Population Dynamics of White Sharks in Spencer Gulf, South Australia

1996 ◽  
pp. 401-414 ◽  
Author(s):  
WESLEY R. STRONG ◽  
DONALD R. NELSON ◽  
BARRY D. BRUCE ◽  
RICHARD D. MURPHY
Keyword(s):  
Population Dynamics ◽  
South Australia

Population ecology of the Australian frog Crinia signifera: larvae

1999 ◽  
Vol 26 (1) ◽  
pp. 81 ◽  
Author(s):  
I. Williamson ◽  
C. M. Bull
Keyword(s):  
Population Dynamics ◽  
Population Ecology ◽  
South Australia ◽  
Predation Pressure ◽  
Temporary Pools ◽  
Permanent Pond ◽  
Complete Failure ◽  
One Year ◽  
Predator Community

There are few published studies of the population ecology of the larvae of Australian native anurans. In this study we report on the population dynamics of the larvae of the Australian frog Crinia signifera at a study site near Bridgewater in the Adelaide Hills, South Australia. The predator community was also monitored to provide an indication of the importance of predation in influencing the population dynamics of C. signifera larvae. Pool drying meant larvae failed to metamorphose from temporary pools in all years of the study. In a permanent pond, mortality was high and variable, with an average of 10% survival over the three years of the study. There was a complete failure to recruit to the terrestrial phase in one year. Predation pressure was thought to be the most important source of mortality in the permanent pond, although predator numbers varied considerably between and within years. When combined with information on the population ecology of the embryonic (Williamson and Bull 1994) and terrestrial (Williamson and Bull 1996) stages, the data suggest that the aquatic phase is the key phase in the population dynamics of this species.

Impact of rabbit haemorrhagic disease on introduced predators in the Flinders Ranges, South Australia

2002 ◽  
Vol 29 (6) ◽  
pp. 615 ◽  
Author(s):  
C. Holden ◽  
G. Mutze
Keyword(s):  
Population Dynamics ◽  
Physical Condition ◽  
South Australia ◽  
Feral Cats ◽  
Flinders Ranges ◽  
Introduced Predators ◽  
Rabbit Haemorrhagic Disease ◽  
Haemorrhagic Disease ◽  
The Impact

The impact of rabbit haemorrhagic disease (RHD) on the population dynamics and diet of foxes and feral cats was studied in the Flinders Ranges, South Australia. Populations of both foxes and cats decreased substantially some 6–10 months after the advent of RHD, when rabbit numbers were reduced by 85%. The diet of foxes changed as a result of reduced rabbit numbers, with much less rabbit and more invertebrates and carrion being eaten. The physical condition of foxes showed little change after RHD. The diet of cats did not change markedly, but their physical condition was substantially poorer than before RHD. Total predation on native fauna is considered to have decreased after RHD.

Variation in population dynamics and movement patterns between two geographically isolated populations of the dusky hopping mouse (Notomys fuscus)

2006 ◽  
Vol 33 (3) ◽  
pp. 223 ◽  
Author(s):  
K. E. Moseby ◽  
H. Owens ◽  
R. Brandle ◽  
J. K. Bice ◽  
J. Gates
Keyword(s):  
Population Dynamics ◽  
South Australia ◽  
Isolated Populations ◽  
North East ◽  
South West ◽  
Linear Distance ◽  
Large Fluctuations ◽  
Study Sites ◽  
Night Period ◽  
Very High

The ecology of the dusky hopping mouse (Notomys fuscus) was studied at Pelican Waterhole in south-west Queensland and Montecollina Bore in north-east South Australia over an eight-year period. Population parameters of N. fuscus differed markedly between the two study sites. Whilst the population at Montecollina Bore exhibited large fluctuations in size, captures at Pelican Waterhole were lower but more consistent. Recaptures between sessions at Montecollina Bore peaked at 60% but no individuals were recaptured at Pelican Waterhole. No evidence of seasonal breeding was recorded at either site. Male N. fuscus captured at Montecollina Bore were significantly heavier (average 31.4 g) than Pelican Waterhole animals (average 26.6 g). Over a 1–4-night period, the maximum linear distance moved by radio-collared individuals was 1.5 km (average 481 m) at Pelican Waterhole and 400 m (average 199 m) at Montecollina Bore. Differences in population dynamics between the two sites are ascribed to food availability and habitat quality. Whilst Pelican Waterhole may constitute a more stable, less degraded environment, Montecollina Bore appears to be defined by periods of either very high or very low resource availability depending on rainfall. The abundance of dingoes and low cat and fox activity may contribute to the persistence of N. fuscus at the two study sites.

