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.

Northern environments are often characterised by large seasonal and annual fluctuations in food abundance. In this thesis, I examined how arctic foxes (</i>Alopex lagopus</i>) used seasonally superabundant foods (geese and their eggs) and how access to these foods influenced population dynamics of arctic foxes. I addressed this against a backdrop of variation in lemming and vole abundance (small mammals hereafter) the main foods of arctic foxes throughout most of their range. Field work was done at the large goose colony at Karrak Lake and surrounding areas in the Queen Maud Gulf Bird Sanctuary in Nunavut, Canada, in the spring and summers of 2000 to 2004. <p> Behavioural observations of individually-marked arctic foxes showed that they took and cached 2,000-3,000 eggs per fox each year and that the rate at which they took eggs was largely unrelated to individual attributes of foxes (e.g. sex, size, and breeding status) and nesting distribution of geese. Further, the rate at which foxes took eggs varied considerably within individuals in that foxes were efficient at taking eggs at times and inefficient at other times. This may have resulted from foxes switching between foraging actively and taking eggs opportunistically while performing other demands such as territorial behaviours. <p>Comparison of stable isotope ratios (13C and 15N) of fox tissues and those of their foods showed that the contribution of cached eggs to arctic fox diets was inversely related to collared lemming (<i>Dicrostonyx torquatus</i>) abundance. In fact, the contribution of cached eggs to overall fox diets increased from <28% in years when collared lemmings were abundant to 30-74% in years when collared lemmings were scarce. Furthermore, arctic foxes used cached eggs well into the following spring (almost 1 year after eggs were acquired) a pattern which differs from that of carnivores generally storing foods for only a few days before consumption. <p>A field-study of experimental caches showed that survival rate of these caches was related to age of cache sites in the first year of the study (e.g. 0.80 and 0.56 per 18-day period for caches from new and 1 month old cache sites, respectively) and departure by geese after hatch in the second year of the study (e.g. 0.98 and 0.74 per 18-day period during and after goose nesting, respectively). Food abundance and deterioration of cache sites (e.g. loss of soil cover and partial exposure of caches) were, thus, important factors affecting cache loss at Karrak Lake. Further, annual variation in the importance of these factors suggests that strategies to prevent cache loss are not fixed in time but vary with existing conditions. Evolution of caching behaviours by arctic foxes may, thus, have been shaped by multiple selective pressures. <p>Comparisons of reproductive output and abundance of arctic foxes inside and outside the goose colony at Karrak Lake showed that (i) breeding density and fox abundance were 2-3 times higher inside the colony than they were outside the colony and (ii) litter size, breeding density, and annual variation in fox abundance followed that of small mammal abundance. Small mammal abundance was, thus, the main governor of population dynamics of arctic foxes whereas geese and their eggs elevated fox abundance and breeding density above that which small mammals could support. These results highlight both the influence of seasonal and annual variation on population dynamics of consumers and the linkage between arctic environments and wintering areas by geese thousands of kilometres to the south.

Northern environments are often characterised by large seasonal and annual fluctuations in food abundance. In this thesis, I examined how arctic foxes (</i>Alopex lagopus</i>) used seasonally superabundant foods (geese and their eggs) and how access to these foods influenced population dynamics of arctic foxes. I addressed this against a backdrop of variation in lemming and vole abundance (small mammals hereafter) the main foods of arctic foxes throughout most of their range. Field work was done at the large goose colony at Karrak Lake and surrounding areas in the Queen Maud Gulf Bird Sanctuary in Nunavut, Canada, in the spring and summers of 2000 to 2004. <p> Behavioural observations of individually-marked arctic foxes showed that they took and cached 2,000-3,000 eggs per fox each year and that the rate at which they took eggs was largely unrelated to individual attributes of foxes (e.g. sex, size, and breeding status) and nesting distribution of geese. Further, the rate at which foxes took eggs varied considerably within individuals in that foxes were efficient at taking eggs at times and inefficient at other times. This may have resulted from foxes switching between foraging actively and taking eggs opportunistically while performing other demands such as territorial behaviours. <p>Comparison of stable isotope ratios (13C and 15N) of fox tissues and those of their foods showed that the contribution of cached eggs to arctic fox diets was inversely related to collared lemming (<i>Dicrostonyx torquatus</i>) abundance. In fact, the contribution of cached eggs to overall fox diets increased from <28% in years when collared lemmings were abundant to 30-74% in years when collared lemmings were scarce. Furthermore, arctic foxes used cached eggs well into the following spring (almost 1 year after eggs were acquired) a pattern which differs from that of carnivores generally storing foods for only a few days before consumption. <p>A field-study of experimental caches showed that survival rate of these caches was related to age of cache sites in the first year of the study (e.g. 0.80 and 0.56 per 18-day period for caches from new and 1 month old cache sites, respectively) and departure by geese after hatch in the second year of the study (e.g. 0.98 and 0.74 per 18-day period during and after goose nesting, respectively). Food abundance and deterioration of cache sites (e.g. loss of soil cover and partial exposure of caches) were, thus, important factors affecting cache loss at Karrak Lake. Further, annual variation in the importance of these factors suggests that strategies to prevent cache loss are not fixed in time but vary with existing conditions. Evolution of caching behaviours by arctic foxes may, thus, have been shaped by multiple selective pressures. <p>Comparisons of reproductive output and abundance of arctic foxes inside and outside the goose colony at Karrak Lake showed that (i) breeding density and fox abundance were 2-3 times higher inside the colony than they were outside the colony and (ii) litter size, breeding density, and annual variation in fox abundance followed that of small mammal abundance. Small mammal abundance was, thus, the main governor of population dynamics of arctic foxes whereas geese and their eggs elevated fox abundance and breeding density above that which small mammals could support. These results highlight both the influence of seasonal and annual variation on population dynamics of consumers and the linkage between arctic environments and wintering areas by geese thousands of kilometres to the south.

