Environmental conditions and their impact on immunocompetence and pathogen susceptibility of the Caribbean termite Nasutitermes acajutlae

1. Little is known about interactions between environmental conditions surrounding insects and their immune responses. 2. The environment in and around termite colonies, including temperature, relative humidity, soil pH, and light was analysed using principal components analysis (PCA). 3. The relationship between these abiotic parameters and two aspects of termite immunity (phenoloxidase activity and lipid content) was examined in field‐caught workers of Nasutitermes acajutlae Holmgren. Finally, termites from warm/dry and cool/moist habitats were exposed to Metarhizium anisopliae to determine their susceptibility to mycosis. 4. PCA indicated that environmental components external to the nest [ambient temperature, ambient relative humidity (RH), soil temperature and light] comprised the majority (PC1 = 37.5%) of variation. Internal variables (nest temperature and RH) and nest volume accounted for 19.6% (PC2) of the variation with pH comprising 12.9% (PC3). 5. AIC and regression models suggested that ambient temperature was most strongly and positively associated with immune variables and that relative humidity may also play a role. Termites from warm/dry colonies were less susceptible to M. anisopliae than termites from cool/moist colonies. 6. Thus, termites nesting in warmer habitats may exhibit increased immune‐related measures and reduced susceptibility to mycosis compared with termites from cooler habitats.     

Fraternity and Terror: The Organization of Violence in Everyday Life

This paper was inspired by participant observation in the Coalfields towns of the Hunter Valley in New South Wales. It is an attempt to demonstrate the significance of violence in the political practice of coal-miners. This significance has been overlooked in the recent enthusiasm for studies of ‘dominant ideologies’. Beyond this, the paper is an attempt to theorize the role of routine violence in the formation, maintenance and dissolution of social groups. The processes of group formation are an important subject for any theory of political practice.     

Factors influencing the distribution of medium‐sized ground‐dwelling mammals in southeastern mainland Australia

Abstract The forage diggings of medium‐sized ground‐dwelling mammals (bandicoots and potoroos) were recorded over two seasons across 136 forested study sites, representing a stratified sample of the climatic, geological and topographic features of far south‐eastern mainland Australia. Diggings, presumably left by bandicoots, were recorded at a total of 42 sites, and those of potoroos at 27 sites. Statistical models were developed for the occurrence of these diggings, based on environmental attributes measured for each site. At a landscape scale, mean minimum temperature of the coldest month was an important explanatory variable for both groups of animals, with likelihood of their occurrence increasing with increasing temperature during that period. More locally, soil fertility and time since last fire also influenced the occurrence of bandicoot and potoroo diggings, while density of ground cover was additionally important in explaining the occurrence of bandicoot diggings. Bandicoot and potoroo diggings were more likely to occur with decreasing soil fertility and increasing time since fire, while occurrence of bandicoot diggings also increased with increasing density of ground cover. The possible management implications of our findings for conservation of medium‐sized ground‐dwelling mammals in multiple‐use forests are discussed.     

Sex-Age Selectivity and Correlates of Capture for Winter-Trapped White-Tailed Deer

ANDREW J. TYRE⁷ ABSTRACT Despite the common use of Clover traps to capture white-tailed deer (Odocoileus virginianus), little published information exists quantifying trap success, trap selectivity (sex-age selection), or weather correlates of trap success. We quantified these relationships using white-tailed deer data from 3 study sites in the Lower Peninsula of Michigan, USA, during winters 2001–2007. We captured 610 deer in 8,569 trap-nights; pooled capture success was 0.07 deer/trap-night, although site-year success varied from 0.021 to 0.086. We compared sex-age classes (fawn [pooled by sex], ad M, ad F) captured with sex-age classes estimated to be available on each study site during each capture season. We used generalized linear mixed modeling to construct 19 a priori models to describe probability of capture success as a function of weather covariates (daily min. temp [° C], daily snowfall [cm], daily snow depth [cm]), Julian day, site, and year. General selection patterns included fawns captured more than expected and adult males captured less than expected; adult females were generally neutrally selected. The quasi-Akaike's Information Criterion best model within our set was described by the global model without Julian day and contained all 3 weather covariates and site-year effects. Our model provided some evidence that as daily snow depth increased, probability of capture increased; the positive effect of daily snowfall on capture probability was dependent on decreasing daily minimum temperature. Our results may be used to increase efficacy of deer capture programs by researchers and managers through informed decision-making about when to allocate effort (e.g., if extreme winter weather conditions are predicted) and when to consider alternative methods (e.g., if capture of ad M is an objective).     

