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.

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.

scholarly journals Interactions between a Top Order Predator and Exotic Mesopredators in the Australian Rangelands

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Katherine E. Moseby ◽  
Heather Neilly ◽  
John L. Read ◽  
Helen A. Crisp
Keyword(s):  
Intraguild Predation ◽  
Prey Species ◽  
Red Fox ◽  
Interference Competition ◽  
South Australia ◽  
Mortality Rates ◽  
Net Benefit ◽  
Male And Female ◽  
Dominant Mechanism ◽  
Feral Cats

An increase in mesopredators caused by the removal of top-order predators can have significant implications for threatened wildlife. Recent evidence suggests that Australia’s top-order predator, the dingo, may suppress the introduced cat and red fox. We tested this relationship by reintroducing 7 foxes and 6 feral cats into a 37 km2fenced paddock in arid South Australia inhabited by a male and female dingo. GPS datalogger collars recorded locations of all experimental animals every 2 hours. Interactions between species, mortality rates, and postmortems were used to determine the mechanisms of any suppression. Dingoes killed all 7 foxes within 17 days of their introduction and no pre-death interactions were recorded. All 6 feral cats died between 20 and 103 days after release and dingoes were implicated in the deaths of at least 3 cats. Dingoes typically stayed with fox and cat carcasses for several hours after death and/or returned several times in ensuing days. There was no evidence of intraguild predation, interference competition was the dominant mechanism of suppression. Our results support anecdotal evidence that dingoes may suppress exotic mesopredators, particularly foxes. We outline further research required to determine if this suppression translates into a net benefit for threatened prey species.

scholarly journals Developing Equations for Converting Digestible Energy to Metabolizable Energy for Korean Hanwoo Beef Cattle

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1696
Author(s):  
Ridha Ibidhi ◽  
Rajaraman Bharanidharan ◽  
Jong-Geun Kim ◽  
Woo-Hyeong Hong ◽  
In-Sik Nam ◽  
...  
Keyword(s):  
Linear Regression ◽  
Beef Cattle ◽  
Strong Relationship ◽  
Dietary Factors ◽  
Metabolizable Energy ◽  
Coefficient Of Determination ◽  
Simple Linear Regression ◽  
Male And Female ◽  
Digestible Energy ◽  
Wide Range

This study was performed to update and generate prediction equations for converting digestible energy (DE) to metabolizable energy (ME) for Korean Hanwoo beef cattle, taking into consideration the gender (male and female) and body weights (BW above and below 350 kg) of the animals. The data consisted of 141 measurements from respiratory chambers with a wide range of diets and energy intake levels. A simple linear regression of the overall unadjusted data suggested a strong relationship between the DE and ME (Mcal/kg DM): ME = 0.8722 × DE + 0.0016 (coefficient of determination (R2) = 0.946, root mean square error (RMSE) = 0.107, p < 0.001 for intercept and slope). Mixed-model regression analyses to adjust for the effects of the experiment from which the data were obtained similarly showed a strong linear relationship between the DE and ME (Mcal/kg of DM): ME = 0.9215 × DE − 0.1434 (R2 = 0.999, RMSE = 0.004, p < 0.001 for the intercept and slope). The DE was strongly related to the ME for both genders: ME = 0.8621 × DE + 0.0808 (R2 = 0.9600, RMSE = 0.083, p < 0.001 for the intercept and slope) and ME = 0.7785 × DE + 0.1546 (R2 = 0.971, RMSE = 0.070, p < 0.001 for the intercept and slope) for male and female Hanwoo cattle, respectively. By BW, the simple linear regression similarly showed a strong relationship between the DE and ME for Hanwoo above and below 350 kg BW: ME = 0.9833 × DE − 0.2760 (R2 = 0.991, RMSE = 0.055, p < 0.001 for the intercept and slope) and ME = 0.72975 × DE + 0.38744 (R2 = 0.913, RMSE = 0.100, p < 0.001 for the intercept and slope), respectively. A multiple regression using the DE and dietary factors as independent variables did not improve the accuracy of the ME prediction (ME = 1.149 × DE − 0.045 × crude protein + 0.011 × neutral detergent fibre − 0.027 × acid detergent fibre + 0.683).

