The breeding season diet of wedge-tailed eagles (Aquila audax) in western New South Wales and the influence of Rabbit Calicivirus Disease

2002 ◽  
Vol 29 (2) ◽  
pp. 175 ◽  
Author(s):  
A. Sharp ◽  
L. Gibson ◽  
M. Norton ◽  
B. Ryan ◽  
A. Marks ◽  
...  

A total of 2071 individual prey items were identified from 34 active and 55 inactive wedge-tailed eagle nests following the 1995, 1996 and 1997 breeding seasons. Overall, the eagle's diet was comparable to that reported in other studies within semi-arid regions, with rabbits, reptiles and macropods accounting for 47.8, 22.6 and 13.7% of prey items, respectively. In spring 1996 rabbit calicivirus moved into the study area, resulting in a 44-78% reduction in rabbit abundance (Sharp et al. 2001). An index was developed to enable the time since death for individual prey items to be approximated and a historical perspective of the eagle's diet to be constructed. Rabbits constituted 56-69% of dietary items collected during the pre-rabbit calicivirus disease (RCD) samples, but declined to 31% and 16% in the two post-RCD samples. A reciprocal trend was observed for the proportion of reptiles in the diet, which increased from 8-21% of pre-RCD dietary items to 49-54% after the advent of RCD. Similarly, the proportion of avian prey items was observed to increase in the post-RCD samples. These data suggested that prey switching may have occurred following the RCD epizootic. However, a lack of data on the relative abundances of reptiles and birds prevented an understanding of the eagle's functional responses to be developed and definitive conclusions to be drawn. Nevertheless, the eagles were observed to modify their diet to the change in rabbit densities by consuming larger quantities of native prey species.

2021 ◽  
Vol 38 ◽  
pp. 193-200
Author(s):  
Kimberley Pryor

The breeding diet of a pair of Nankeen Kestrels Falco cenchroides nesting in Beresfield, eastern New South Wales, in 2020 was investigated. By individual prey species, the diet comprised 61.3% reptiles (including two prey species not previously recorded in the Nankeen Kestrel diet—Eastern Water Skink Eulamprus quoyii and most likely Southern Rainbow Skink Carlia tetradactyla), 9.7% birds (including a new prey species—Superb Fairy-wren Malurus cyaneus), 6.4% invertebrates (two crickets: Grylloidea), 3.2% mammals (one House Mouse Mus musculus) and 19.4% unidentified prey items (percentages by number). During 31.5 h of observations, the male delivered 22/31 prey items (71%) and the female delivered 9/31 prey items (29%) to the nest tree. The average delivery rate over the entire nestling period was one prey item per hour. Prey-caching, whereby the female stored lizards in the fork of a tree and later retrieved them and fed them tothe single nestling, was observed. Further studies are needed to obtain well-documented accounts of prey-caching by Australian falcons.


1999 ◽  
Vol 26 (5) ◽  
pp. 593 ◽  
Author(s):  
Robyn Molsher ◽  
Alan Newsome ◽  
Chris Dickman

The diet of feral cats (Felis catus) was studied at Lake Burrendong, central-eastern New South Wales, from July 1994 to June 1997. Mammals were the major prey in 499 scats that were analysed. Rabbits (Oryctolagus cuniculus) were the staple prey, while carrion was an important secondary food. Invertebrates, other mammalian prey, vegetation, birds and reptiles were generally minor components of the diet. Few significant seasonal differences in diet were found; however, invertebrates contributed less and possums more to the diet in winter and summer respectively. A significant dietary response was found to changes in rabbit abundance, but not for the other prey types. Cats continued to prey heavily on rabbits even after a 90% decline in rabbit abundance occurred, which coincided with the advent of Rabbit Calicivirus Disease (RCD). House mice (Mus domesticus) increased in importance in the diet ten months post-RCD. Although the abundance of cats was correlated with the abundance of some prey species, other factors may have influenced the observed patterns; these are discussed.


