Ontogeny of early diving and foraging behavior of northern fur seal (Callorhinus ursinus) pups from Bering Island,Russia

The ontogeny of diving and foraging behavior of northern fur seal pups from a stable population on Bering Island, Russia, was recorded with animal-borne instruments during their first few months at sea, a critical period during their first year at sea. Thirty-five pups were instrumented with satellite-linked time-depth recorders and stomach temperature pills. Diving occurred predominantly at night with deeper and longer dives as the pups matured. Mean dive depths were correlated with lunar illumination, whereas mean dive durations were also correlated with time of day and sex. Foraging success did not differ between sexes, and there was no relationship between meal size (as indicated by feeding event duration and minimum stomach temperature) and lunar illumination fraction or maximum foraging depth. Although most pups were able to successfully forage within 3 days of starting their migration, the number of feeding events recorded each day remained low (mean 1.6 events day^?1). There was no indication of an appreciable increase in meal size after the first 2 weeks of the migration despite an increase in dive frequency and depth. The results are consistent with observations that pups do not gain mass during their first year and emphasize the risk of starvation from infrequent foraging in cold water.     

Reinforcement of male mate preferences in sympatric killifish species Lucania goodei and Lucania parva

Reinforcement occurs when reduced hybrid fitness leads to the evolution of a stronger prezygotic isolation. Populations sympatric with closely related species, where hybridization occurs, are predicted to have stronger mate preferences than allopatric populations. The reinforcement of male mate preference is thought to be rarer than the reinforcement of female preference, but this inference may be biased by the lack of studies on male preference. We tested male mate preferences from sympatric and allopatric populations of two closely related species of killifish: Lucania goodei and Lucania parva. We found that sympatric males had greater preferences for conspecific females than allopatric males. Furthermore, conspecific preferences in allopatric populations were weakest when these populations were geographically distant (>50?km) from those of heterospecifics. Our data suggest that reinforcement has contributed to male conspecific preference and speciation in Lucania.     

Canada's Model Forests 20 years on: towards forest and community sustainability?

We review how Canadian Model Forests pursued forest and community sustainability over the course of two decades (1992–2012). Given its roots in the forest industry and forest science, Model Forest programming initially faced some challenges in pursuing the socio‐economic dimensions of sustainable forest management (SFM) in order to fulfil mandated community sustainability objectives. This was due, in part, to how objectives, stakeholders, and expertise were brought together to develop SFM. The programme helped to define sustainability and the SFM paradigm, advance forest science and social research, and bring together a mix of usually adversarial partners in the name of innovation. Ultimately, the termination of federal programming was linked to high‐level policy shifts, yet difficulty in delivering on the socio‐economic dimensions of SFM during a period of forest sector and community crisis was also a factor.     

Side effects of <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> var. kurstaki on the hymenopterous parasitic wasp <Emphasis Type="Italic">Trichogramma chilonis</Emphasis>

Most of the detrimental effects of using conventional insecticides to control crop pests are now well identified and are nowadays major arguments for replacing such compounds by the use of biological control agents. In this respect, the bacterium Bacillus thuringiensis var. kurstaki and Trichogramma (Hymenoptera: Trichogrammatidae) parasitic wasp species are both effective against lepidopterous pests and can actually be used concomitantly. In this work, we studied the potential side effects of B. thuringiensis var. kurstaki on Trichogramma chilonis females. We first evidenced an acute toxicity of B. thuringiensis on T. chilonis. Then, after ingestion of B. thuringiensis at sublethal doses, we focused on life history traits of T. chilonis such as longevity, reproductive success and the time spent on host eggs patches. The reproductive success of T. chilonis was not modified by B. thuringiensis while a significant effect was observed on longevity and the time spent on host eggs patches. The physiological and ecological meanings of the results obtained are discussed.     

Do sex-changing male snails use mate choice to get a jump on their “size advantage”?

