10 results on '"S J S Debus"'
Search Results
2. Diet of the Australian Hobby Falco longipennis breeding in Canberra, Australian Capital Territory, in 2002–2004 and 2005–2008
- Author
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Jerry Olsen, S J S Debus, David Judge, and Susan Trost
- Subjects
Accipiter cirrocephalus ,Sturnus ,biology ,Habitat ,Australian hobby ,Foraging ,Zoology ,biology.organism_classification ,Hobby ,Sparrowhawk ,Predation - Abstract
The diet of the Australian Hobby Falco longipennis was studied in Canberra (ACT), in the summers of 2002–2003 to 2004–2005 and 2005–2006 to 2008–2009 by analysis of prey remains and pellets (28 and 40 collections for a total of 229 and 132 prey items from six and four nests, respectively). The Hobbies’ breeding diet in the first period consisted of 73% birds, 1% microbats and 26% insects by number, and 98% birds
- Published
- 2020
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3. Inheritance of plumage morphs in Little Eagles Hieraaetus morphnoides in northern New South Wales
- Author
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Candice Larkin and S J S Debus
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genetic structures ,biology ,Offspring ,Inheritance (genetic algorithm) ,Zoology ,Little eagle ,biology.organism_classification ,symbols.namesake ,Plumage ,Mendelian inheritance ,symbols ,sense organs ,Hieraaetus ,Allele ,Booted eagle - Abstract
Polymorphism and inheritance of plumage colour in the Little Eagle Hieraaetus morphnoides were studied in northern New South Wales, by tallying records of parental morph combinations in breeding pairs and the morphs of their offspring in the 1980s, 2000s and 2017–2019 ( n = 41 pair combinations). The average ratio in breeding adults was 4.9 light:1 dark, with dark males outnumbering dark females (1.8:1). Light × light pairs always produced light young ( n = 32). Dark male × light female pairs variously produced light and dark offspring of both sexes ( n = 12). Light male × dark female pairs produced dark young of either sex ( n = 4) and one light young of unknown sex. One dark × dark pair produced a dark young. We conclude a Mendelian inheritance pattern with the dark morph recessive. From a small sample of mixed pairs with a dark male, the ratio of offspring morphs did not differ significantly from that expected by the Hardy–Weinberg equation, but mixed pairs with a light male produced 4 dark offspring to one light, versus the expected Hard –Weinberg ratio of 1.95 light: 1 dark. This outcome suggests a non-random transmission of the dark allele by heterozygous light males, and a similar pattern of inheritance to that in the related Booted Eagle H. pennatus .
- Published
- 2020
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4. Bird communities in remnant woodland on the upper North-west Slopes of New South Wales
- Author
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Steve Tremont, S J S Debus, and Hugh Ford
- Subjects
Geography ,North west ,Avian diversity ,Ecology ,Threatened species ,Foraging ,Elevation ,Animal Science and Zoology ,Insectivore ,Woodland ,Species richness - Abstract
Bird counts were conducted in woodland remnants of the upper North-west Slopes of New South Wales, an ornithologically little-documented area, in 1995 and 1997. A total of 120 woodland species, including 11 threatened species, was recorded in the area below 900 m elevation, from a point 100 km NNW of Armidale northwards 50 km to the Dumaresq River, thence 50 km north-west across Slopes woodland to the river at Texas (Queensland). Woodland patches ≯300 ha supported significantly more species than those
- Published
- 2006
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5. Changes in woodland bird communities as replanted woodland matures
- Author
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S J S Debus, W. K. Martin, and J. M. Lemon
- Subjects
0106 biological sciences ,Ecology ,biology ,ved/biology ,010604 marine biology & hydrobiology ,ved/biology.organism_classification_rank.species ,Insectivore ,Vegetation ,Woodland ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Shrub ,Geography ,Abundance (ecology) ,Manorina ,Threatened species ,Species richness ,Nature and Landscape Conservation - Abstract
Small patches of woodland were progressively established on degraded agricultural land near Gunnedah, northern New South Wales, on the heavily cleared Liverpool Plains. Birds were resurveyed in the plantings, and in agricultural fields (cropping and pasture) and remnant woodland, in 2011–12, 10 years after initial surveys in 2000–01. The plantings in the later survey were 60, 18, 16 and 13 years old, with a shrub layer included in the three youngest cohorts. The survey sites (total 14 ha planted, all within 200 m of remnant woodland) were paired 1-ha plots in each vegetation category. Birds were surveyed by 30-min area searches of each plot eight times over all seasons, using the same plots, procedure and observer as before. In all, 73 species were recorded in the later survey (versus 72 in the earlier survey), for a total of 87 species over both survey periods, with 58 species in 2011–12 (versus 54 in 2000–01) in the plantings; eight of 15 new species visited or colonised the maturing plantings. Avian species richness and abundance increased from the cleared agricultural plots through the progressively older plantings to resemble those in the remnant woodland. Between the first and second surveys, bird communities in the younger plantings converged with those in the older plantings and woodland. The nectar-feeding, foliage-feeding and ground-feeding insectivore guilds benefitted most, having increased in frequency in, or moved into, the younger cohorts of plantings (>13 years old), or both. Several threatened and other declining woodland birds visited, increased in or colonised the plantings. However, noisy miners (Manorina melanocephala) progressively occupied a few plots and excluded some other birds.
