Seasonal changes in the diet of the long-nosed bandicoot (Perameles nasuta) assessed by analysis of faecal scats and of stable isotopes in blood

The diet of long-nosed bandicoots (Perameles nasuta) on the central coast of New South Wales, Australia, was examined over two summers and two winters using a combination of faecal scat analysis for food fragments and stable isotope analysis (ratios of ¹³C/¹²C and ¹⁵N/¹⁴N) of blood. Isotope ratios in blood overlapped most strongly with those in invertebrate prey, and varied much less between seasons than did those in most dietary items, suggesting that the assimilated diet of long-nosed bandicoots is dominated by invertebrates throughout the year. Invertebrate remains dominated collected faeces in both seasons, even though the availability of invertebrate prey was higher in summer. Thus both techniques indicated that long-nosed bandicoots were primarily insectivorous year-round. Faecal scat analysis indicated that invertebrate eggs were more abundant in summer than winter. At a finer scale, spiders, orthopterans, lepidopteran larvae, ants, leaf material (non-grass monocot) and seeds were more abundant in summer, while cicada larvae, roots, fungi, grass leaves and Acacia bract (small modified leaves appearing as scales) were more abundant in winter. Subterranean foods (cicada larvae, plant roots and hypogeous fungi) were more abundant in winter and more abundant in the diet of males than of either lactating or non-lactating females.

Stable isotopes reveal inter-annual and inter-individual variation in the diet of female Australian fur seals

Understanding the temporal and spatial variation of foraging habits of apex predators is central to understanding their role in marine ecosystems and how their populations may respond to environmental variability. In the present study, stable isotope analysis (C and N) of blood was used to investigate inter-individual and inter-annual differences in the diet of adult female Australian fur seals Arctocephalus pusillus doriferus. Positive correlations were observed between red cell and plasma values for δ¹³C and δ¹⁵N (r² = 0.47 and r² = 0.66, respectively, p < 0.001 in both cases), suggesting relatively consistent individual prey choices over 3 or 4 foraging trips. Mean δ¹⁵N values (12.8 to 17.5%) confirm the species occupies the highest marine trophic niche in the region. A significant decrease in plasma δ¹⁵N values, corresponding to two-thirds of a trophic level (ca. 2%), was observed between the 1998 to 2000 and 2003 to 2005 sampling periods. This was associated with a significant decrease in adult female body condition and is consistent with a decline, previously documented by faecal analysis, of the proportion of red cod Pseudophysis bachus, barracouta Thyrsites atun and Gould's squid Nototodarus gouldi in the diet and an increase in redbait Emmelichthys nitidus. While substantial variation in δ¹⁵N was observed within each age cohort, a significant decrease was observed with age, suggesting individual specialisation for particular prey types is evident early in adulthood, but that its composition changes as females age. In addition, generalized linear models indicated body mass had a negative influence on δ¹⁵N, which may reflect larger total body oxygen stores, facilitating individuals hunting cryptic prey of lower trophic level (e.g. octopus) on the sea floor.

Modeling and defense against propagation of worms in networks

Worms are widely believed to be one of the most serious challenges in network security research. In order to prevent worms from propagating, we present a microcosmic model, which can benefit the security industry by allowing them to save significant money in the deployment of their security patching schemes.

Association between maternal education and diet of children at 9 months is partially explained by mothers' diet

Infants of mothers of low educational background display consistently poorer outcomes, including suboptimal weaning diets. Less is known about the different causal pathways that relate maternal education to infants' diet. The present study aimed to test the hypothesis that the relationship between maternal education and infants' diet is mediated by mothers' diet. The analyses included 421 mother–infant pairs from the Melbourne Infant Feeding Activity and Nutrition Trial (InFANT) Program. Dietary intakes were collected from mothers when infants were aged 3 months, using a validated food frequency questionnaire relating to the past year, and in infants aged 9 months using 3 × 24-h recalls. Principal component analysis was used to derive dietary pattern scores, based on frequencies of 55 food groups in mothers, and intakes of 23 food groups in infants. Associations were assessed with multivariable linear regression. We tested the product ‘ab’ to address the mediation hypothesis, where ‘a’ refers to the relationship between the predictor variable (education) and the mediator variable (mothers' diet), and ‘b’ refers to the association between the mediator variable and the outcome variable (infants' diet), controlling for the predictor variable. Maternal scores on the ‘Fruit and vegetables’ dietary pattern partially mediated the relationships between maternal education and two infant dietary patterns, namely ‘Balanced weaning diet’ [ab = 0.11; 95% confidence interval (CI): 0.04; 0.18] and ‘Formula’ (ab = −0.08; 95%CI: −0.15; −0.02). These findings suggest that targeting pregnant mothers of low education level with the aim of improving their own diet may also promote better weaning diets in their infants.

