scholarly journals Population dynamics of an outbreak population of house mice (Mus domesticus) in the irrigated rice-growing area of Australia

1994 ◽  
Vol 21 (5) ◽  
pp. 583 ◽  
Author(s):  
R Boonstra ◽  
TD Redhead
Keyword(s):  
Population Dynamics ◽  
Body Weight ◽  
New South ◽  
House Mice ◽  
Mus Domesticus ◽  
Male Body ◽  
Irrigated Rice ◽  
South Wales ◽  
Low Levels ◽  
Social Suppression

Conditions appear ideal for annual plagues of house mice in irrigated rice-growing areas of Australia, yet plagues in these areas usually coincide with those in the dry farms. In an irrigated rice crop near Jerilderie, New South Wales, we examined in detail the demography of an incipient plague population of Mus domesticus. Breeding occurred from winter 1983 to autumn 1984 and the population increased from low levels to plague levels (2500 ha-1) by May. We found no evidence for a rigid territorial social organisation. Dispersal of tagged animals was low throughout the breeding season, yet between 60% and 76% of the trappable population was new each trapping session. Testosterone levels increased when the average male body weight was low, suggesting that social suppression of reproduction was not occurring. We conclude that plagues in these areas can develop within approximately 12 months from the onset of drought-breaking rains.

Evaluation of Bromadiolone Against House Mouse (Mus Domesticus) Populations in Irrigated Soybean Crops. Ii. Economics.

1991 ◽  
Vol 18 (3) ◽  
pp. 275 ◽  
Author(s):  
GR Singleton ◽  
LE Twigg ◽  
KE Weaver ◽  
BJ Kay
Keyword(s):  
House Mouse ◽  
New South ◽  
New South Wales ◽  
House Mice ◽  
Mus Domesticus ◽  
Crop Losses ◽  
South Wales ◽  
Crop Density ◽  
Bait Stations

The economics of controlling house mice [M. musculus] using 0.005% bromadiolone-treated wheat placed in bait stations within soyabean crops was evaluated in New South Wales during 1989 when mouse densities were approx. 200-300/ha. Damage by mice to soyabean crops was assessed up to 200 m into 2 crops (1 with bait and 1 without) on each of 2 farms just before baiting, and 22 and 42 d after baiting. Mouse damage in each crop was always <10%, and was greatest in patches of high crop density. Damage was similar at the crop perimeters and up to 100 m into the crops, but 200 m from crop perimeters, damage was less prevalent. By 42 d after baiting, the differences in crop losses relative to pre-baiting damage levels were minimal. Estimates of losses caused by mice in 3 of the principal soyabean growing regions of New South Wales were obtained from all farmers who grew soyabeans in 1988-89. The combined losses caused by mice to growers in these regions in 1989 was about $A2 million.

Feeding ecology and population dynamics of the feral cat (Felis catus) in relation to the availability of prey in central-eastern New South Wales

1999 ◽  
Vol 26 (5) ◽  
pp. 593 ◽  
Author(s):  
Robyn Molsher ◽  
Alan Newsome ◽  
Chris Dickman
Keyword(s):  
Oryctolagus Cuniculus ◽  
Prey Species ◽  
New South ◽  
New South Wales ◽  
Felis Catus ◽  
House Mice ◽  
Minor Components ◽  
Feral Cat ◽  
South Wales ◽  
Central Eastern

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.

scholarly journals Lifetime reproductive success in a population of female red kangaroos Macropus rufus in the sheep rangelands of western New South Wales: Environmental effects and population dynamics

2004 ◽  
Vol 26 (1) ◽  
pp. 45 ◽  
Author(s):  
AD Bilton ◽  
DB Croft
Keyword(s):  
Population Dynamics ◽  
Reproductive Success ◽  
Environmental Conditions ◽  
New South ◽  
New South Wales ◽  
Reproductive Potential ◽  
Lifetime Reproductive Success ◽  
South Wales ◽  
Macropus Rufus ◽  
Initial Starting

Female reproductive success and the recruitment of offspring to the next generation are key components of animal population dynamics. With an annual commercial harvest of between 13 and 22% of the red kangaroo (Macropus rufus) population, it is increasingly important that these processes are understood. We used data on the reproductive success of 33 free-ranging female M. rufus on Fowlers Gap station in far western New South Wales to determine the expected lifetime reproductive success (LRS) of females within an unharvested population. We also designed a model to generate predictions about female LRS incorporating empirical relationships between a mother?s reproductive success and maternal age, environmental conditions and the sex and survivorship of a previous reproductive attempt. Results from observations on female LRS (calculated from annual weaning rates) and those generated by the model predict that female M. rufus on ?Fowlers Gap? wean, on average, 3.7 young in a lifetime (ranges 0 - 11 and 0 - 20, respectively); representing only 41% of their maximum reproductive potential. Manipulation of initial starting conditions allowed the effect of varying environmental conditions on female LRS to be explored. The condition of the environment when females commence breeding does not appear to significantly affect their overall lifetime reproductive output. However, the occurrence of drought does. Females experiencing two droughts in a lifetime did not live as long and weaned fewer offspring and grandoffspring (from their daughters) than those females experiencing only one drought in a lifetime. In addition to the adverse effect of drought on the reproductive success of female M. rufus in this study, we suggest that, given the relatively high and stable population densities of M. rufus on ?Fowlers Gap?, other mechanisms (acting primarily on juvenile survival) must exist which limit population growth.