scholarly journals Insights into mammalian biology from the wild house mouse Mus musculus

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Megan Phifer-Rixey ◽  
Michael W Nachman
Keyword(s):  
House Mouse ◽  
Mus Musculus ◽  
Genetic Model ◽  
Inbred Strains ◽  
Mendelian Inheritance ◽  
Model Organisms ◽  
House Mice ◽  
Small Subset ◽  
Wild Mice ◽  
Wide Range

The house mouse, Mus musculus, was established in the early 1900s as one of the first genetic model organisms owing to its short generation time, comparatively large litters, ease of husbandry, and visible phenotypic variants. For these reasons and because they are mammals, house mice are well suited to serve as models for human phenotypes and disease. House mice in the wild consist of at least three distinct subspecies and harbor extensive genetic and phenotypic variation both within and between these subspecies. Wild mice have been used to study a wide range of biological processes, including immunity, cancer, male sterility, adaptive evolution, and non-Mendelian inheritance. Despite the extensive variation that exists among wild mice, classical laboratory strains are derived from a limited set of founders and thus contain only a small subset of this variation. Continued efforts to study wild house mice and to create new inbred strains from wild populations have the potential to strengthen house mice as a model system.

scholarly journals A Model for Analysing the Collective Dynamic Behaviour and Characterising the Exploitation of Population-Based Algorithms

2014 ◽  
Vol 22 (1) ◽  
pp. 159-188 ◽  
Author(s):  
Mikdam Turkey ◽  
Riccardo Poli
Keyword(s):  
Population Dynamics ◽  
Dynamic Behaviour ◽  
Fitness Landscape ◽  
Population Based ◽  
Levels Of Abstraction ◽  
Collective Dynamic ◽  
Model Studies ◽  
Proposed Model ◽  
Wide Range ◽  
Multiple Levels

Several previous studies have focused on modelling and analysing the collective dynamic behaviour of population-based algorithms. However, an empirical approach for identifying and characterising such a behaviour is surprisingly lacking. In this paper, we present a new model to capture this collective behaviour, and to extract and quantify features associated with it. The proposed model studies the topological distribution of an algorithm's activity from both a genotypic and a phenotypic perspective, and represents population dynamics using multiple levels of abstraction. The model can have different instantiations. Here it has been implemented using a modified version of self-organising maps. These are used to represent and track the population motion in the fitness landscape as the algorithm operates on solving a problem. Based on this model, we developed a set of features that characterise the population's collective dynamic behaviour. By analysing them and revealing their dependency on fitness distributions, we were then able to define an indicator of the exploitation behaviour of an algorithm. This is an entropy-based measure that assesses the dependency on fitness distributions of different features of population dynamics. To test the proposed measures, evolutionary algorithms with different crossover operators, selection pressure levels and population handling techniques have been examined, which lead populations to exhibit a wide range of exploitation-exploration behaviours.

scholarly journals Developmental exposure to silver nanoparticles leads to long term gut dysbiosis and neurobehavioral alterations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhen Lyu ◽  
Shreya Ghoshdastidar ◽  
Karamkolly R. Rekha ◽  
Dhananjay Suresh ◽  
Jiude Mao ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Body Fat ◽  
Repetitive Behaviors ◽  
Developmental Exposure ◽  
Male And Female ◽  
Female Mice ◽  
Gut Dysbiosis ◽  
Study Results ◽  
Wide Range