Population dynamics in rural South Australia

1992 ◽  
Vol 8 (1) ◽  
pp. 29-51 ◽  
Author(s):  
G.J. Hugo ◽  
P.J. Smailes
Keyword(s):  
Population Dynamics ◽  
South Australia ◽  
Rural South

Status of warru (Petrogale lateralis MacDonnell Ranges race) in the Anangu Pitjantjatjara Yankunytjatjara Lands of South Australia. 1. Distribution and decline

2011 ◽  
Vol 33 (2) ◽  
pp. 135 ◽  
Author(s):  
Matthew J. Ward ◽  
Roman Urban ◽  
John L. Read ◽  
Anika Dent ◽  
Thalie Partridge ◽  
...  
Keyword(s):  
Population Dynamics ◽  
South Australia ◽  
Recent Information

Surveys for warru (Petrogale lateralis MacDonnell Ranges race) were conducted in targeted areas of the Anangu Pitjantjatjara Yankunytjatjara (APY) Lands in order to clarify the distribution and status of the taxon in South Australia. Presence was determined by animal sightings or fresh scats. The study identified extant warru sites adjacent to known colonies in the Musgrave and Tomkinson Ranges, indicating that, in both locations, warru probably occur as larger metapopulations. The study highlighted that warru has disappeared from 93% of its former range across South Australia, and from 88% of its stronghold in the APY Lands. Accounting for recent information on population dynamics, this study has confirmed that warru are ‘Endangered’ in South Australia, and a more thorough assessment of the race’s current national distribution and status is required.

The population dynamics of the mediterranean snails Cernuella virgata, Cochlicella acuta (Hygromiidae) and Theba pisana (Helicidae) in pasture - cereal rotations in South Australia: a 20-year study

2008 ◽  
Vol 48 (12) ◽  
pp. 1514 ◽  
Author(s):  
G. H. Baker
Keyword(s):  
Population Dynamics ◽  
Near Field ◽  
South Australia ◽  
Habitat Choice ◽  
Snail Species ◽  
Large Numbers ◽  
Yorke Peninsula ◽  
Sampling Scale ◽  
Theba Pisana ◽  
Peak Abundance

The snails Cernuella virgata, Cochlicella acuta and Theba pisana are introduced pests of grain crops and pastures in southern Australia. The population dynamics of these three species of snail were studied for 20 years in two adjacent fields where they coexisted on a farm on the Yorke Peninsula in South Australia. The fields were used for pasture–cereal rotations. Surveys were conducted in autumn and spring each year, coinciding respectively with the start of the breeding season and peak abundance of snails (mostly juveniles). Populations varied greatly in abundance between years and between species, but snails were generally most common in spring, in wet years, especially those with wet autumns and wet springs. Rainfall early in a particular year (i.e. at sowing of crops in autumn) can thus be used to predict the likelihood of heavy snail infestations later in spring (i.e. at harvest). In contrast, the abundance of adult snails in autumn was a poor predictor of the subsequent abundance of juvenile snails in spring, especially in crops. There were no significant correlations, at field scale, between the average abundance of the three species of snail in spring, in either pastures or crops. However, at a sampling scale of 0.25 m2, there were consistent, negative relationships between the abundance of all three snail species. Such patterns may reflect either competitive interactions between snails or subtle differences in micro-habitat choice. Patterns in the abundance of snails (e.g. large numbers near field edges) were suggestive of occasional invasion from dense populations in adjacent fields.

The Biology and Main Causes of Changes in Numbers of the Rose Aphid, Macrosiphum Rosae (L.), On Cultivated Roses in South Australia.