Effect of prolonged undernutrition on the recovery and reproductive performance of maiden Merino ewes

1967 ◽  
Vol 7 (24) ◽  
pp. 7 ◽  
Author(s):  
P McInnes ◽  
TJ Grainger ◽  
MD Smith
Keyword(s):  
Body Weight ◽  
Reproductive Performance ◽  
New South ◽  
New South Wales ◽  
The Other ◽  
First Year ◽  
Treatment Groups ◽  
South Wales ◽  
Feeding Trials ◽  
The Mean

Data are presented on the recovery and reproductive performance of 2 1/2-year-old maiden Merino ewes after a prolonged period of undernutrition. The 217 sheep had been hand-fed on a submaintenance ration in pen feeding trials at Glenfield, New South Wales. During the seven months of the trials they had lost 6 kg (28 to 22 kg) body weight. They were transported to Condobolin in south-western New South Wales, divided into two treatment groups and run on good quality pastures. One group was joined immediately (May 1959) and again ten months later, and the other group was mated after six months at Condobolin (in October 1959) and again 12 months later. The ewes recovered rapidly. The mean weight of both groups had reached 30 kg within six weeks and 40 kg within six months. In the first year 73 of the 100 May-mated ewes bore lambs, but only 38 of these lambs were weaned. Ewes bearing lambs had a higher body weight at the start of joining and gained more during joining than the barren ewes. At the other three joinings (October 1959, May 1960, October 1960) lambing percentage was from 86-89 and weaning percentage from 62-69-both normal for the district. The proportion of twin lambs (3-6 per cent) was low. Wool weight in 1959 was not affected by time of mating or by pregnancy.

Movements of Sympatric Red Kangaroos, Macropus-Rufus, and Western Grey Kangaroos, Macropus-Fuliginosus, in Western New-South-Wales

1988 ◽  
Vol 15 (3) ◽  
pp. 339 ◽  
Author(s):  
D Priddel ◽  
G Wellard ◽  
N Shepherd
Keyword(s):  
Population Dynamics ◽  
National Park ◽  
New South ◽  
New South Wales ◽  
South Wales ◽  
Macropus Rufus

Between July 1979 and November 1980 a total of 261 red kangaroos, Macropus rufus, (216F; 45 M) and 170 western grey kangaroos, M. fuliginosus, (136F;34M) were caught and tagged with individually recognisable collars. Between July 1979 and January 1986, 1751 sightings of tagged individuals were recorded. Information gained from these sightings was used to assess how far each kangaroo ranged. More than 90% of individuals of either species did not range far (<9 km for reds; <6 km for western greys) even when local pastures were severely depleted during drought. A few individuals dispersed much further-up to 323 km. On average, red kangaroos ranged further than western greys. Kangaroos on Kinchega National Park ranged no less or no further than those on an adjacent pastoral leasehold. At least 17 tagged individuals crossed the macropod-deterrent fence surrounding Kinchega; several crossed repeatedly. Dispersal of kangaroos from Kinchega was slight, supporting the hypothesis of Bayliss (1985) that dispersal has no significant impact on population dynamics.

Comparative responses of Lolium perenne and Bothriochloa macra to temperature, moisture, fertility and defoliation

1976 ◽  
Vol 27 (6) ◽  
pp. 769 ◽  
Author(s):  
SJ Cook ◽  
A Lazenby ◽  
GJ Blair
Keyword(s):  
Lolium Perenne ◽  
Competitive Ability ◽  
New South ◽  
Moisture Stress ◽  
Low Fertility ◽  
High Fertility ◽  
South Wales ◽  
Temperature Regimes ◽  
Low Levels ◽  
Moisture Conditions

Lolium perenne and Bothtriochloa macra were grown alone and In 1/1 mixtures In pot culture under molsture stress and moisture non-limiting conditions at both high and low levels of fertility, they were grown In three controlled environment cabinets operating at either 16/10°, 23/17° or 31/25°C, and defoliated to either 1 cm or 4 cm from the crown at each of two harvests.Temperature was the dormant factor differentiating the growth and competitive ability of both species Lolium grew best In the 16/10° and 23/17°C temperature regimes, production declining at 31/25° In contrast, Bothriochloa made very little growth a1 16/10° and responded linearly to measuring temperature. Both species responded similarly to increasing fertility and favourable moisture conditions, although such treatments had no effect on Bothriocochloa in the 16/10°C temperature regime Bothtriochloa was more tolerant of low fertility and moisture stress than was Loliurn, especially at 31/25° Lolium yielded more, and competed successfully with Bothtriochloa, only under conditions of high fertility and In the absence of moisture stress at temperatures up to 23/17°C Defoliation intensity had little effect on the total dry matter yields of either species, although it did influence the proportion of leaf to head and stem of Bothtriochloa. The likely implications of the results on the competitive relationships of the two species In the field In the Northern Tablelands environment of New South Wales are discussed

Population Dynamics of the Australian Plague Locust, Chortoicetes Terminifera (Walker) in Central Western New South Wales. Ii. Factors Influencing Natality and Survival.

