Central place foraging in wheatears (Oenanthe oenanthe L.): foraging itineraries when feeding nestlings

Summary Parent wheatears (Oenanthe oenanthe L.), foraging to meet their own needs and to provide food for a central place (CP, i.e. the nest), have to make decisions with respect to the configuration of foraging itineraries during round trips in the territory and to the directionality of their movements. These problems were studied in two pairs breeding in an agricultural area in central Swecen. All birds started a round trip by hunting from perches close to the CP and then moving to perches progressively further away in a roughly straight line until the first prey item was loaded. Loaded prey were either delivered singly (single prey loading: SPL) or with other prey (multiple prey loading: MPL). When the bird decided to return with several items to the CP, it abruptly changed the direction of its movements by making a left, right or backward turn and started to visit perches progressively nearer the CP, again following a roughly straight line. The decision to return continue loading was affected by the size of the prey as shown by the fact that prey carried singly was significantly larger than the first item in an MPL for all individuals. The distance to the CP also seemed to affect this decision as prey provisioned singly on average were collected significantly closer to the nest than the first item in an MPL by one pair. Both the size of prey loaded singly and load size of MPL increased with distance from the CP in one pair. The concentrated use of the territory in the other pair made any effect of distance difficult to detect. Great flexibility in foraging decisions was observed in cases when an individual, because of the size of the last prey captured, altered its decision to deliver an MPL and transported an SPL to the nest instead. On the basis of these results we propose a set of rules followed by predators such as wheatears when making decisions about delivering prey to a CP (Fig. 4).     

Benthic bioluminescence in the bathyal North East Atlantic: luminescent responses of <Emphasis Type="Italic">Vargula norvegica</Emphasis> (Ostracoda: Myodocopida) to predation by the deep-water eel (<Emphasis Type="Italic">Synaphobranchus kaupii</Emphasis>)

Using two autonomous lander systems, one equipped with a high sensitivity intensified silicon intensifier target (ISIT) video camera and a second with a 4.1-megapixel digital stills camera, observations were made of bioluminescent emissions and fauna attracted to artificial food falls at ca. 1,000 m depth in the carbonate mound provinces of the Porcupine Seabight and Rockall Bank, North East Atlantic. On the Galway coral mound (Belgica Mound Province), seven bioluminescent events per hour were observed, whereas on an area of sediment at the base of the Kiel Mount on the Rockall Bank 133 events per hour were observed. This increase in bioluminescent activity was associated with the presence of the deep water eels Synaphobranchus kaupii, and the ostracods, Vargula norvegica. Captured ostracods luminesced readily in response to mechanical stimulation and were also observed emitting a luminous secretion. We hypothesise that V. norvegica, attracted to bait, luminesce as a defence response against the predatory activity of S. kaupii that compete for bait but also feed on the ostracods. Benthic bioluminescence in the carbonate mound provinces was not directly linked to the presence of corals.     

Effect of phosphate on heterogeneous Fenton oxidation of catechol by nano-Fe3O4: Inhibitor or stabilizer?

The effect of phosphate on adsorption and oxidation of catechol, 1,2-dihydroxybenzene, in a heterogeneous Fenton system was investigated. In situ attenuated total reflectance infrared spectroscopy (ATR-FTIR) was used to monitor the surface speciation at the nano-Fe₃O₄ catalyst surface. The presence of phosphate decreased the removal rate of catechol and the abatement of dissolved organic compounds, as well as the decomposition of H₂O₂. This effect of phosphate was mainly due to its strong reaction with surface sites on the iron oxide catalyst. At neutral and acid pH, phosphate could displace the adsorbed catechol from the surface of catalyst and also could compete for surface sites with H₂O₂. In situ IR spectra indicated the formation of iron phosphate precipitation at the catalyst surface. The iron phosphate surface species may affect the amount of iron atoms taking part in the catalytic decomposition of H₂O₂ and formation of hydroxyl radicals, and inhibit the catalytic ability of Fe₃O₄ catalyst. Therefore, phosphate ions worked as stabilizer and inhibitor in a heterogeneous Fenton reaction at the same time, in effect leading to an increase in oxidation efficiency in this study. However, before use of phosphate as pH buffer or H₂O₂ stabilizer in a heterogeneous Fenton system, the possible inhibitory effect of phosphate on the actual removal of organic pollutants should be fully considered.     