Magistro darbe tiriama plėšriųjų žvėrių ir tetervinų populiacijos būklė. Tyrimo objektas – Radviliškio rajone esančiame Praviršulio tyrelio valstybinio botaninio - zoologinio draustinyje sutinkami plėšrieji žvėrys ir tetervinai. Darbo tikslas - nustatyti plėšriųjų žvėrių ir tetervinų populiacijos būklę Praviršulio tyrelio valstybiniame botaniniame – zoologiniame draustinyje. Siekiant darbo tikslo buvo iškelti tokie uždaviniai: 1) ištirti draustinio plėšriųjų žvėrių rūšinę sudėtį, atskirų rūšių gausą bei tankį; 2) apskaičiuoti tetervinų gausą bei tankį; 3) apskaičiuoti plėšrūnų ir aukų santykį bei jo atitikimą ekologiniam santykiui; 4) ištirti plėšriųjų žvėrių ir tetervinų populiacijos dinamiką. Tyrimo metodai - Lietuvos ir užsienio autorių mokslinės literatūros analizė bei sintezė, duomenų grupavimas, statistiniai metodai, grafinis vaizdavimas. Tyrimo laikotarpis apima 2008 -2009 metus. Darbo rezultatai: buvo išstudijuota lietuvių ir užsienio autorių moksliniais darbai bei periodinė literatūra apie medžiojamosios faunos elgseną įtakojančius veiksnius, buvo ištirta draustinio plėšriųjų žvėrių rūšinė sudėtis, apskaičiuota žvėrių gausa, bendras tankis, ištirta žvėrių populiacijos dinamika. Gauti tokie rezultatai: 2008-2009 metais plėšriųjų žvėrių gausa didėjo. Apskaičiuoti plėšriųjų žvėrių ir aukų santykiai gana labai neatitiko ekologinių. Tetervinų gausa 2008-2009 metais sumažėjo. / Master's work examined prey animals, and heath-cock population of the state. Object of research – Carnivora and heath-cocks met in the territory of Praviršulis tyrelis public botanical - zoological reservation in Radviliškis district. Purpose of the Paper – estimate the state of Carnivora and heath-cocks in the Praviršulis tyrelis public botanical - zoological reservation. Achieving the purpose the following goals were raised: 1) to determine the varietal composition, abundance and density of certain species of the Carnivora in the reservation; 2) to determine the abundance and density of heath-cocks in the reservation. 3) to determine the ratio between predators and preys, and its conformity with ecological ratio; 4) to explore the dynamics of Carnivora and the heath-cock populations. Methods of research - analysis and synthesis of Lithuanian and foreign scientific literature, data grouping, statistical methods, graphical presentation. The research period is the years 2008 - 2009. The results: there was studying scientific works of Lithuanian and foreign authors and periodic literature about the factors influencing the behaviours of fair game, there was determined the abundance of animals, general density, determined the dynamics of animals population. Obtain the following results: 2008-2009, increased the abundance of prey animals. Calculate prey animals and the relationship between the victims is quite inconsistent with the ecological. Hheath-cocks abundance declined in 20... [to full text]

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2004. / Härtill 5 uppsatser.

Thesis (Ph.D.)--University of Wollongong, 2005. / Typescript. Includes bibliographical references.

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

Thesis (doctoral)--Uppsala universitet, 1983. / Summary in English. Includes bibliographical references (p. 110-119).

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2010. / Härtill 5 uppsatser.

Thesis (troisième cycle)--Université de Paris III, 1983. / Bibliography: p. 212-219.