Stomach temperature records reveal nursing behaviour and transition to solid food consumption in an unweaned mammal, the harbour seal pup (Phoca vitulina)

Knowledge of milk transfer from mother to offspring and early solid food ingestions in mammals allows for a greater understanding of the factors affecting transition to nutritional independence and pre-weaning growth and survival. Yet studies monitoring suckling behaviour have often relied on visual observations, which might not accurately represent milk intake. We assessed the use of stomach temperature telemetry to monitor suckling and foraging behaviour in free-ranging harbour seal (Phoca vitulina) pups during lactation. Stomach temperature declines were analysed using principal component and cluster analyses, as well as trials using simulated stomachs resulting in a precise classification of stomach temperature drops into milk, seawater and solid food ingestions. Seawater and solid food ingestions represented on average 15.361.6% [0-40.0%] and 0.760.2% [0-13.0%], respectively, of individual ingestions. Overall, 63.7% of milk ingestions occurred while the pups were in the water, of which 13.9% were preceded by seawater ingestion. The average time between subsequent ingestions was significantly less for seawater than for milk ingestions. These results suggest that seawater ingestion might represent collateral ingestion during aquatic suckling attempts. Alternatively, as solid food ingestions (n = 19) were observed among 7 pups, seawater ingestion could result from missed prey capture attempts. This study shows that some harbour seals start ingesting prey while still being nursed, indicating that weaning occurs more gradually than previously thought in this species. Stomach temperature telemetry represents a promising method to study suckling behaviour in wild mammals and transition to nutritional independence in various endotherm species.

Interspecific and geographic variation in the diets of sympatric carnivores: dingoes/wild dogs and red foxes in south-eastern Australia

Dingoes/wild dogs (Canis dingo/familiaris) and red foxes (Vulpes vulpes) are widespread carnivores in southern Australia and are controlled to reduce predation on domestic livestock and native fauna. We used the occurrence of food items in 5875 dingo/wild dog scats and 11,569 fox scats to evaluate interspecific and geographic differences in the diets of these species within nine regions of Victoria, south-eastern Australia. The nine regions encompass a wide variety of ecosystems. Diet overlap between dingoes/wild dogs and foxes varied among regions, from low to near complete overlap. The diet of foxes was broader than dingoes/wild dogs in all but three regions, with the former usually containing more insects, reptiles and plant material. By contrast, dingoes/wild dogs more regularly consumed larger mammals, supporting the hypothesis that niche partitioning occurs on the basis of mammalian prey size. The key mammalian food items for dingoes/wild dogs across all regions were black wallaby (Wallabia bicolor), brushtail possum species (Trichosurus spp.), common wombat (Vombatus ursinus), sambar deer (Rusa unicolor), cattle (Bos taurus) and European rabbit (Oryctolagus cuniculus). The key mammalian food items for foxes across all regions were European rabbit, sheep (Ovis aries) and house mouse (Mus musculus). Foxes consumed 6.1 times the number of individuals of threatened Critical Weight Range native mammal species than did dingoes/wild dogs. The occurrence of intraguild predation was asymmetrical; dingoes/wild dogs consumed greater biomass of the smaller fox. The substantial geographic variation in diet indicates that dingoes/wild dogs and foxes alter their diet in accordance with changing food availability. We provide checklists of taxa recorded in the diets of dingoes/wild dogs and foxes as a resource for managers and researchers wishing to understand the potential impacts of policy and management decisions on dingoes/wild dogs, foxes and the food resources they interact with.

Copper in mammals: mechanisms of homeostasis and pathophysiology

The ability of mammals to tightly regulate systemic copper levels is vital for
health as demonstrated by the severity of the genetic copper deficiency and copper toxicity disorders, Menkes disease and Wilson disease, respectively. Analysis of these genetic disorders has led to a substantial increase in the understanding of the role of copper in health and disease. The isolation of the genes involved in these diseases and use of yeast mutants with altered copper and iron homeostasis has revealed a range of molecular mechanisms governing copper homeostasis. These mechanisms include regulation of cellular copper uptake and efflux and involve the use of chaperones for safe intracellular copper distribution. Here we provide an overview of the physiological role of copper and the molecular mechanisms
regulating systemic and cellular copper levels in mammals. Furthermore, we discuss the pathophysiological mechanisms and consequences of copper deficiency/overload in relation to disease.

Effect of Alpha-Linolenic acid on retnal function in mammals

The retinal function of several different species is compromised by a dietary deficiency of α-linolenic acid. A review of the literature revealed that diets containing less than O. 1 gIl OOg diet as α-linolenic acid could not sustain retinal docosahexaenoic acid levels over a prolonged period and that such diets were associated with a reduced response of the retina to light. In these studies the median α-linoleinic acid intake of control animals was 1.25g/100g diet. A study on the comparative ability of dietary α-linolenic acid and dietary docosahexaenoic acid to provide for retinal docosahexaenoic acid in the guinea pig found that α-linolenic acid was only approximately 10% as effective as docosahexaenoic acid in this regard.