Agency–Community Partnership in Landcare: Lessons for State-Sponsored Citizen Resource Management

/ With over 2500 Australian Landcare groups, 65,000 volunteer members, and considerable evidence of program impact, Landcare is an important example of state-sponsored rural development in a developed nation. The agency-community partnership is a fundamental element of Landcare and getting the partnership right is vital to long-term program success. After reviewing the emergence of Landcare in the state of Victoria, the author reports research from a 1995 survey of Victorian Landcare groups. Survey information highlighted the extent of agency-group contact, the important roles agency staff played in many Landcare groups, and the positive impact of agency contact and government funding upon group activity. Large majorities of groups reported they were satisfied with their relationship with agency staff. However, a majority of groups reported money or materials provided to manage land and water degradation was inadequate. Recently proposed changes to the Landcare program will provide government funding of work on private property and may address this concern. A majority of groups also reported support for leadership and management training was inadequate and respondents emphasized the need to revise program guidelines that limit funding for group coordinators. This information highlighted the importance of articulating a practical model of community participation in Australia and adopting a systematic approach to providing agency support for Landcare groups. Reflecting upon the Landcare experience, the author suggests some of the key elements of a practical model of state-sponsored citizen resource management contributing to rural development.KEY WORDS: Landcare; Australia; Community participation; Rural development; Citizen resource management; Sustainable agriculture     

Relationship of Indoor N02 Concentrations to Use of Unvented Gas Appliances

In preparation for a prospective study of the relationship of residential nitrogen dioxide exposure and respiratory infections in infants, we conducted a pilot study to assess NO₂ concentrations in a sample of homes in Albuquerque, New Mexico. The methods used to characterize concentrations are described. Three locations in 144 homes were monitored with passive diffusion samplers for two two-week cycles during November and December 1984. Two-week average NO₂ concentrations in the activity room ranged from 2.0 to 168.7 ppb. NO₂ concentrations in the activity room and the infant’s bedroom were fivefold higher in homes with gas stoves than in homes with electric stoves. Sixty-four percent of homes with gas stoves had activity room concentrations that exceeded the highest outdoor concentration. Multiple regression models Indicated that the outdoor concentration, use of a gas stove, particularly one with pilot lights, presence of a gas dryer in the living area, and use of a floor or wall furnace contributed to NO₂ concentrations. Use of a toaster or microwave oven in a house with a gas stove reduced NO₂ concentrations. The results of this study demonstrate a broad range of NO₂ concentrations in Albuquerque. We conclude with suggestions for an exposure assessment strategy that would be valid and feasible in the context of a large epidemiologic study of the health effects of NO₂.     

Vehicles driven by teenagers in their first year of licensure

OBJECTIVE: to determine access to vehicles, vehicle ownership and its correlates, and types of vehicles driven by teenagers during their first year of licensure. METHODS: About 3,500 Connecticut teenagers and their parents recruited at DMV offices participated in a study aimed at persuading parents to impose and maintain driving restrictions on their sons and daughters. Telephone interviews with teens and parents, which included questions on vehicles driven, were conducted upon licensure and at intervals throughout the year. RESULTS: The majority of both male and female teens owned vehicles immediately upon licensure. Family income and number of vehicles in the family were associated with early ownership. A year later 74% owned vehicles. Small cars, which provide inferior crash protection, were the most popular vehicle; the percent driving small cars increased from 36% to 42% over the year. About 25% were driving SUVs, pickups, or sports cars, which may increase crash risk for young beginners. One year after licensure, only 35% of teens were driving midsize or large passenger cars, the types of vehicles recommended for them, and about one-third of these vehicles were 10 or more years old. Owners were more likely than non-owners to drive older and smaller vehicles, to drive more miles, do more risky driving, and to have more traffic violations and crashes. DISCUSSION: Many teenagers in Connecticut were driving vehicles that rank low in crash protection or may increase crash risk. Attention to the young driver problem has been focused primarily on managing driving risks through graduated licensing systems. More attention needs to be given to the vehicles teens drive, and how decisions about vehicle type and ownership are made. Parents exert control over what vehicles their sons and daughters drive, and may benefit from information on how to make choices that better balance cost, safety, and other factors that go into these decisions.     