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- 2017
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6. Responses of Eastern Yellow Robins Eopsaltria australis to translocation into vegetation remnants in a fragmented landscape
- Author
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H A Ford and S J S Debus
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Geography ,Ecology ,Habitat ,biology ,Eopsaltria australis ,High mortality ,Woodland ,Vegetation ,biology.organism_classification ,Nature and Landscape Conservation ,Petroicidae ,Predation - Abstract
Many species of Australian robins (Petroicidae) are declining in wooded landscapes across southern Australia, perhaps because they are unable or unwilling to disperse across the matrix between remnants, or because they experience high mortality while doing so. Eastern Yellow Robins Eopsaltria australis have declined in parts of southeastern Australia, and have gone extinct in some woodland remnants. We translocated adult Yellow Robins to remnants from which they had disappeared, and followed their survival and behaviour. Nine Yellow Robins were translocated to a 100 ha remnant in 2001 (seven birds) and 2002 (two birds). One bird disappeared immediately and a second after 2 weeks, but the rest stayed for at least 2 months, with two birds surviving to at least 4 and 5 years. One reintroduced pair bred each year from 2001 to 2005, producing six fledglings. Two colour-banded Yellow Robins also arrived unaided from another remnant 7 km away. Fifteen Yellow Robins were translocated to nine small remnants (
- Published
- 2012
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7. The effect of Noisy Miners on small bush birds: an unofficial cull and its outcome
- Author
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S J S Debus
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Ecology ,biology ,ved/biology ,Native trees ,Noisy miner ,ved/biology.organism_classification_rank.species ,Insectivore ,Woodland ,biology.organism_classification ,Shrub ,Manorina ,Species richness ,Nature and Landscape Conservation - Abstract
This paper documents the bird community in a small (~15 ha) patch of remnant woodland New South Wales sheep? wheat belt (i) before Noisy Miners Manorina melanocephala were abundant in the patch (1972-79), (ii) after a dense miner colony became established (1980-1990), (iii) after the miners were removed (1991?92) and, subsequently, (iv) while extensive, dense plantings of native trees became established (1992-2006). Bird species richness in the patch was, respectively, 64, 18, 45 and 83 species in each time period. Totals for small (
- Published
- 2008
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8. Breeding-habitat and nest-site characteristics of Scarlet Robins and Eastern Yellow Robins near Armidale, New South Wales
- Author
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S J S Debus
- Subjects
Ecology ,biology ,Eopsaltria australis ,ved/biology ,Fledge ,ved/biology.organism_classification_rank.species ,Woodland ,biology.organism_classification ,Shrub ,Predation ,Habitat ,Nest ,Petroica ,Nature and Landscape Conservation - Abstract
I studied the selection of breeding habitat and nest microhabitat in Scarlet Robins Petroica multicolor and Eastern Yellow Robins Eopsaltria australis, in remnant woodland on the New England Tablelands of New South Wales in 2000?2002. Yellow Robins used breeding territories (n = 10) with significantly higher densities of rough-barked saplings, acacias and other (non-Acacia) shrubs than Scarlet Robin breeding territories (n = 10) and plots lacking Yellow Robins (n = 7). Yellow Robins nested mostly in gully and lower-slope positions, with a southerly aspect, >40 m from the woodland edge, whereas Scarlet Robins nested mostly on upper slopes and ridges, with no preferred minimum distance from the woodland edge. Most Yellow Robin nests (86% of 58) had overhead foliage within 1 m, shielding them from above, whereas over half (58% of 54) of Scarlet Robin nests were in unconcealed positions. Yellow Robin nests had significantly greater density of cover, and the surrounding habitat was more complex, than for Scarlet Robin nests, in 0.13-ha plots centred on the nest. Breeding