Nest predation in Australian urban environments and the role of the pied currawong,Strepera graculina

Abstract An experiment, involving 2000 members of the public, determined the identity of nest predators in urban environments. Experimental nests of halved tennis balls covered with coconut fibre and wool were manufactured to resemble the nests of willie wagtails, Rhipidura leucophrys. The identity of predators was determined by analysis of imprints left in artificial eggs made of coloured modelling clay. Sixty-four per cent of nests were preyed upon, with most predation being the result of large birds. Direct observations of predation (n = 134) indicated that pied currawongs were the most common large bird, accounting for 52% of all predation. Predation incidence was higher in gardens with more trees and in which kookaburras, Dacelo novaeguineae, were fed frequently. Among nests placed in trees, nest predation was correlated with nest height. Eggs camouflaged by speckling experienced a similar incidence of predation to plain eggs. This study provides evidence to support the contention that pied currawongs are a major threat to the persistence of small birds in Australian urban environments.     

Lessons learned in developing community mental health care in Latin American and Caribbean countries

This paper summarizes the findings for the Latin American and Caribbeancountries of the WPA Task Force on Steps, Obstacles and Mistakes to Avoidin the Implementation of Community Mental Health Care. It presents an overviewof the provision of mental health services in the region; describes key experiencesin Argentina, Belize, Brazil, Chile, Cuba, Jamaica and Mexico; and discussesthe lessons learned in developing community mental health care.     

Historical and projected interactions between climate change and insect voltinism in a multivoltine species

Climate change can cause major changes to the dynamics of individual species and to those communities in which they interact. One effect of increasing temperatures is on insect voltinism, with the logical assumption that increases in surface temperatures would permit multivoltine species to increase the number of generations per year. Though insect development is primarily driven by temperature, most multivoltine insect species rely on photoperiodic cues, which do not change from year‐to‐year or in response to climate warming, to initiate diapause. Thus, the relationship between climate change and voltinism could be complex. We use a phenology model for grape berry moth, Paralobesia viteana (Clemens), which incorporates temperature‐dependent development and diapause termination, and photoperiod‐dependent diapause induction, to explore historical patterns in year‐to‐year voltinism fluctuations. We then extend this model to predict voltinism under varying scenarios of climate change to show the importance of both the quality and quantity of accumulated heat units. We also illustrate that increases in mean surface temperatures > 2 °C can have dramatic effects on insect voltinism by causing a shift in the ovipositional period that currently is subject to diapause‐inducing photoperiods.     

One hundred years of eruptions of house mice in Australia – a natural biological curio

The house mouse has adapted well to the cereal crops of south-eastern Australia where populations show aperiodic outbreaks over large areas. A 20-year population study has provided a wealth of information on breeding ecology, demographic changes, spatial behaviour and epidemiology. The breeding season can be as short as 4.5 months and as long as 10 months with litter size changing seasonally from high values in spring to low values in autumn. There are marked changes in litter size between years. Rates of increase of populations also vary between years. The rate of change of populations during the breeding season is independent of density effects, but if the population density is high at the commencement of breeding then the litter size is depressed throughout that breeding season. There are density-dependent effects on survival during the non-breeding season. Rates of increase of populations over spring and summer are highly correlated with accumulated rainfall from the previous winter–spring (April–October). Studies of helminths and viruses indicate that Australian mice carry only a subset of the helminths found in Europe. There have been no published studies on murine viruses in Europe. Perhaps a reduced diversity of diseases partially accounts for the ability of mice to increase rapidly to extreme population densities in cereal-growing areas of south-eastern Australia.  © 2005 CSIRO, Biological Journal of the Linnean Society , 2005, 84 , 617–627.     

An Integrated Vehicle-Mounted Telemetry System for VHF Telemetry Applications

Abstract: We designed and developed a vehicle-mounted very high frequency-based telemetry system that integrated an on-board antenna, receiver, electronic compass, Global Positioning System, computer, and Geographic Information System. The system allows users to accurately and quickly obtain fixes, estimate and confirm locations of radiomarked animals, and immediately record data into an electronic spreadsheet or database. The total cost of materials to build the system was $7,349 (United States currency). Mean error angle of 2.63 ± 12.1° (SD; range = −33.7–42.2°) and mean location error distance of 128 ± 91.3 m (SD; range = 0–408 m) suggested precision and accuracy of our system were comparable to other reported systems. Mean time to record 5 bearings/test transmitter was 6.28 ± 0.24 minutes (SE), which is the most efficient system reported to locate animals in the field. Vehicle-mounted telemetry systems like ours provide additional value to studies that involve tracking highly mobile species because investigators need not take bearings from established receiving stations and because investigators can immediately recognize bounced signals and take additional bearings and optimize accuracy of location estimates.     