AbstractDue to their antimicrobial properties, silver nanoparticles (AgNPs) are used in a wide range of consumer products that includes topical wound dressings, coatings for biomedical devices, and food-packaging to extend the shelf-life. Despite their beneficial antimicrobial effects, developmental exposure to such AgNPs may lead to gut dysbiosis and long-term health consequences in exposed offspring. AgNPs can cross the placenta and blood–brain-barrier to translocate in the brain of offspring. The underlying hypothesis tested in the current study was that developmental exposure of male and female mice to AgNPs disrupts the microbiome–gut–brain axis. To examine for such effects, C57BL6 female mice were exposed orally to AgNPs at a dose of 3 mg/kg BW or vehicle control 2 weeks prior to breeding and throughout gestation. Male and female offspring were tested in various mazes that measure different behavioral domains, and the gut microbial profiles were surveyed from 30 through 120 days of age. Our study results suggest that developmental exposure results in increased likelihood of engaging in repetitive behaviors and reductions in resident microglial cells. Echo-MRI results indicate increased body fat in offspring exposed to AgNPs exhibit. Coprobacillus spp., Mucispirillum spp., and Bifidobacterium spp. were reduced, while Prevotella spp., Bacillus spp., Planococcaceae, Staphylococcus spp., Enterococcus spp., and Ruminococcus spp. were increased in those developmentally exposed to NPs. These bacterial changes were linked to behavioral and metabolic alterations. In conclusion, developmental exposure of AgNPs results in long term gut dysbiosis, body fat increase and neurobehavioral alterations in offspring.

Influence of operating conditions on population dynamics in nitrifying biofilms

1999 ◽  
Vol 39 (7) ◽  
pp. 5-11 ◽  
Author(s):  
Valentina Lazarova ◽  
Danièle Bellahcen ◽  
Jacques Manem ◽  
David A. Stahl ◽  
Bruce E. Rittmann
Keyword(s):  
Population Dynamics ◽  
Ammonia Oxidation ◽  
Biofilm Reactor ◽  
Operating Conditions ◽  
Stable Operation ◽  
N Removal ◽  
Wide Range ◽  
Total Nitrogen Removal ◽  
Nitrite Oxidizers

TURBO N® is a circulating-bed biofilm reactor that provides stable operation and high N removal for a wide range of N and BOD loadings. This paper describes the influence of operating conditions on biofilm composition and population dynamics when the TURBO N® is operated to achieve tertiary nitrification, simultaneous carbon and ammonia oxidation and total nitrogen removal when coupled with a pre-denitrification fixed floating bed reactor. In situ specific nitrification rates and respiration tests showed that ammonium and nitrite oxidizers became less active in the biofilm once oxidation of influent BOD became important. Analyses of community structure with oligonucleotide probes targeted to the 16S rRNA showed the same general trends for nitrifiers, but also suggested shifts in the makeup of the ammonium and nitrite oxidizers that could not be detected with respirometry or specific nitrification rates.

scholarly journals Differential Progression of Motor Dysfunction Between Male and Female Fragile X Premutation Carriers Reveals Novel Aspects of Sex-Specific Neural Involvement

2021 ◽  
Vol 7 ◽  
Author(s):  
Danuta Z. Loesch ◽  
Flora Tassone ◽  
Anna Atkinson ◽  
Paige Stimpson ◽  
Nicholas Trost ◽  
...  
Keyword(s):  
Sex Differences ◽  
White Matter ◽  
White Matter Hyperintensities ◽  
Fragile X ◽  
Cognitive Measures ◽  
Cross Sectional ◽  
Male And Female ◽  
Fragile X Premutation ◽  
Wide Range ◽  
Female Carriers

