The diet of a Sooty Owl from Yarrangobilly Caves, NSW

2020 ◽  
Vol 41 (1) ◽  
pp. 139-142
Author(s):  
Rohan J. Bilney

ABSTRACT A total of 783 dietary items from a Sooty Owl Tyto tenebricosa tenebricosa with suspected partial xanthochromism (yellow plumage colouration) was identified from Yarrangobilly Caves, NSW. Observations of the owl at the cave and collection of feathers suggest that prey items accumulated between 2011 and 2018. A total of 12 mammal species was detected in the diet, with the Bush Rat Rattus fuscipes, Agile Antechinus Antechinus agilis, Sugar Glider Petaurus breviceps and Rabbit Oryctolagus cuniculus dominating. The diet also included three threatened species, the Eastern Pygmy Possum Cercartetus nanus, Smoky Mouse Pseudomys fumeus and Broad-toothed Rat Mastacomys fuscus. The diversity of prey identified in the diet contrasts markedly with that found in studies of subfossil deposits from the area, supporting evidence of extensive mammal declines since European settlement.

1998 ◽  
Vol 20 (3) ◽  
pp. 383
Author(s):  
I.G van Tets

Two arboreal marsupials, the eastern pygmy possum (Cercartetus nanus) and the sugar glider (Petaurus breviceps) have exceptionally low maintenance nitrogen requirements on pollen diets. This study compares their nitrogen requirements with the density of Banksia pollen that is available in the Barren Grounds Nature Reserve, New South Wales, a site where both species are known to forage on Banksia inflorescences. The pollen density was sufficiently high that both species were capable of meeting their maintenance nitrogen requirements on pollen whenever Banksia spp. were in flower. C. nanus required a smaller proportion of its home range than P. breviceps to do so and pollen was likely to be of much greater nutritional significance to both species in winter than in summer. This corresponds closely with the results of field studies comparing the diets of these mammals at different times of the year. Pollen is an important source of nitrogen for flower-feeding marsupials but its importance will vary between species depending on the marsupial's requirements, its body size and on the quantity of pollen that is available.


1987 ◽  
Vol 35 (4) ◽  
pp. 319 ◽  
Author(s):  
RL Goldingay ◽  
SM Carthew ◽  
RJ Whelan

Native mammals have been implicated by various authors as visitors to flowers of Australian plants in both eastern and western Australia, but few data are available to allow an estimation of their potential as pollinators. In the present study, Antechinus stuartii, Petaurus breviceps and Rattus fuscipes were regularly trapped in flowering Banksia spinulosa. A few Cercartetus nanus were also captured. Individuals of all species carried pollen on their fur. Pollen loads were greater on mammals which had been in traps for short periods, which suggests that mammals will groom pollen from their fur if left longer in traps. Therefore, pollen loads on foraging mammals have probably been dramatically underestimated by previous authors, and their potential to effect pollination may have been greatly underestimated. Furthermore, significantly more pollen was removed from flowers of B. spinulosa at night than during the day, suggesting the importance of nocturnal pollinators at this site.


2000 ◽  
Vol 27 (1) ◽  
pp. 39 ◽  
Author(s):  
Stephen M. Jackson

Trapping data of the mahogany glider, Petaurus gracilis, and the sugar glider, Petaurus breviceps, in sympatry, in north Queensland, were analysed with vegetation variables to determine the habitat relationships of these two species. The study area contained a trapping grid (80 traps) within an area of continuous forest and trapping transects within an adjacent area of fragmented forest (44 traps). The mahogany glider was trapped more often at 43 of the 124 locations (38 in the continuous and 5 in the fragmented forest), with the sugar glider dominant at 46 locations (18 in the continuous forest and 28 in the fragmented forest). The remaining 27 trap locations where gliders were caught did not favour either species. Eight trap locations within riparian rainforest had no captures of either species. The presence of mahogany gliders was significantly correlated with the presence of Corymbia clarksoniana, Eucalyptus platyphylla, the absence of Corymbia intermedia and Acacia mangium, and a small mid and upper canopy cover. In contrast, the presence of sugar gliders was most correlated with a large number of stems. When the presence of the mahogany glider was compared with that of the sugar glider with respect to various habitat variables for the entire study area, the mahogany glider was most associated with the presence of C. clarksoniana, Eucalyptus pellita, Lophostemon suaveolens, Melaleuca dealbata and a reduced lower and upper canopy. In contrast, the sugar glider was most associated with C. intermedia, A. mangium, a large number of potential food species, rainforest species and a dense mid and upper canopy cover.


1998 ◽  
Vol 20 (1) ◽  
pp. 79
Author(s):  
B.J. Traill ◽  
A. Lill

Populations of the Squirrel Glider, Petaurus norfolcensis and the Sugar Glider, P. breviceps, are often sympatric and the two species are potential competitors for tree hollows. Their use of hollows and artificial nest-boxes was examined in a Box-Ironbark forest where natural hollows are scarce due to past forestry practices. We found gliders used hollows in the boles and branches of trees and in coppicing stumps. There was considerable interspecific overlap in the use of hollows and nest-boxes, both by gliders and other birds and mammals. Both gliders preferred hollows and nest-boxes with narrow entrances (<50 mm diameter). Petaurus breviceps preferred nest-boxes and possibly natural tree hollows with entrances too narrow for the larger P. norfolcensis. When abundant nest-boxes of this type were introduced at the study site, P. breviceps numbers increased and then decreased when the nest-boxes were removed. The results suggest that the larger P. norfolcensis monopolise the best available hollows. Petaurus breviceps numbers may have been limited by a lack of suitable hollows.