2000 ◽  
Vol 22 (1) ◽  
pp. 44 ◽  
Author(s):  
SJ Holdaway ◽  
PC Fanning ◽  
DC Witter

Recent erosion in arid regions of western NSW has exposed large areas that are scattered with stone artefacts manufactured by Aboriginal people in prehistory. These exposures offer an opportunity for archaeologists to study the artefacts abandoned by Aboriginal people through time and to compare those artefacts that accumulate in different parts of the landscape. To reconstruct the nature of prehistoric behaviour in the rangelands, two approaches are needed. First, the geomorphological context of the artefacts needs to be considered since exposure of the artefacts is a function of landscape history. Second, large areas (measured in thousands of square metres) and large numbers of artefacts need to be considered if patterns reflecting long-term abandonment behaviour by Aboriginal people are to be identified. This paper reports on the Western New South Wales Archaeological Program (WNSWAP) which was initiated in 1995 to study surface archaeology in the rangelands. Geomorphological studies are combined with artefact analysis using geographic information system software to investigate Aboriginal stone artefact scatters and associated features such as heat retainer hearths, in a landscape context. Results suggest that apparently random scatters of stone artefacts are in fact patterned in ways which inform on prehistoric Aboriginal settlement of the rangelands. Key words: Aboriginal stone artefacts; rangelands; landscape archaeology; geomorphology; GIs


1998 ◽  
Vol 46 (2) ◽  
pp. 153 ◽  
Author(s):  
Damon L. Oliver

The regent honeyea ter, Xanthomyza phrygia, is an endangered woodland bird whose range and population size have decreased in the last thirty years. Suggested reasons for this decline include abnormal breeding behaviour, poor reproductive output, and excessive inter- and intra-specific aggression. This study investigated the breeding behaviour and aggressive interactions of regent honeyeaters during the nest construction, incubation, nestling, and fledgling stages in two consecutive breeding seasons in the Bundarra–Barraba region near Armidale, New South Wales. The female was entirely responsible for nest construction and incubation, which is typical of many honeyeaters. Both parents fed the nestlings, and at a similar rate, although only the female brooded chicks on the nest. Both parents fed the fledglings. The mean frequency at which nestlings (23 times per hour) and fledglings (29 times per hour) were fed is the highest published rate of any non-cooperative honeyeater. Breeding males were involved in significantly more aggressive interactions with conspecifics and other nectarivores than were females, although the overall percentage of day-time spent in aggression for both sexes was low (2.5%). It appears that abnormal breeding behaviour, poor reproductive effort, or excessive aggression are not experienced by this species in northern New South Wales, and that other factors are likely to be responsible for its current low population level.


2004 ◽  
Vol 17 (3) ◽  
pp. 327 ◽  
Author(s):  
Trisha L. Downing ◽  
Marco F. Duretto ◽  
Pauline Y. Ladiges

A morphological study of herbarium and field-collected specimens, using phenetic techniques of agglomerative classification, ordination and minimum spanning trees, and covering the geographic range of the Holly Grevillea, G.�ilicifolia (R.Br.) R.Br. sensu lato, has resulted in the recognition of three species and four subspecies. The taxa are based on leaf form, noted by previous authors to be highly variable between populations. The taxa recognised here are G.�ilicifolia, G.�ilicifolia subsp. ilicifolia (typical, kite-shaped leaf form), G.�ilicifolia subsp. lobata (F.Muell.) T.L.Downing comb. et stat. nov. (oak-shaped leaf form), G.�dilatata (R.Br.) T.L.Downing comb. et stat. nov. (fan-shaped leaf form), G.�angustiloba (F.Muell.) T.L.Downing comb. et stat. nov., G.�angustiloba subsp. angustiloba (narrow-lobed leaf form) and G.�angustiloba subsp. wirregaensis T.L.Downing subsp. nov. (very narrow-lobed leaf form). The rank of subspecies is used where there are some intermediate plants between forms. Grevillea ilicifolia subsp. ilicifolia is the most widespread taxon and occurs in South Australia, western Victoria and in two localities in New South Wales. Grevillea angustiloba subsp. wirregaensis has the most restricted range, occurring in semi-arid regions near Wirrega in South Australia. Grevillea dilatata is largely endemic to Kangaroo Island, South Australia.


1998 ◽  
Vol 25 (4) ◽  
pp. 409 ◽  
Author(s):  
Damon L. Oliver

The dietary items fed to regent honeyeater, Xanthomyza phrygia, nestlings and fledglings by adults were recorded in two consecutive breeding seasons in the Bundarra–Barraba region west of Armidale, New South Wales. Insects were the most common dietary items fed to juveniles (53% of identified items), followed by lerp (26.5%) and nectar (20.5%). Nestlings were fed mostly insects (58% of feeds), and carbohydrates (nectar and lerp) made up the rest of their diet. Fledglings, however, were fed mainly carbohydrates (nectar and lerp comprised 61.2% of all items) while protein from insects was the other major component of their diet. Males tended to feed juveniles more insects than did females, although there were no significant divisions of labour between parents in selecting dietary items for nestlings or fledglings. This study highlights the importance of insects and lerp in the diet of juvenile regent honeyeaters, and the diversity of plant species on which their parents foraged. The species shows a broader resource selection than was found in previous studies which considered the species to be highly nectarivorous and selective for a few key eucalypt species. The importance of insects and carbohydrates other than nectar in the diet of the regent honeyeater needs to be recognised in the development of conservation strategies for the species.