success and fledgling survival in the Yellow Robin were positively related to the density of acacias, non-Acacia shrubs and rough-barked saplings (but not gum saplings) in breeding territories. Fledging success and juvenile survival in the Yellow Robin were also positively related to habitat complexity around nest-sites (but not distance to nearest cover, or items of cover within 20 m). Scarlet Robins had exposed nests and suffered high nest predation, with too few successful nests for comparison with unsuccessful nests. Habitat conservation for the Yellow Robin should address the complexity of the ground, shrub and sapling layer in woodland remnants; that for the Scarlet Robin may need to address foraging substrate and ecologically based control of nest predators.
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- 2006
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9. The role of intense nest predation in the decline of Scarlet Robins and Eastern Yellow Robins in remnant woodland near Armidale, New South Wales
- Author
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S J S Debus
- Subjects
education.field_of_study ,Ecology ,biology ,Eopsaltria australis ,Population ,Fledge ,Woodland ,biology.organism_classification ,Strepera graculina ,Predation ,Nest ,Petroica ,education ,Nature and Landscape Conservation - Abstract
A study of open-nesting Eastern Yellow Robins Eopsaltria australis and Scarlet Robins Petroica multicolor, on the New England Tablelands of New South Wales in 2000?02, found low breeding success typical of eucalypt woodland birds. The role of intense nest predation in the loss of birds from woodland fragments was investigated by means of predator-exclusion cages at robin nests, culling of Pied Currawongs Strepera graculina, and monitoring of fledging and recruitment in the robins. Nest-cages significantly improved nest success (86% vs 20%) and fledging rate (1.6 vs 0.3 fledglings per attempt) for both robin species combined (n = 7 caged, 20 uncaged). For both robin species combined, culling of currawongs produced a twofold difference in nest success (33% vs 14%), a higher fledging rate (0.5 vs 0.3 per attempt), and a five-day difference in mean nest survival (18 vs 13 days) (n = 62 nests), although sample sizes for nests in the cull treatment (n = 18) were small and nest predation continued. Although the robin breeding population had not increased one year after the cull, the pool of Yellow Robin recruits in 2001?03, after enhanced fledging success, produced two emigrants to a patch where Yellow Robins had become extinct. Management to assist the conservation of open-nesting woodland birds should address control of currawongs.
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- 2006
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10. Distribution of Nocturnal Forest Birds and Mammals in North-Eastern New South Wales: Relationships With Environmental Variables and Management History
- Author
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T Tweedie, RP Kavanagh, R Webster, and S J S Debus
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Geography ,Range (biology) ,Ecology ,Vegetation type ,Forest management ,Biodiversity ,Secondary forest ,Species diversity ,Wildlife management ,Understory ,Management, Monitoring, Policy and Law ,Ecology, Evolution, Behavior and Systematics - Abstract
A regional survey of the forests in north-eastern New South Wales recorded eight species of nocturnal forest birds and nine species of arboreal marsupials from 291 sites. Three major environmental gradients accounting for the distribution of these species in north-eastern New South Wales were identified: elevation, forest type (wet forest types having a dense mesic understorey or dry forest types having an open or sparse understorey), and logging intensity. Characteristic assemblages of species were associated with each end of these three gradients. A core group of species occurred across a wide range of environmental conditions, including logged and unlogged forest. Most species occurred with similar frequency in logged and unlogged forest. Implications for forest management are discussed.
- Published
- 1995
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