Mineralisation of 2,6-dichlorobenzamide (BAM) in dichlobenil-exposed soils and isolation of a BAM-mineralising Aminobacter sp

Mineralisation of the groundwater contaminant 2,6-dichlorobenzamide (BAM), a metabolite from the herbicide 2,6-dichlorobenzonitrile (dichlobenil), was studied in soil samples obtained from 39 locations previously exposed to dichlobenil. Rapid BAM mineralisation was detected in samples from six locations with 5.2-64.6% of the added BAM mineralised within 48-50 days. From one location rapid BAM mineralisation was observed in soil samples down to a depth of 2 m below the surface. One location with fast BAM mineralisation showed significant dichlobenil degradation activity with 25.5% of the added dichlobenil being mineralised within 50 days. By inoculating soil showing the fastest mineralisation of BAM into a mineral medium with BAM as the only carbon and nitrogen source an enrichment culture was established. Community analysis based on extracted DNA revealed a change of the bacterial community but without any clear indication of key members within the BAM-mineralising culture. Parallel cultivation resulted for the first time in the isolation of a BAM-mineralising bacterium, identified as an Aminobacter sp.     

Prediction of mono- and polycyclic aromatic hydrocarbon degradation in spiked soils using cyclodextrin extraction

In this study, an aqueous-based hydroxypropyl-beta-cyclodextrin (HPCD) extraction technique was assessed for its capacity to determine the microbially degradable fraction of mono- and polycyclic aromatic hydrocarbons in four dissimilar soils. A linear relationship (slope=0.90; R2=0.89), approaching 1:1 between predicted and observed phenanthrene mineralization, was demonstrated for the cyclodextrin extraction; however, the water only extraction underestimated the microbially available fraction by a factor of three (slope=3.35; R2=0.64). With respect to determining the mineralizable fraction of p-cresol in soils, the cyclodextrin extraction (slope=0.94; R2=0.84) was more appropriate than the water extraction (slope=1.50; R2=0.36). Collectively, these results suggested that the cyclodextrin extraction technique was suitable for the prediction of the mineralizable fraction of representative PAHs and phenols present in dissimilar soils following increasing soil-contaminant contact times. The assessment of the microbial availability of contaminants in soils is important for a more representative evaluation of soil contamination.     

Impact of Urban Sprawl on Water Quality in Eastern Massachusetts,USA

A study of water quality, land use, and population variations over the past three decades was conducted in eastern Massachusetts to examine the impact of urban sprawl on water quality using geographic information system and statistical analyses. Since 1970, eastern Massachusetts has experienced pronounced urban sprawl, which has a substantial impact on water quality. High spatial correlations are found between water quality indicators (especially specific conductance, dissolved ions, including Ca, Mg, Na, and Cl, and dissolved solid) and urban sprawl indicators. Urbanized watersheds with high population density, high percentage of developed land use, and low per capita developed land use tended to have high concentrations of water pollutants. The impact of urban sprawl also shows clear spatial difference between suburban areas and central cities: The central cities experienced lower increases over time in specific conductance concentration, compared to suburban and rural areas. The impact of urban sprawl on water quality is attributed to the combined effects of population and land-use change. Per capita developed land use is a very important indicator for studying the impact of urban sprawl and improving land use and watershed management, because inclusion of this indicator can better explain the temporal and spatial variations of more water quality parameters than using individual land use or/and population density.