1998 ◽  
Vol 4 (4) ◽  
pp. 296 ◽  
Author(s):  
M. C. Calver ◽  
J. Dell

Sixteen mammal species and 22 bird species whose distributions extended into southwestern Australian forests before European settlement have been listed as threatened at some time in Commonwealth legislation, State legislation, or action plans of Environment Australia or its predecessors. Confident assessment of the causes of conservation status is hampered by poor base-line data, few studies of putative impacts and a preponderance of circumstantial or anecdotal rather than experimental evidence. However, introduced foxes were Implicated In the current conservation status of 62% of the mammal species recognized, while 44% of them were negatively impacted by feral cats, 44% by agricultural clearing and 44% by changed fire regimes. Forestry practices were impllcated in the conservation status of only one mammal species. For the bird species recognized, changed fire regimes had the greatest negative impact (45% affected), agricultural clearing affected 41%, draining of wetlands affected 32% and grazing by livestock affected 22%. Forestry practices were not directly implicated in the conservation status of any bird species. While these results suggest that forestry has had minimal direct impact on the mammals and birds of the forests, the conclusion should be treated cautiously because of the poor data. While awaiting a rigorous evaluation, we argue for a strong precautionary approach to forestry in the region. With proper forest management and sound sylvicultural [sic] treatment there is no reason why there should not be built up on the wreckage of the once splendid forests of Western Australia tended forests which will yield for all time 100 cubic feet of timber per acre per year. Lane-Poole (1920). There are many reasons why Australian environmentalists would like to end logging in native forests. The preservation of wilderness, aesthetics, an almost religious identification with old growth forests and the conservation of forest wildlife figure importantly in environmental efforts to restrict logging. Wilderness and a personal identification with trees and undisturbed forests are fundamentally incompatible with logging. Recher (1996).


2006 ◽  
Vol 33 (1) ◽  
pp. 17 ◽  
Author(s):  
Rohan J. Bilney ◽  
Raylene Cooke ◽  
John White

The current diet of the sooty owl (Tyto tenebricosa) was determined by analysing freshly regurgitated pellets collected beneath their roosting sites in East Gippsland, Victoria. Comparisons were then made with: (i) prehistoric and historic diet from bone deposits found in cave roosts, and (ii) diet of a sympatric owl species, the powerful owl (Ninox strenua). Sooty owls consumed a large array of terrestrial mammal species before European settlement, but only three terrestrial species were detected in their current diet, a reduction of at least eight species since European settlement. To compensate, sooty owls have increased their consumption of arboreal prey from 55% to 81% of their diet. Arboreal species are also a major component of the powerful owl diet and this prey shift by sooty owls has increased dietary overlap between these two species. Predation by foxes (Vulpes vulpes) and other feral species is likely to have reduced the amount of terrestrial prey available to sooty owls since European settlement. Investigation of changes in the diet of sooty owls may offer a unique monitoring system for evaluating the ability of fox-control strategies to influence increases in numbers of critical-weight-range mammals.


1987 ◽  
Vol 14 (3) ◽  
pp. 275 ◽  
Author(s):  
D Lunney ◽  
E Ashby

A population of the white-footed dunnart Sminthopsis leucopus was studied from 1981 to 1983 in a forest that had been logged in 1979, burnt in 1980, and was drought-affected throughout the study. S. leucopus bred in this disturbed habitat but did not persist when the vegetation regrew and became dense. Pouch young were present in August, September and October 1981. There was no evidence of polyoestry in the field, although breeding potential may have been suppressed by a combination of the drought and habitat change. There were few brown antechinus Antechinus stuartii present at any time. The population of the bush rat Rattus fuscipes increased as its preferred habitat of dense vegetation grew. An irruption of the house mouse Mus rnusculus in autumn 1982 coincided with a brief respite from the drought. The differing responses of these species to the same set of environmental conditions illustrates that no one management option in such forests will be optimal for all species of small mammals. The conclusion drawn here for the conservation of S. leucopus in forests subject to woodchip logging and fire is to stagger the forestry operations to ensure that not all parts of the forest are covered with dense regrowth at any one time.


2007 ◽  
Vol 13 (3) ◽  
pp. 171 ◽  
Author(s):  
Shannon M. Barber-Meyer

Night light pollution is an important environmental problem impacting on many animals including a variety of insects, amphibians, reptiles, birds, and mammals. While some impacts of night light pollution are well-known such as misorientation of sea turtle hatchlings and deaths of migratory birds, other less obvious impacts on reproduction, communication, competition, and predation have recently been reported. As some natural areas in New Guinea and Australia face agricultural and industrial development, conflicts between wildlife and photopollution will add to existing problems of habitat fragmentation and degradation. I report on the photopollution impacts on the nocturnal behavior of the sugar glider (Petaurus breviceps). Captive sugar gliders were monitored using a "super nightshot" camcorder for baseline nocturnal behaviour following a 12 hour dayligh/12 hour dark regime. Treatment consisted of 12 hour dayligh/12 hour simulated ambient low and high luminosity street light photopollution (average 7.0 and 12.0 lux). Over 575 sugar glider-hours were analyzed. The results show marked behavioural impacts under high luminosity treatment, even 7.0 lux reduced foraging time. This is the first report of photopollution impacts on sugar glider foraging and activity levels. Further research, particularly with wild populations, is needed to elucidate the extent of photopollution impacts on sugar gliders and their endangered and vulnerable relatives.


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