1977 ◽  
Vol 25 (2) ◽  
pp. 269 ◽  
Author(s):  
DA Maelzer
Keyword(s):  
Computer Simulation ◽  
Population Dynamics ◽  
Natural Populations ◽  
South Australia ◽  
Flower Buds ◽  
Young Leaves ◽  
Macrosiphum Rosae ◽  
The Rose

In South Australia, M. rosae is anholocyclic on Rosa, reproducing parthenogentically and viviparously all year round. It feeds mainly on the young leaves and developing flower-buds of hybrid tea roses. The fate of a colony of aphids on a single bud is a function of temperature, rainfall, predation, the time for which the bud remains favourable for the aphids, and the influence of crowding on alatiform production and on dispersal of apterae by walking or dropping off. The numbers of aphids on cultivated hybrid tea roses in a rose garden had three peaks in spring-summer which coincided with three flushes of growth of the rose. The first peak, in spring, was the highest; thereafter numbers of aphids were relatively low, mainly because of predation by three species of native predators, namely the hemerobiid Micromus tasmaniae, the syrphid Melangyna viridiceps and the ladybird Leis conformis. The study was a prelude to computer simulation of the population dynamics of the aphid which will be used to investigate the problem of the regulation of density in natural populations of aphids.

Status of warru (Petrogale lateralis MacDonnell Ranges race) in the Anangu Pitjantjatjara Yankunytjatjara Lands of South Australia. 2. Population dynamics

2011 ◽  
Vol 33 (2) ◽  
pp. 142 ◽  
Author(s):  
Matthew J. Ward ◽  
Laura Ruykys ◽  
Jason van Weenen ◽  
Siobhan de Little ◽  
Anika Dent ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Red Fox ◽  
South Australia ◽  
Free Water ◽  
Juvenile Survival ◽  
Winter Rainfall ◽  
Population Sizes ◽  
Access To Water ◽  
Survey Results ◽  
Reproductive Rates

The population dynamics of warru (Petrogale lateralis MacDonnell Ranges race) were studied in the Anangu Pitjantjatjara Yankunytjatjara Lands, South Australia, in order to inform management and better understand the race’s conservation ecology. Mark–recapture between 2005 and 2010 at the three largest known remaining colonies, followed by POPAN modelling, indicated that population sizes were 23 at New Well and 24 at Alalka in the Musgrave Ranges, and 14 at Kalka in the Tomkinson Ranges. Taking into account recent survey results, the study confirmed that warru are ‘Endangered’ in South Australia. However, there is potential for the recovery of the race, with high average reproductive rates (in the Musgrave Ranges >90% of reproductively active females had pouch young), even sex ratios and relatively high adult survivorship (>75%). Juvenile survival (51%), however, was significantly lower than that of adults. Given that red fox (Vulpes vulpes) numbers are low at these sites, this is possibly due to predation by feral cats (Felis catus), although this needs further investigation. Juvenile survival was also positively correlated with winter rainfall, possibly indicating that access to water is important during the drier winter months. In light of these observations, it is proposed that management of remaining warru colonies focus on cat control and consider providing access to free water during winter, as well as addressing landscape-scale threats such as wildfire and the spread of exotic plants.

Population dynamics, diet and aspects of the biology of feral cats and foxes in arid South Australia

2001 ◽  
Vol 28 (2) ◽  
pp. 195 ◽  
Author(s):  
John Read ◽  
Zoë Bowen
Keyword(s):  
Population Dynamics ◽  
South Australia ◽  
House Mice ◽  
Male And Female ◽  
Feral Cats ◽  
Wide Range ◽  
Bird Breeding

Average cat and fox densities at Roxby Downs, in northern South Australia, of 0.8 and 0.6 km–2 respectively, determined through spotlight counts over a 10-year period, probably considerably underestimate true densities. Peak rabbit populations coincided with high fox numbers, which probably suppressed cat densities. Cat abundance peaked when fox numbers were low but rabbit numbers were relatively high. When abundant, rabbits were the principal prey of both cats and foxes. Declines in rabbits numbers coincided with dramatic declines in fox numbers. By contrast, declines in cat populations were less marked, presumably because they could more effectively switch to hunting a wide range of native vertebrates. Sand-dwelling lizards, house mice and common small passerines were the most abundant non-rabbit, vertebrate prey taken by cats. We estimate that annual cat predation accounted for approximately 700 reptiles, 150 birds and 50 native mammals per square kilometre, whereas foxes consumed on average 290 reptiles per square kilometre and few native mammals and birds in the Roxby Downs region each year. Male cats and foxes were heavier than females. Feral cats typically weighed less than 4.0 kg, and cats weighing less than 2.5 kg typically preyed on more native vertebrates than did larger cats. Male and female cats were both typically tabby coloured, but a higher proportion of males were ginger in colour. Peak cat breeding coincided with rabbit and bird breeding and increased reptile activity during spring.

Sign in / Sign up

Export Citation Format

Share Document