Assessing the use of milk fatty acids to infer the diet of the Australian sea lion (Neophoca cinerea)

Information on the diet of threatened species is important in devising appropriate management plans to ensure their conservation. The Australian sea lion (Neophoca cinerea) is Australia’s only endemic and globally one of the least numerous pinniped species. However, dietary information is currently limited because of the difficulty in using traditional methods (identification of prey hard parts from scats, regurgitates and stomach samples) to reliably provide dietary information. The present study assessed the use of fatty acid (FA) analysis to infer diet using milk samples collected from 11 satellite tracked Australian sea lions from Olive Island, South Australia. Satellite tracking revealed that females foraged in two distinct regions; ‘inshore’ regions characterised by shallow bathymetry (10.7 ± 4.8 m) and ‘offshore’ regions characterised by comparatively deep bathymetry (60.5 ± 13.4 m). Milk FA analysis indicated significant differences in the FA composition between females that foraged inshore compared with those that foraged offshore. The greatest differences in relative levels of individual FAs between the inshore and offshore groups were for 22 : 6n-3 (6.5 ± 1.2% compared with 16.5 ± 1.9% respectively), 20 : 4n-6 (6.1 ± 0.7 compared with 2.5 ± 0.7 respectively) and 22 : 4n-6 (2.4 ± 0.2% compared with 0.8 ± 0.2% respectively). Using discriminant scores, crustacean, cephalopod, fish and shark-dominated diets were differentiated. The discriminant scores from Australian sea lions that foraged inshore indicated a mixed fish and shark diet, whereas discriminant scores from Australian sea lions that foraged offshore indicated a fish-dominated diet, although results must be interpreted with caution due to the assumptions associated with the prey FA dataset. FA analysis in combination with satellite tracking proved to be a powerful tool for assessing broad-scale spatial dietary patterns.

Timing of breeding and diet of the Black-faced cormorant Phalacrocorax fuscescens

Previous anecdotal reports have suggested that Black-faced Cormorant Phalacrocorax fuscescens breeds only in winter in southeastern Australia, but detailed reports confirming this are lacking. Here we examine the timing of breeding in Black-faced Cormorants at Notch Island in northern Bass Strait in 2006. Peak laying occurred during winter (ca 26 July). The diet of Black-faced Cormorants was predominantly fish (97% of identified prey) and varied between breeding and post-breeding periods. Black-faced Cormorants consumed a total of 14 different species with four species having a frequency of occurrence in the diet of ?5% during the breeding season and six species during the post-breeding period. We provide data for the first time on the chronology of breeding of Black-faced Cormorants in one year and give a preliminary description of their diet based on pellet analyses. We propose that late winter breeding may be a strategy to avoid the high ambient temperatures in northern Bass Strait during summer, the associated higher thermoregulatory costs for adults and the increased mortality for chicks.

Distribution, extent of inter-annual variability and diet of the bloom-forming jellyfish Rhizostoma in European waters

Jellyfish (Cnidaria: Scyphozoa) are increasingly thought to play a number of important ecosystem roles, but often fundamental knowledge of their distribution, seasonality and inter-annual variability is lacking. Bloom forming species, due to their high densities, can have particularly intense trophic and socio-economic impacts. In northern Europe it is known that one particularly large (up to 30 kg wet weight) bloom forming jellyfish is Rhizostoma spp. Given the potential importance, we set out to review all known records from peer-reviewed and broader public literature of the jellyfish R. octopus (Linnaeus) and R. pulmo (Macri) (Scyphozoa: Rhizostomae) across western Europe. These data revealed distinct hotspots where regular Rhizostoma spp. aggregations appeared to form, with other sites characterized by occasional abundances and a widespread distribution of infrequent observations. Surveys of known R. octopus hotspots around the Irish Sea also revealed marked inter-annual variation with particularly high abundances forming during 2003. The location of such consistent aggregations and inter-annual variances are discussed in relation to physical, climatic and dietary variations.

The breeding diet of Wedge-tailed Eagles Aquila audax in the absence of rabbits: Kangaroo Island, South Australia

Rabbits form a signifi cant component of the diet of the Wedge-tailed Eagle Aquila audax, particularly in temperate mainland Australia. The breeding-season diet of this eagle species was studied on Kangaroo Island, South Australia - a large island lacking rabbits. Wedge-tailed Eagles at three nest sites consumed mostly mammals (67% of prey individuals; 95% biomass; fi ve species), but also birds (33% of prey individuals; 5% biomass; fi ve species). Although roadkill is abundant on Kangaroo Island, further study is required to determine its relative infl uence in the diet of Wedge-tailed Eagles in this region.

Opening up a can of worms: how do decision-makers decide when witnesses are telling the truth?

Correctly determining witness credibility is integral to a fair trial. Assessments of credibility made by the triers of fact are made, amongst other things, by reference to behavioural stereotypes that are commonly thought to be associated with lying and truth-telling. These stereotypes are worthless but pervasive. In this study, potential jurors were given information such as would be given by way of judicial direction and/or expert testimony on those behavioural indicia that are useful in detecting deception. Major changes in perceptions of what does and does not work were found. This has significant implications for the conduct of criminal trials. Recommendations are presented which, it is argued, can be of real, practical, assistance in enabling decision-makers to assess the credibility of witnesses. © 2013 The Australian and New Zealand Association of Psychiatry, Psychology and Law.

The diet of Pacific gulls (Larus pacificus) breeding at Seal Island in northern Bass Strait

The endemic Pacific gull (Larus pacificus) is Australia's largest larid, and though little is currently known of its foraging ecology, its size and wide distribution suggest that it may play an important role within the marine environment. In the present study, regurgitate pellets collected from Seal Island in northern Bass Strait were used to compare intra- and interannual trends in diet composition. The main taxa identified in pellets were the common diving-petrel (Pelecanoides urinatrix), leatherjacket species (Family Monacanthidae), short-tailed shearwater (Puffinus tenuirostris) and mirror bush (Coprosma repens). Analysis of similarity (ANOSIM) identified no significant differences in numerical abundance of the dominant prey species between years, suggesting that the prey base in this region is temporally consistent or that the gulls consume low enough numbers to be unaffected by fluctuation in prey populations. Diving-petrels were consumed in consistently high numbers, suggesting the gulls may be an important predator of this species, or that the gulls are particularly skilled at foraging for them. © CSIRO 2014.