A comparison of trace element concentrations in cultured and wild carp (Cyprinus carpio) of Lake Kasumigaura, Japan

The concentrations of 13 elements were determined in the muscle, liver, intestine, kidney, and gonads of cultured and wild carp caught at two sites in Lake Kasumigaura, Japan, between September 1994 and September 1995. Despite having a reputation for being heavily polluted, the carp were not heavily burdened with metals. Our results suggest that despite their dietary differences, the wild and cultured fish were accumulating and distributing metals in the same manner and that aquaculture practices are not increasing metal concentrations in these fish. Metal concentrations were lowest in muscle, and did not exceed established quality standards for fish. The differences in metal concentrations between cultivated and wild carp are negligible and should pose no health problems for consumers of either type of fish.

Molecular and cellular aspects of copper transport in developing mammals

Copper is an essential trace element that requires tightly regulated homeostatic mechanisms to ensure adequate supplies without any toxic effects because of the ability of the metal ion to catalyze the formation of free radicals. The Cu-ATPases, ATP7A and ATP7B, play an important role in the physiological regulation of copper. Adequate supplies of copper are particularly important in developing animals, and in humans this is illustrated by mutations of ATP7A that cause the copper deficiency condition Menkes disease, which is fatal in early childhood. In contrast, mutations in ATP7B result in the genetic toxicosis, Wilson disease. We propose that the physiological regulation of copper is accomplished mainly by the intracellular copper-regulated trafficking of the Cu-ATPases. This process allows the overall copper status in the body to be maintained when levels of copper in the diet alter. A study of the defects in mouse models of Menkes and Wilson diseases has demonstrated that both ATPases play an important role in supplying copper to the developing fetus and neonate

Spawning season, fecundity and proximate composition of the gonads of wild-caught blacklip abalone (Haliotis rubra) from Port Fairy waters, south eastern Australia

This study was based on wild-caught blacklip abalone Haliotis rubra L., from Port Fairy waters, south eastern Australia (142°15′E; 38°21′S), from July  1998 to November 1999, and was initiated to evaluate the spawning season and other aspects of its reproductive biology. The shell length and body weight of female and male abalone sampled ranged from 12.0 to 18.6 and 12 to 15 cm, and 137 to 529 and 148 to 585 g, respectively. The sex ratio did not vary significantly from 1:1 through the year. The gonadosomatic index (GSI) ranged from 3.0% to 8.4% in males, and 2.5% to 14.1% for females, and the highest GSI as well as the highest proportion of mature animals were recorded from September to October. During these months the hepatosomatic index (HSI) was low, and an inverse correlation between GSI and HSI (P < 0.05) was evident. Fecundity of blacklip abalone ranged from 1.09 to 7.5 million eggs for females of 12–14.5 cm in length, and 115–487 g in total body weight, respectively. The lipid content of the female gonad increased significantly from about July to November, and an opposite trend was observed for lipid content of the digestive gland. Seasonal changes in the protein and ash contents of the gonad and/or the digestive gland were not always significant.

Microsatellite loci for studies of wild and hatchery Australian Murray cod Maccullochella peelii peelii (Percichthyidae)

Murray cod is a species of conservation concern that is subject both to wild harvest and to aquaculture production. Six polymorphic microsatellite loci have been developed for this species, which will facilitate studies of wild-stock structure, will help the management of hatchery diversity, and will aid genetic improvement programmes. The markers exhibited nonindependence of genotypes between loci and deviations from Hardy–Weinberg expectations, although these most probably reflect practices at the hatchery from which the genotyped individuals were sourced.

Performance of intensively farmed Murray cod Maccullochella peelii peelii (Mitchell) fed newly formulated vs. currently used commercial diets, and a comparison of fillet composition of farmed and wild fish

Murray cod is a top-order carnivore with high culture potential. Currently, there are no commercial diets formulated specifically for Murray cod. In this study, results of two growth trials on Murray cod (80–83.5-g mean initial weight), conducted in commercial settings, using two laboratory-formulated diets (DU1 and DU2; 48.9% and 49.1% protein, and 16.9% and 16.1% lipid, respectively, on a dry matter basis), and two commercial diets, formulated for other species (salmon – CD/S and barramundi – CD/B) but used in Murray cod farming are presented. The two commercial diets had less protein (46.6% and 44.4%) but higher lipid (21.7% and 19.5%). The energy content of the feeds tested was similar (about 20–22 kJ g−1). The growth performance and feed utilization of Murray cod did not differ significantly amongst the diets, but the food conversion ratio and % protein efficiency ratio in fish fed the DU1 and DU2 diets were consistently better. There was significantly less carcass and muscle lipid deposition in fish fed with the latter diets. Of the fatty acids in muscle, the lowest amounts (in μg mg lipid−1) of n-3 (262.5±2.9), n-6 (39.8±0.9) and polyunsaturated fatty acid (PUFA) (302.3±3.8) were observed in fish fed CD/S, and the highest in fish fed DU2 and CD/B. Fatty acids 16:0 and 18:0, 18:1n-9 and 16:1n-7, and 22:6n-3, 20:5n-3, 22:5n-3 and 18:2n-6 were the dominant fatty acids amongst the saturates, monoenes and PUFA, respectively, and accounted for 80.8–88.7% of all identified fatty acids (23) in muscle of Murray cod. The study showed that Murray cod could be cultured successfully on a diet (DU2) containing 20% soybean meal without compromising growth and/or carcass quality. Differences in the proximate composition and fatty acid composition of muscle of wild and farmed Murray cod were observed, the most obvious being in the latter. Wild Murray cod had significantly less (P<0.05) saturates (192.6±1.84 vs. 266.3±3.51), monoenes (156.5±8.7 vs. 207.6±6.19), n-3 (145.2±5.24 vs. 261.8±3.2) but higher n-6 (144.3±2.73 vs. 48.3±1.38) in muscle (all values are in μg mg lipid−1) than in farmed fish. Wild fish also had a much lower n-3 to n-6 ratio (1.0±0.03 vs. 5.4±0.09).