Expansions of the CGG repeat in the non-coding segment of the FMR1 X-linked gene are associated with a variety of phenotypic changes. Large expansions (&gt;200 repeats), which cause a severe neurodevelopmental disorder, the fragile x syndrome (FXS), are transmitted from the mothers carrying smaller, unstable expansions ranging from 55 to 200 repeats, termed the fragile X premutation. Female carriers of this premutation may themselves experience a wide range of clinical problems throughout their lifespan, the most severe being the late onset neurodegenerative condition called “Fragile X-Associated Tremor Ataxia Syndrome” (FXTAS), occurring between 8 and 16% of these carriers. Male premutation carriers, although they do not transmit expanded alleles to their daughters, have a much higher risk (40–50%) of developing FXTAS. Although this disorder is more prevalent and severe in male than female carriers, specific sex differences in clinical manifestations and progress of the FXTAS spectrum have been poorly documented. Here we compare the pattern and rate of progression (per year) in three motor scales including tremor/ataxia (ICARS), tremor (Clinical Tremor Rating scale, CRST), and parkinsonism (UPDRS), and in several cognitive and psychiatric tests scores, between 13 female and 9 male carriers initially having at least one of the motor scores ≥10. Moreover, we document the differences in each of the clinical and cognitive measures between the cross-sectional samples of 21 female and 24 male premutation carriers of comparable ages with FXTAS spectrum disorder (FSD), that is, who manifest one or more features of FXTAS. The results of progression assessment showed that it was more than twice the rate in male than in female carriers for the ICARS-both gait ataxia and kinetic tremor domains and twice as high in males on the CRST scale. In contrast, sex difference was negligible for the rate of progress in UPDRS, and all the cognitive measures. The overall psychiatric pathology score (SCL-90), as well as Anxiety and Obsessive/Compulsive domain scores, showed a significant increase only in the female sample. The pattern of sex differences for progression in motor scores was consistent with the results of comparison between larger, cross-sectional samples of male and female carriers affected with the FSD. These results were in concert with sex-specific distribution of MRI T2 white matter hyperintensities: all males, but no females, showed the middle cerebellar peduncle white matter hyperintensities (MCP sign), although the distribution and severity of these hyperintensities in the other brain regions were not dissimilar between the two sexes. In conclusion, the magnitude and specific pattern of sex differences in manifestations and progression of clinically recorded changes in motor performance and MRI lesion distribution support, on clinical grounds, the possibility of certain sex-limited factor(s) which, beyond the predictable effect of the second, normal FMR1 alleles in female premutation carriers, may have neuroprotective effects, specifically concerning the cerebellar circuitry.

scholarly journals Effects of transverse relationships between maxillary arch, mouth, and face on smile esthetics

2015 ◽  
Vol 86 (1) ◽  
pp. 135-141 ◽  
Author(s):  
Ke Zhang ◽  
Lan Huang ◽  
Lin Yang ◽  
Li Xu ◽  
Chaoran Xue ◽  
...  
Keyword(s):  
Young Female ◽  
Male And Female ◽  
Facial Region ◽  
Face Width ◽  
Wide Range ◽  
Left And Right ◽  
Smile Esthetics ◽  
Maxillary Arch ◽  
The Ideal

ABSTRACTObjective: To identify the ideal ratios between the widths of the maxillary arch, mouth, and face, respectively, and to determine the range of acceptable esthetic variations based on these ideal ratios.Materials and Methods: A photograph of a young female with a harmonious smile was selected and digitally altered to produce two sets of images. The first image showed an altered intercanine width, while the second one showed an altered oral fissure breadth. These alterations were independently rated by judges, including 23 orthodontists and 30 undergraduates. The Mann-Whitney U-test was used to compare the scores given by male and female judges and those given by professional and nonprofessional judges.Results: The following ideal transverse ratios were determined: intercanine width/oral fissure breadth, 0.638; oral fissure breadth/interparopia width: the distance between left and right paropia, 0.617; and intercanine width/face width at the level of the labial commissures, 0.300. A range of −10% to +10% was proposed as the thresholds of esthetic smile evaluations. It was shown that gender of the raters had no effect on the rating of photographs, nor were there any statistically significant differences between the professional and nonprofessional judges’ ratings.Conclusions: Balanced transverse relationships in the facial region are important for smile esthetics, and there is a wide range of esthetically acceptable variations in the transverse relationships between the maxillary arch, mouth, and face.

scholarly journals The body-size dependence of mutual interference

2014 ◽  
Vol 10 (6) ◽  
pp. 20140261 ◽  
Author(s):  
John P. DeLong
Keyword(s):  
Population Dynamics ◽  
Body Size ◽  
Size Dependence ◽  
Empirical Support ◽  
Mutual Interference ◽  
The Body ◽  
Wide Range ◽  
Stabilizing Effect ◽  
Body Sizes ◽  
Size Scales

The parameters that drive population dynamics typically show a relationship with body size. By contrast, there is no theoretical or empirical support for a body-size dependence of mutual interference, which links foraging rates to consumer density. Here, I develop a model to predict that interference may be positively or negatively related to body size depending on how resource body size scales with consumer body size. Over a wide range of body sizes, however, the model predicts that interference will be body-size independent. This prediction was supported by a new dataset on interference and consumer body size. The stabilizing effect of intermediate interference therefore appears to be roughly constant across size, while the effect of body size on population dynamics is mediated through other parameters.

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