Use of Bait to Increase Archery Deer Harvest in an Urban–Suburban Landscape

Abstract: Hunting is the primary tool for managing white-tailed deer (Odocoileus virginianus) populations. Effectiveness of hunting in suburban areas may be reduced due to limited hunter access to small properties, firearms-discharge laws, and public safety concerns. In Connecticut, USA, hunting over bait on private land was recently legalized to increase harvest opportunities. Our objective was to assess bow-hunter willingness to use bait and effects of bait type, hunter disturbance, time spent hunting, and property size on deer-harvest potential in a suburban landscape. We mailed a prebaiting survey in February 2002 and a postbaiting survey in February 2004 to the same group of hunters. Hunters using bait were more successful and harvested more deer than hunters using no bait. Hunters using bait on small properties observed similar numbers of deer within shooting range as hunters using bait on larger properties. Hunters using bait met their venison needs, whereas hunters using no bait did not meet their needs. Resource managers should implement strategies that increase hunter success when developing urban deer-management programs for communities.     

Site Occupancy Dynamics of Northern Spotted Owls in the Eastern Cascades,Washington, USA, 1990–2003

Abstract: Northern spotted owls (Strix occidentalis caurina) have received intense research and management interest since their listing as a threatened species by the United States Fish and Wildlife Service in 1990. Several spotted owl (Strix occidentalis) response variables have been examined in various investigations, but recent advances in statistical modeling permit evaluations of temporal and spatial variability in site occupancy, local-extinction, and colonization probabilities while incorporating imperfect detection probabilities. Following recent work by other researchers on site occupancy dynamics of spotted owls in Oregon, USA, we evaluated temporal variability of detection, occupancy, local-extinction, and colonization probabilities for spotted owls, as well as potential influences of barred owl (Strix varia) presence on these parameters. We used spotted owl survey data collected from 1990 to 2003 on a study area in the eastern Cascades Mountains, Washington, USA, to compare competing occupancy models from Program PRESENCE using Akaike's Information Criterion. Detection probabilities for individual spotted owls ranged from 0.54 to 0.80 if barred owls were not detected during the survey season and from 0.19 to 0.71 if barred owls were detected during the survey season. Pair detection probabilities ranged from 0.27 to 0.67 if barred owls were not detected during an individual survey and from 0.09 to 0.36 if barred owls were detected during an individual survey. During the study, site occupancy probabilities for spotted owl pairs declined by approximately 50%. For all spotted owls, both singles and pairs, site occupancy probabilities declined moderately during the study. Barred owl presence was negatively associated with spotted owl detection probabilities, and it had a positive association with local-extinction probabilities for all spotted owls, both singles and pairs. Given that our study area has supported higher densities of barred owls for longer periods than other study areas, our results may provide insight into how barred owls have influenced spotted owl site occupancy dynamics in adjacent British Columbia, Canada, or will influence spotted owl site occupancy dynamics in Oregon and California, USA, in the future.     

Non-Nervous Conduction in Invertebrates and Embryos

Propagated electrical events in epithelial tissues have beenrecorded from a number of invertebrates and from vertebrateembryos. Those groups in which such events have been recordedare the Cnidaria, Ctenophora, Echinodermata, Urochordata, andAmphibia. In several cases these non-nervous action potentialsmediate escape or protective responses. In other cases theycause ciliary reversal or arrest of ciliary beat. Propagationappears to occur via low resistance intercellular pathways involvingdirect current flow. The ontogeny of such epithelial impulsesis described in an amphibian.     

Explaining the latitudinal gradient anomaly in ichneumonid species richness: evidence from butterflies

1. Despite the profusion of Lepidoptera and other potential hosts in the tropics, the Ichneumonidae are not more species-rich in the lowland tropics than in temperate communities. Alternate but partially complementary hypotheses emphasizing resource fragmentation, predation, or chemical defence have been proposed to explain this paradox.
2. Because different diversity gradients occur in the various subgroups of the Ichneumonidae, as well as among their hosts, general explanations are unlikely to account for this 'anomalous diversity.' Hypotheses of ecological causation are best tested at the taxonomic level where the pattern of interest applies.
3. Phylogenetic trends in the distribution, abundance, and palatability of butterflies (Papilionoidea), a group that increases dramatically in species richness towards the tropics, are presented as a case study for evaluating hypotheses of parasitoid species richness. Evidence is presented that supports the 'nasty host hypothesis' as an explanation for the lack of diversity of associated parasitoids.
4. An examination of hypotheses and the approaches used to test them suggests that the nasty-host hypothesis is best supported by the limited evidence available, while evidence in favour of other hypotheses is either lacking or ambiguous. In particular, use of the koinobiont/idiobiont dichotomy and parasitoid assemblage-size comparisons may result in contradictory conclusions.