Enhancement of reproductive success through mate choice in a social rock-wallaby, Petrogale assimilis (Macropodidae) as revealed by microsatellite markers

The reason why a female who is socially paired to one particular male seeks extra-pair copulations (EPCs) with others has important implications in life history models and to the study of behaviour. The Allied rock-wallaby, Petrogale assimilis, lives in spatially isolated colonies in tropical north Queensland, Australia. Extensive observations of a colony at Black Rock showed that intense behavioural bonding occurs between pairs of adult males and females; about two-thirds of males paired with one female, the remainder paired with two females simultaneously. Single-locus microsatellite profiling determined the paternity of 63 offspring from 21 females for which long-term behavioural data were available. One-third of the young were fathered by males which were not paired socially with the mother. The mating system was heterogeneous: (1) all offspring of 11 females were fathered by the mother's partner, (2) all young of 5 females were fathered by extra-pair males, and (3) only some of the young of 5 females were fathered by their regular consort. Analysis of individual longitudinal demographic records showed that females whose young were always fathered by their consort had higher reproductive success than those whose young were always fathered as a result of (EPCs). However, females with some offspring fathered by their regular consort and others via EPCs had the highest probability of raising young to independence. These females were significantly more likely to have an offspring fathered as a result of an EPC if their previous young had failed to survive to pouch emergence. These results are consistent with the hypothesis that females choose mates for their genetic quality. Comparison of the males with which these females sought EPCs and the regular consorts suggested that arm length rather than body weight or testes size was used as the index of genetic quality. Results from a second colony of rock-wallabies in which the reproductive rate was accelerated were also consistent with the genetic-quality hypothesis. These results imply that by choosing better-quality fathers irrespective of social pairing, females are able to maximise their overall lifetime reproductive success, and presumably, those of their offspring. Received: 8 June 1997 / Accepted after revision: 28 February 1998     

Elevated temperature elicits greater effects than decreased pH on the development, feeding and metabolism of northern shrimp (Pandalus borealis) larvae

Climate models predict that the average temperature in the North Sea could increase 3–5 °C and surface-waters pH could decrease 0.3–0.5 pH units by the end of this century. Consequently, we investigated the combined effect of decreased pH (control pH 8.1; decreased pH 7.6) and temperature (control 6.7 °C; elevated 9.5 °C) on the hatching timing and success, and the zoeal development, survival, feeding, respiration and growth (up to stage IV zoea) of the northern shrimp, Pandalus borealis. At elevated temperature, embryos hatched 3 days earlier, but experienced 2–4 % reduced survival. Larvae developed 9 days faster until stage IV zoea under elevated temperature and exhibited an increase in metabolic rates (ca 20 %) and an increase in feeding rates (ca 15–20 %). Decreased pH increased the development time, but only at the low temperature. We conclude that warming will likely exert a greater effect on shrimp larval development than ocean acidification manifesting itself as accelerated developmental rates with greater maintenance costs and decreased recruitment in terms of number and size.     

Chemical defence in ladybird beetles (Coccinellidae). I. Distribution of coccinelline and individual variation in defence in 7-spot ladybirds (Coccinella septempunctata)

Summary 7-spot ladybirds secrete alkaloid (coccinelline)-rich fluid (reflex blood) from leg joints as a defence mechanism against predators. A technique is described that enables the collection and accurate quantification of reflex blood produced, and the amount of coccinelline therein. Coccinelline was found distributed throughout the body, although concentrated in the reflex blood. Reflex blood was collected from a large set of beetles at several time points. Significant variation was found among beetles in the amount of reflex blood produced (for males and for females corrected for body weight) and the coccinelline concentration of the reflex blood. The results are discussed in relation to automimicry and the maintenance of variation through energy trade-offs. The relationships between tendency to aggregate, ability to reflex bleed and the possession of aposematic coloration are also considered.     

Influence of assumptions about household waste composition in waste management LCAs

This article takes a detailed look at an uncertainty factor in waste management LCA that has not been widely discussed previously, namely the uncertainty in waste composition. Waste composition is influenced by many factors; it can vary from year to year, seasonally, and with location, for example. The data publicly available at a municipal level can be highly aggregated and sometimes incomplete, and performing composition analysis is technically challenging. Uncertainty is therefore always present in waste composition. This article performs uncertainty analysis on a systematically modified waste composition using a constructed waste management system. In addition the environmental impacts of several waste management strategies are compared when applied to five different cities. We thus discuss the effect of uncertainty in both accounting LCA and comparative LCA. We found the waste composition to be important for the total environmental impact of the system, especially for the global warming, nutrient enrichment and human toxicity via water impact categories.     

