widely distributed fruitgrower survey with responses indicating that as few as 50% of the fruitgrowers shooting flying foxes in NSW obtain the required licence from the National Parks and Wildlife Service. While the NPWS has undertaken research into the role of flying foxes in seed dispersal and pollination, management effort largely continues to focus on resolving conflicts between fruitgrowers and flying foxes primarily by issuing culling permits to fruitgrowers. At present, there is no NPWS policy on the management of flying foxes in NSW to guide the administration of the permit system. As a result, the process of issuing permits for flying foxes is largely inconsistent between NPWS Districts. The absence of comprehensive goals and objectives for the management of flying foxes has resulted in the current situation where large numbers of flying foxes are being culled both legally and illegally in the absence of any data on the impacts of unknown culling levels on local flying fox populations. The NPWS has a statutory obligation to manage flying foxes consistent with the 'protected' status of the species in NSW and several well known principles of wildlife management. However, current management of flying foxes in indicates that the Service may be in violation of the requirement to 'protect' and 'conserve' flying foxes as required under the National Parks and Wildlife Act (1974). This study recommends that licences issued to fruitgrowers to cull flying foxes be discontinued immediately and that adequate enforcement be engaged to reduce illegal shooting. This action should continue until such time that research on flying fox populations is able to demonstrate that the culling of flying foxes will not lead populations into decline. Furthermore, management effort should focus on the development of alternative strategies to reduce crop damage by flying foxes and provide incentives for growers to utilize existing control strategies such as netting.

Thesis (Ph. D.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references (leaves 134-149).

Thesis (Ph. D.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references (leaves 134-149). / Also available by subscription via World Wide Web / vi, 149 leaves, bound ill. (some col.), col. map 29 cm