scholarly journals Response of Australian pied oystercatchersHaematopus longirostristo increasing abundance of the beach bivalve preyDonax deltoides

2018 ◽  
Author(s):  
Stephen L. Totterman

AbstractThis study measured the response of Australian pied oystercatchersHaematopus longirostrison South Ballina Beach, New South Wales, Australia during a recovery in the stock of the primary prey speciesDonax deltoides, a large beach clam and commonly known as the ‘pipi’. It was predicted that oystercatcher counts would increase when pipi abundance increased (numerical response) and that oystercatcher feeding rates would also increase (functional response). Between Oct 2009 and Mar 2015, mean pipi density increased from c. zero to 30 pipis/m2. Mean oystercatcher feeding rates increased to an asymptote of c. 0.26 pipis/min. Breeding season mean counts of adult-plumage oystercatchers increased from 23 to 43, largely driven by non-territorial birds. Prey size selection was absent, both among different prey types and among pipis > 20 mm. This report provides some insights into the feeding ecology of oystercatchers on sandy ocean beaches that should be valuable in planning future studies.

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.


1981 ◽  
Vol 29 (2) ◽  
pp. 205 ◽  
Author(s):  
RA How

In adjacent areas in north-eastern New South Wales, T. vulpecula occurs in the open forest and woodland and T. caninus occurs in the closed and tall open forest; both species are found in the pine plantation. T. vulpecula has a single breeding season in autumn when all females 1 y old and older reproduce. The young become independent around 175 days old and disperse at up to 2 y old. Mortality is low (15%) among dependent young but considerably higher among independent dispersing individuals. T. caninus also has a single autumn breeding season. The young become independent around 240 days old but disperse after 18-26 months, females moving before males. Mortality is high (56%) among dependent young but less so among subadults. An adult sex ratio of parity is the result of a higher survival among subadult males than females offsetting the reverse in adults. Some 2-y-old and all 3-y-old females reproduce but a few older females fail to breed in certain years. There is evidence that the high mortality of dependent young and failure of older females to breed is associated with offspring of previous years remaining in the population. Adult males and females appear to form a pair-bond. Population parameters of T. vulpecula described from other areas show considerable variation; this flexibility in population strategy explains the species' success in occupying a diversity of habitats and rapidly colonizing new areas.


2003 ◽  
Vol 9 (2) ◽  
pp. 157
Author(s):  
Graham R. Fulton

THIS monograph presents the status of all mammal, bird, reptile and frog species in NSW and compares ecological attributes at the familial level. It has been compiled by a diverse array of experts including the authors. The monograph identifies the status of each species and provides their ecological attributes from which patterns of decline (or increase) may be determined. It provides the first official list of vertebrate fauna in NSW and gives scores for each variable affecting species status, which explain the reasons for their inclusion or exclusion in the Threatened Species Conservation Act (1995). The most significant function of the monograph is the establishment of baseline data for future studies. In addition, the report identifies the magnitude of problems faced, provides new material, ideas and direction for conservation programs.


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.


1966 ◽  
Vol 14 (2) ◽  
pp. 185 ◽  
Author(s):  
JD Dunsmore

(1) Trichostrongylus retortaeformis (Zeder, 1800) in wild rabbits in Australia has been studied by more or less regular sampling of rabbit populations in four climatically different areas of eastern Australia. (2) In a semi-arid locality in north-western New South Wales, T. retortaeformis is rarely found; in a subtropical area of south-central Queensland it was found only in small numbers and many rabbits were apparently free of infection. In an area of the Riverina district of New South Wales most rabbits were infected but parasite numbers were rarely high. The highest levels of infection were recorded at a site in a subalpine area of New South Wales. (3) It was possible to build up a detailed picture of the dynamics of T. retortaeformis in rabbits throughout their lives at Snowy Plains, the subalpine site, in which breeding of rabbits is limited to a relatively few months each year. During their first 6-8 months of life (prior to their first breeding season) male and female rabbits carry moderate numbers of T. retortaeformis with the males carrying somewhat more parasites than the females. During the breeding season T. retortaeformis numbers in female rabbits increase very markedly (about tenfold) while numbers in male rabbits are decreasing to a low level (their lowest during the year). Following breeding, worm numbers in female rabbits drop quite rapidly while those in males increase to a similarly moderate level. Apparently a similar cycle of events occurs during each 12 months of a rabbit's life. (4) At Urana, in the Riverina plain region the cycle of events described above for Snowy Plains could not be seen, although T. retortaeformis was found in moderate numbers. This may have been due to infrequent sampling, lack of a defined rabbit breeding season, or some other factor.


2000 ◽  
Vol 22 (1) ◽  
pp. 35 ◽  
Author(s):  
RE Woods ◽  
FD Ford

This study examined aspects of behaviour in a captive colony of smoky mice, Pseudomys fumeus, over a two year period. Wherever possible behaviours observed in the captive population are compared to data collected in a study of a wild population in south-eastern New South Wales. This paper provides the first recorded observations of behavior in this species. Both captive and wild populations of P. fumeus display strictly nocturnal circadian activity rhythms. In the captive study, P. fumeus were found to exhibit social interactions similar to some previously studied Pseudomys species. However, in the wild, the species was found to communally nest during the breeding season, behaviour not observed in other Pseudomys from similar habitats. P. fumeus in captivity can have more than two litters in one breeding season which suggests that their reproductive parameters are more flexible than previous studies of wild populations have shown. Field data indicate that post-partum oestrus can occur in this species, and that gestation lasts for approximately 30 days, although these observations are based on a small sample.


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.


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