Contrasting ecology of prograding coastal dunes on the northwest coast of Ireland

This paper examines the influence of dune morphological evolution on plant species diversity and composition on the Magheramore dune system, Donegal, north-west Ireland. It aims to demonstrate the need for understanding of local geomorphological factors and their affect on ecological processes for the enhanced conservation management of coastal dunes. Vegetation surveys and cluster analysis of species associations, in combination with GIS analysis focused on two prograding dune sites within the Magheramore system. Contrasting geomorphic evolution over similar timescales has imposed site-specific environmental conditions that have had a direct impact on the range of plant species communities present. Cluster analysis revealed 5 main species community types that defined specific dune habitats, the organisation of which is strongly influenced by geomorphic evolution. This study demonstrates the importance of geomorphic evolution and morphological heterogeneity in habitat and species diversity.     

Photolysis of pharmaceuticals and personal care products in the marine environment under simulated sunlight conditions: irradiation and identification

The photochemical fate of 16 pharmaceuticals and personal care products (PPCPs) found in the environment has been studied under controlled laboratory conditions applying a sunlight simulator. Aqueous samples containing PPCPs at environmentally relevant concentrations were extracted by solid-phase extraction (SPE) after irradiation. The exposed extracts were subsequently analysed by liquid chromatography combined with triple quadrupole mass spectrometry (HPLC-MS/MS) for studying the kinetics of photolytic transformations. Almost all exposed PPCPs appeared to react with a half-life time (τ _1/2) of less than 30 min. For ranitidine, sulfamethoxazole, diclofenac, warfarin, sulfamethoxazole and ciprofloxacin, τ_1/2 was found to be even less than 5 min. The structures of major photolysis products were determined using quadrupole-time-of-flight mass spectrometry (QToF) and spectroscopic data reported in the literature. For diclofenac, the transformation products carbazol-1-yl-acidic acid and 8-chloro-9H-carbazol-1-yl-acetic acid were identified based on the mass/charge ratio of protonated ions and their fragmentation pattern in negative electrospray ionization (ESI^?-QTOF). Irradiation of carbamazepine resulted in three known products: acridine, carbamazepine-10,11-epoxide, and 10,11-dihydro-10,11-dihydroxy-carbamazepine, whereas acetaminophen was photolytically transformed to 1-(2-amino-5 hydroxyphenyl) ethenone. These photochemical products were subsequently identified in seawater or fish samples collected at sites exposed to wastewater effluents on the Saudi Arabian coast of the Red Sea.     

Ecology and conservation of the rare annual Petrorhagia nanteuilii (Childing Pink) on the vegetated shingle spits of Pagham Harbour, West Sussex

Petrorhagia nanteuilii (Childing Pink), a nationally rare annual, exists at only one location in the UK on the vegetated shingle spits at Pagham Harbour, West Sussex. Primarily found in dry grassland habitats throughout Spain and Portugal, at present its only known threat in the UK is the invasive perennial, Centranthus ruber (Red Valerian); however for conservation of Petrorhagia nanteuilii to be sustainable, its presence at Pagham Harbour must be better understood. The aim of this study was therefore to investigate the local distribution and ecological associations of Petrorhagia nanteuilii in order to understand the relationships between Petrorhagia nanteuilii and the vegetated shingle communities and thereby inform their conservation. Field surveys of the shingle flora were undertaken in 2007 and 2011. Vegetation was sampled and the edaphic and physical environment was also investigated using TWINSPAN, multivariate analyses and GIS. The results of the study show that Petrorhagia nanteuilii has little association with the true vegetated shingle communities on the shingle spits. They also reveal that in recent years the species has spread rapidly across parts of the site due to a number of adaptations aiding its survival and recent shifts in conservation management that have influenced spit morphology. The ecological disconnection that exists between Petrorhagia nanteuilii and the true shingle communities means it is unlikely that management strategies will be conflicting. The study concludes that conservation of both is feasible, however for management to be sustainable, both short-term and long-term strategies must be considered.