The Diet of the Sooty Owl Tyto tenebricosa in the Blue Mountains, N.S.W (original) (raw)
Related papers
Ecology and conservation of owls, 2002
Fragmentation of native forest and woodland by clearing for agriculture and urban development has had a greater effect than logging on large forest owls and their arboreal marsupial prey. In this study, assessments were made of the contribution of forest and woodland fragments on privately-owned and unprotected lands towards the regional conservation of these species in southeastern New South Wales. Small (<200 ha) frag- ments did not provide a significant reservoir for populations of the Powerful Owl Ninox strenua, Sooty Owl Tyto tenebricosa and Masked Owl T. novaehollandiae. Virtually all records of these owls in the region were associated with extensively forested areas or occurred within one km of the boundary of these areas (mainly state forests, national parks and nature reserves). The Barking Owl N. connivens, a ‘non-forest’ species, was also rarely recorded in forest/woodland fragments, raising concerns about the conservation status of this species in the region. Several important prey species for the three large forest owls, in particular the Common Ringtail Possum Pseudocheirus peregrinus, Greater Glider Petauroides volans and the Sugar Glider Petaurus breviceps, were either absent or less abundant in small forest fragments. The Barn Owl Tyto alba, a woodland species, and two other nocturnal ‘forest’ birds, the Southern Boobook Ninox novaeseelandiae and Australian Owlet-nightjar Aegotheles cristatus, were common and widespread in small forest and woodland fragments.
Barking Owl Diet in the Pilliga Forests of Northern NSW
2011
"The Barking Owl Ninox connivens population in the Pilliga forests of northern New South Wales is the largest known in southern Australia. Breeding pairs in this population occupy large home-ranges across less than half of the forest. In this thesis, I quantify the diet of Barking Owls in the Pilliga. I consider a number of hypotheses that could explain the species’ large home ranges and restricted distribution, particularly those that are related to prey availability. This is the first diet study of a Barking Owl population to incorporate data from many territories over several years and all seasons of the year. Radio-tracking of nine owls provided the opportunity to begin a substantial collection of prey remains (regurgitated pellets, food debris and faecal material). Ultimately, the collection period spanned 2003 – 2009, with prey remains from 19 territories in the Pilliga and one territory in a small forest to the south near Dubbo. In total, 1546 regurgitated pellets and 315 faecal samples were collected and examined. Foraging observations improved the understanding of the results. Barking Owls in the Pilliga forests preyed on most species of diurnal and nocturnal birds, as well as Sugar Gliders, bats and insects, with a few items being taken from the ground. Prey size ranged from 0.3 gram insects to ~800 gram cockatoos and mammals, a similar size to the owls. Most prey were native animals in contrast to some other studies. The proportions of consumed prey, as determined by pellet analysis, were compared with available prey, as determined by bird counts, spotlight surveys, small mammal trapping, bat surveys and insect netting. Prey items from all prey groups were available from all sampled areas of the Pilliga. Barking Owls distribution was positively associated with prey availability: significantly with the biomass of birds and with flying insect numbers. Mammal groups were not significantly different but showed the same positive trend. Spatial availability of total prey biomass offered a good explanation for the distribution of Barking Owls within the Pilliga forests. Crucial food resources, particularly available biomass of diurnal birds and nocturnally active prey, may limit the population density and distribution of owls in what appears to be marginal rather than prime habitat. Land cleared for agriculture, because of its higher productivity, may have previously supported higher densities of Barking Owls when wooded."
Further Dietary Items of the Eastern Barn Owl Tyto javanica in Diamantina National Park, Queensland
Summary. The diet of the eastern Barn Owl Tyto javanica was determined by analysis of 46 pellets from a roost in diamantina National Park, Queensland, collected in June 2007. The diet comprised 43% mammals (31% dasyurids, 12% rodents), 8% birds, 1% lizards and 48% insects, by number; and 72% mammals (44% dasyurids, 28% rodents), 22% birds, 1% lizards and 5% insects, by biomass. Mammals occurred in 39 pellets (85%), birds in nine (20%), lizards in two (4%) and insects in 21 (46%). Among many other dietary studies of the eastern Barn Owl Tyto javanica in Australia, particularly the arid zone, there have been three previous pellet samples analysed from diamantina National Park in arid western Queensland (debus et al. 1999, 2007; Palmer 2001). The earlier samples contained mainly rodents, leading Palmer (2001) to suggest that the Owl is a rodent specialist, even in the arid zone, and therefore unlikely to take small marsupials in sufficient quantities to enable its pellets to be used to...
Conservation and management of large forest owls in southeastern Australia
The Powerful Owl (Ninox strenua), Sooty Owl (Tyto tenebricosa) and Masked Owl (Tyto novaehollandiae) are widespread, naturally uncommon species whose conservation requirements are unlikely to be met wholly within a system of formal nature conservation reserves. Until recently, little was known about the distribution, abundance and habitat requirements of these owls, and the extent to which wood production forestry may be compatible with their conservation. The Powerful Owl and Sooty Owl were recorded commonly in logged landscapes but the home ranges for these birds were centred upon significant areas of unlogged or less disturbed forest in riparian areas. The Masked Owl appeared to have a closer associatoin with unlogged or selectively-logged forests, particularly those having an open understorey and sparse ground cover. The management procedures in place for these large forest owls in wood production forests in southeastern Australia are reviewed.
Conserving owls in Sydney’s urban bushland: current status and requirements
The distribution of records for the seven species of owls that have been recorded in the Sydney region are presented. Records made during the past decade have been compared, where possible, with records made since the beginning of the twentieth century. Information is also presented on aspects of the ecology (diet, habitat, nest sites, roost sites, breeding success) of these species in the Sydney region. The Powerful Owl is widely distributed, albeit at very low population density, throughout the outer suburbs of the greater metropolitan area, particularly where these suburbs adjoin substantial areas of bushland and reserves. The Sooty Owl and the Masked Owl are restricted to a few such locations near Sydney, but both are more common in the wetter and the drier forests, respectively, of the Central Coast. The Barking Owl appears to be uncommon and of concern because this species is poorly conserved in national parks of the region and its habitat is threatened by continued clearing for agriculture and urban developments. The Grass Owl appears to be a rare vagrant to the Sydney region. The Southern Boobook and the Barn Owl may be common in the region, but their distribution and abundance appears to have been under-represented by official records. The status of all owls is imperfectly known within the most suburban parts of the Sydney metropolitan area and on surrounding semi-rural properties. Efforts are needed to encourage broadscale community participation in voluntary surveys for owls (and several of their main prey species) throughout residential areas. The conservation of owls in the Sydney region depends on the protection of extensive bushland areas from urban and rural development, especially the major forested gully systems which provide essential nesting, roosting and core foraging habitat for most species. The role of fire frequency and weed control in Sydney’s urban bushland needs to be examined in terms of its impact on populations of the Common Ringtail Possum, and other important prey species of the owls.