Landscape characteristics associated with species richness and occurrence of small native mammals inhabiting a coastal heathland: a spatial modelling approach

In the coastal region of south-western Victoria, Australia, populations of native small mammal species are restricted to patches of suitable habitat in a highly fragmented landscape. The size and spatial arrangement of these patches is likely to influence both the occupancy and richness of species at a location. Geographic Information System (GIS)-based habitat models of the species richness of native small mammals, and individual species  occurrences, were developed to produce maps displaying the spatial  configuration of suitable habitat. Models were generated using either generalised linear Poisson regression (for species richness) or logistic regression (for species occurrences) with species richness or  presence/absence as the dependent variable and landscape variables, extracted from both GIS data layers and multi-spectral digital imagery, as the predictor variables. A multi-model inference approach based on the Akaike Information Criterion was used and the resulting model was applied in a GIS framework to extrapolate predicted richness/likelihood of occurrence across the entire area of the study. A negative association between species  richness and elevation, habitat complexity and sun index indicated that richness within the study area decreases with increasing altitude, vertical vegetation structure and exposure to solar radiation. Landform  characteristics were important (to varying degrees) in determining habitat occupancy for all of the species examined, while the influence of habitat complexity was important for only one of the species. Performance of all but one of the models generated using presence/absence data was high, as indicated by the area under the curve of a receiver-operating characteristic plot. The effective conservation of the small mammal species in the area of concern is likely to depend on management actions that promote the protection of the critical habitats identified in the models.

Heavy metal concentrations in wild and cultured blacklip abalone (haliotis rubra Leach) from southern Australian waters

The concentrations of 12 trace metals were assessed in wild and cultured specimens of blacklip abalone, Haliotis rubra, from each of two sites, Geelong and Port Fairy, in Victoria, Australia. Cadmium, copper, iron and zinc were quantified in the foot muscle of specimens from all four populations but the concentrations of aluminium, arsenic, beryllium, chromium, lead, manganese, nickel and vanadium were below the detection limits of the instrumental techniques employed. When similar sized specimens from each population were compared, the concentrations of each of the quantifiable metals varied according to location. The Geelong wild population had the highest or equal highest concentrations of each metal. Metal concentrations in the wild populations were usually greater than or equal to the concentrations in the corresponding cultured population. The concentrations of the regulated essential elements, copper and zinc, decreased with an increase in abalone length whereas the concentrations of iron, manganese and cadmium were independent of length. Metal concentrations in H. rubra from all sites complied with the Australian Food Code and other standards of food safety.

Capitalism run wild: Zizou Corder`s lion boy and Victor Kelleher`s dog boy

While capitalism has long made highly efficient ideological use of Darwin's 'survival of the fittest' principle to justify ruthless business practices, this appropriation of animal metaphor has taken on new and considerably more problematic resonances in the wake of globalization. At a time when the negative consequences of corporate greed are becoming more apparent, as inequalities widen and power is shifted beyond governments and their borders, there is a spate of children's novels that explicitly challenges this new world order.

What is the role of a-linolenic acid for mammals?

This review examines the data pertaining to an important and often underrated EFA, α-linolenic acid (ALA). It examines its sources, metabolism, and biological effects in various population studies, in vitro, animal, and human intervention studies. The main role of ALA was assumed to be as a precursor to the longer-chain n-3 PUFA, EPA and DHA, and particularly for supplying DHA for neural tissue. This paper reveals that the major metabolic route of ALA metabolism is β-oxidation. Furthermore, ALA accumulates in specific sites in the body of mammals (carcass, adipose, and skin), and only a small proportion of the fed ALA is converted to DHA. There is some evidence that ALA may be involved with skin and fur function. There is continuing debate regarding whether ALA has actions of its own in relation to the cardiovascular system and neural function. Cardiovascular disease and cancer are two of the major burdens of disease in the 21st century, and emerging evidence suggests that diets containing ALA are associated with reductions in total deaths and sudden cardiac death. There may be aspects of the action and, more importantly, the metabolism of ALA that need to be elucidated, and these will help us understand the biological effects of this compound better. Additionally, we must not forget that ALA is part of the whole diet and should be seen in this context, not in isolation.