1982 ◽  
Vol 30 (2) ◽  
pp. 199 ◽  
Author(s):  
RA Farrow
Keyword(s):  
Biological Control ◽  
Population Dynamics ◽  
Natural Enemies ◽  
New South ◽  
New South Wales ◽  
Development Stages ◽  
Factors Influencing ◽  
South Wales ◽  
Savannah Woodland ◽  
Australian Plague Locust

Unrealized natality and mortalities at successive development stages were measured during synchronized breeding by populations of the Australian plague locust. Studies were made over a 3-y period, covering nine generations, on small plots situated in pastures derived originally from savannah woodland in central western New South Wales. Variations in natality and mortalities were influenced more by variation in soil moisture, primarily through its effect on pasture conditions, than by the effects of natural enemies; these variations were closely correlated with seasonal rainfall. Unidentified losses, independent of known variables, were recorded in the hopper stage and were highest in the hatchling. Such losses invariably exceeded 60% even under the most favourable conditions encountered in the field during the study period. The quantitative relationships established in this study between the plague locust and its natural enemies and other environmental factors suggest that prospects for the biological control of this pest by either native or introduced species are poor.

scholarly journals The population dynamics of perennial chenopod shrubs in semi-arid western New South Wales.

1990 ◽  
Vol 12 (1) ◽  
pp. 29 ◽  
Author(s):  
DJ Eldridge
Keyword(s):  
Population Dynamics ◽  
Population Ecology ◽  
Arid Zone ◽  
Seedling Survival ◽  
New South ◽  
New South Wales ◽  
South Wales ◽  
Semi Arid

This thesis deals with some aspects of the population ecology of arid zone perennial chenopod shrubs. It examined the effects of grazing on the population dynamics of Atriplex vesicaria, Maireana astrotricha and Maireana pyramidata, the influence of weather on recruitment and survival of Atriplex vesicaria and the effects of various microtopographical features on seedling survival of Atriplex vesicaria.

The influence of grazing by cattle and sheep on the population dynamics of Bladder Saltbush (Atriplex Vesicaria) and white top (Danthonia caespitosa).

1980 ◽  
Vol 2 (2) ◽  
pp. 208 ◽  
Author(s):  
RD Graetz
Keyword(s):  
Population Dynamics ◽  
New South ◽  
New South Wales ◽  
Population Data ◽  
Plant Population ◽  
Rainfall Pattern ◽  
South Wales ◽  
A Site ◽  
Stocking Rates ◽  
Cattle And Sheep

Plant population data for the pass white-top (Danthonia caespitosa) and for bladder saltbush (Atriplex vesicaria) were collected for four years from a pasture continuously grazed by either cattle or sheep (at equivalent stocking rates) at a site near Booligal, New South Wales. During the four years of the experiment the cattle and sheep had different Impacts on the grass and scrub components of the pasture Sheep tended to deplete the numbers of pass plants far more than did cattle, whereas saltbush shrub numbers here little affected by either type of stock. The rainfall pattern experienced throughout the experiment had a far greater influence on the survival of both grass and shrub than did grazing.

Alternaria toxins in weather-damaged wheat and sorghum in the 1995-1996 Australian harvest

1997 ◽  
Vol 48 (8) ◽  
pp. 1249 ◽  
Author(s):  
D. J. Webley ◽  
K. L. Jackson ◽  
J. D. Mullins ◽  
A. D. Hocking ◽  
J. I. Pitt
Keyword(s):  
Alternaria Alternata ◽  
Primary Infection ◽  
New South ◽  
Geographical Location ◽  
Monomethyl Ether ◽  
The Other ◽  
Tenuazonic Acid ◽  
Alternariol Monomethyl Ether ◽  
South Wales ◽  
Low Levels

Weather-damaged wheat from northern New South Wales in 1995-96 was heavily infected with the fungus Alternaria alternata. The mycotoxins tenuazonic acid, alternariol, and alternariol monomethyl ether were detected at low levels which corresponded with the degree of A. alternata infection and the geographical location. Sorghum and undamaged wheat from the same region also showed moderate levels of A. alternata infection and low levels of tenuazonic acid but none of the other toxins. These mycotoxins were not found in weather-damaged wheat from other areas of Australia where the primary infection was by A. infectoria rather than A. alternata.

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