1980 ◽  
Vol 7 (3) ◽  
pp. 385 ◽  
Author(s):  
CM Kemper

A total of 291 P. novaehollandiae were observed during a 4-y study in the Nelson Bay and Smith Lake regions of New South Wales. Reproductive organs were examined from males and females, May 1972-May 1974; reproductive condition of females was noted during a CMR study, August 1974-July 1976. Breeding seasons (conceptions and births) occurred between August and early January (4-5 months) in the first 3 years and between September and March (7 months) in the last year. Second-year females produced three or four litters in short seasons, four or five litters in the long season and up to 20 offspring per season. First-year females produced one litter in short seasons and one or two litters in the long season. Mean litter size was 4.56 (2-6). Ovarian follicles were largest in September and smallest in May. Small, inactive CL persisted in parous females until May. Placental scars were present in all sampled months. Vaginae remained closed during the non-breeding season. In mature males testes and epididymides contained sperm from July to March. Vesicular, prostate and preputial glands were enlarged and secretory from September to December. Testes were smallest and least developed in May and June. Males were divided into five categories depending on age and overall reproductive condition. Sexual maturity was reached in the breeding season of birth by some males (33%) and females (13-88%). More females matured early when population density was low. Food abundance and quality may have been important variables in regulating the timing of the breeding season.


2000 ◽  
Vol 48 (1) ◽  
pp. 21 ◽  
Author(s):  
Hugh A. Ford ◽  
Steve Trémont

Most endemic Australian passerines that have been studied display long breeding seasons, multiple nesting attempts, small clutches, low annual productivity, high longevity and a high incidence of cooperative breeding. We compare the life histories of two large endemic honeyeaters (Meliphagidae) near Armidale, New South Wales. Red wattlebirds, Anthochaera carunculata, have a long breeding season, with many nesting attempts and clutches of two eggs, similar to other honeyeaters whose breeding biology has been studied. Noisy friarbirds, Philemon corniculatus, which are spring and summer visitors to the study area, have shorter breeding seasons, usually making one attempt and have a modal clutch size of three. Both species had incubation and nestling periods of about 16 days. Friarbirds apparently have a laying interval of 24 hours, the same as other honeyeaters, but unlike some other endemic passerines, which have laying intervals of 48 hours. Breeding success did not differ between the species, with young fledging from 32.7% of wattlebird nests and 40.9% of friarbird nests. The reproductive strategy of the noisy friarbird thus differs quantitatively from the apparent norm for other honeyeaters and many other Australian endemic passerines.


2007 ◽  
Vol 34 (5) ◽  
pp. 342 ◽  
Author(s):  
James P. Dawson ◽  
Andrew W. Claridge ◽  
Barbara Triggs ◽  
David J. Paull

The relationship between the diet of the spotted-tailed quoll (Dasyurus maculatus) and the abundance of its prey was investigated in rain-shadow woodland habitat in southern New South Wales for one year before and two years after a high-intensity, broad-scale wildfire. Scats were variously collected from quoll latrines and live-trapped animals during winter for each of the three years and analysed to determine prey items. Estimates of abundance of key ground-dwelling and arboreal medium-sized mammals were simultaneously obtained using plot-based survey techniques and spotlighting. Over the duration of the study, quoll diet was dominated by medium-sized mammals, particularly brushtail possums (Trichosurus spp.) and lagomorphs (rabbit and hare), followed by small and large-sized mammals. After the fire there was a shift in utilisation of food resources in response to significant changes in prey availability. Monitoring revealed that brushtail possums, lagomorphs and bandicoots were all significantly less abundant in the winter following the fire, and populations of lagomorphs, but not possums, then increased in the second winter after the fire. Quolls adapted to this by taking significantly more lagomorphs in each of the two years after the fire and by taking advantage of a short-term increase in the availability of carrion. The results of this study reaffirm that the spotted-tailed quoll is adaptable in its utilisation of available food, and that fires are not necessarily detrimental to the species and its prey base.


Sign in / Sign up

Export Citation Format

Share Document