Individuals of species that change sex from male to female may gain a “size advantage” from that sex change; that is, as males become larger, they become female, thus increasing their fecundity with their size. However, males could also gain an early and different reproductive size advantage by choosing large females as mates. While male preference for large females has been observed in many dioecious species, we know little about male size preference in sex-changing species. In choice experiments, we examined whether males of two congeneric species of marine sex-changing snails, Crepidula fornicata and C. convexa, chose large females over small ones as partners. We also used choice tests to see whether males of C. fornicata, a species whose members form long-term, multi-animal stacks, would choose two females in a stack over a single female. Surprisingly, males of neither species showed a preference for large females, in spite of the documented fecundity advantage associated with large female-size. Males of C. fornicata chose slightly, but not significantly, more single females than stacks, suggesting that neither number nor size drives mate choice in these animals. Key factors that may influence this lack of size preference include long association time, the likelihood of sperm competition, and the cost of extended mate search; it may also be that sex-change itself, the very factor that creates female-biased sexual size dimorphism in these species, prevents size preference, as males may gain sufficient reproductive advantage from eventually becoming large females themselves to offset any benefit of choosing large females.     

An Assessment of Road Impacts on Wildlife Populations in U.S. National Parks

Current United States National Park Service (NPS) management is challenged to balance visitor use with the environmental and social consequences of automobile use. Wildlife populations in national parks are increasingly vulnerable to road impacts. Other than isolated reports on the incidence of road-related mortality, there is little knowledge of how roads might affect wildlife populations throughout the national park system. Researchers at the Western Transportation Institute synthesized information obtained from a system-wide survey of resource managers to assess the magnitude of their concerns on the impacts of roads on park wildlife. The results characterize current conditions and help identify wildlife-transportation conflicts. A total of 196 national park management units (NPS units) were contacted and 106 responded to our questionnaire. Park resource managers responded that over half of the NPS units’ existing transportation systems were at or above capacity, with traffic volumes currently high or very high in one quarter of them and traffic expected to increase in the majority of units. Data is not generally collected systematically on road-related mortality to wildlife, yet nearly half of the respondents believed road-caused mortality significantly affected wildlife populations. Over one-half believed habitat fragmentation was affecting wildlife populations. Despite these expressed concerns, only 36% of the NPS units used some form of mitigation method to reduce road impacts on wildlife. Nearly half of the respondents expect that these impacts would only worsen in the next five years. Our results underscore the importance for a more systematic approach to address wildlife-roadway conflicts for a situation that is expected to increase in the next five to ten years.     

Isolation and fractionation of natural organic matter: evaluation of reverse osmosis performance and impact of fractionation parameters

Dissolved organic matter (DOM) from three surface waters was isolated using reverse osmosis (RO) and subsequently fractionated using resin adsorption chromatography (RAC). Efficacy of RO was evaluated by closing mass balances for dissolved organic carbon (DOC). RAC was evaluated by investigating the effect of column operational parameters (column capacity factor, k', and solute initial concentration, C0) on DOM fractionation and subsequent disinfection by-product formation. Efficacy of RO was dependent on both isolation conditions and source water characteristics. In general, RO more effectively isolated DOM in high specific ultraviolet absorbance (SUVA254) water than low SUVA254 water, and showed higher DOM recovery at ambient pH (approximately 7) than at low pH (approximately 4). The fractionation of the isolated DOM indicated that the relative amount of the hydrophobic fraction decreased with increasing k', thus affecting the overall distribution of DOM. However, the distribution of DOM fractions was not influenced by varying C0 up to 150 mg l(-1) at k' of 15. The effect of k' on the formation and speciation of trihalomethanes (THM) and haloacetic acids (HAA) was not significant up to k' of 30.     

Rendering Bio-inert Low-Density Polyethylene Amenable for Biodegradation via Fast High Throughput Reactive Extrusion Assisted Oxidation

Journal of Polymers and the Environment - An energy-efficient high throughput pre-treatment of low-density polyethylene (LDPE) using a fast, reactive extrusion (REX) assisted oxidation technique...