Black Hunger: Soul Food and America

Black Hunger: Soul Food and America . Doris Witt. Minneapolis: University of Minnesota Press, 2004. 292 pp.     

Effects of growth under elevated UV-B on photosynthesis and isoprene emission in Quercus gambelii and Mucuna pruriens

Increasing surface levels of UV-B resulting from stratospheric ozone reduction directly affect tropospheric photochemistry. There may also be indirect tropospheric effects due to changes in emission of organic compounds from vegetation. We treated woody and herbaceous isoprene-emitting species in the field with supplemental UV-B simulating 30% ozone depletion. For Quercus gambelii, photosynthesis and isoprene emission were significantly greater in elevated UV-B treatments when expressed on a leaf area basis, but not on a leaf mass basis. Leaves of Mucuna pruriens, however, showed no significant differences in photosynthesis or isoprene emission between treatments, nor when exposed for 45 min to acute high levels of UV-B. Elevated UV-B during growth did not elicit significant isoprene emission from Acer platanoides, a non-emitting species. Other potential UV-B effects, such as changes in leaf area or species composition, which may influence regional isoprene emissions, should be examined.     

A High Arctic soil ecosystem resists long‐term environmental manipulations

We evaluated above‐ and belowground ecosystem changes in a 16 year, combined fertilization and warming experiment in a High Arctic tundra deciduous shrub heath (Alexandra Fiord, Ellesmere Island, NU, Canada). Soil emissions of the three key greenhouse gases (GHGs) (carbon dioxide, methane, and nitrous oxide) were measured in mid‐July 2009 using soil respiration chambers attached to a FTIR system. Soil chemical and biochemical properties including Q₁₀ values for CO₂, CH₄, and N₂O, Bacteria and Archaea assemblage composition, and the diversity and prevalence of key nitrogen cycling genes including bacterial amoA, crenarchaeal amoA, and nosZ were measured. Warming and fertilization caused strong increases in plant community cover and height but had limited effects on GHG fluxes and no substantial effect on soil chemistry or biochemistry. Similarly, there was a surprising lack of directional shifts in the soil microbial community as a whole or any change at all in microbial functional groups associated with CH₄ consumption or N₂O cycling in any treatment. Thus, it appears that while warming and increased nutrient availability have strongly affected the plant community over the last 16 years, the belowground ecosystem has not yet responded. This resistance of the soil ecosystem has resulted in limited changes in GHG fluxes in response to the experimental treatments.     

At what spatial scales does resource selection vary? A case study of koalas in a semi‐arid region

The conservation of any species requires understanding and predicting the distribution of its habitat and resource use, including the effects of scale‐dependent variation in habitat and resource quality. Consequently, testing for resource selection at the appropriate scales is critical. We investigated how the resource selection process varies across scales, using koalas in a semi‐arid landscape of eastern Australia as a case study. We asked: at what scales does tree selection by koalas vary across regions? We tested the importance of the variation of our ecological predictors at the following scales: (i) the site‐scale (a stand of trees representing an individual koala's perception of local habitat); (ii) the landscape‐scale (10 × 10 km area representing a space within which a population of koalas exists); and (iii) a combination of these scales. We used a mixed‐modelling approach to quantify variation in selection of individual trees by koalas among sites and landscapes within a 1600 km² study area. We found that tree species, and tree height, were the most important factors influencing tree selection, and that their effect did not vary across scales. In contrast, preferences for trees of different condition, which is the state of tree canopy health, did vary across landscapes, indicating spatial variation in the selection of trees with respect to tree condition at the landscape‐scale, but not at the site‐scale. We conclude that resource selection processes can depend on the quality of those resources at different scales and their heterogeneous nature across landscapes, highlighting the consequence of scale‐dependent ecological processes. Designing studies that capture the heterogeneity in habitat and resources used by species that have an extensive distribution is an important prerequisite for effective conservation planning and management.