Carbofuran residues in organic soils in Southwestern Ontario, 1977

Organic soils from 22 farms with a history of carbofuran use for soil insect control were sampled in November, 1977. Analysis for carbofuran was by electron capture gas chromatography of the heptaflurobutyric derivative. Nineteen of the 22 soils contained detectable (sensitivity 0.02 ppm) carbofuran residues. However only 8 of the soils contained greater than 0.5 ppm total carbofuran. The highest total carbofuran residue was 1.5 ppm, of which 0.31 ppm was 3-ketocarbofuran. In other soil samples 3-ketocarbofuran comprised 7-50% of the total carbofuran residue. No 3-hydroxycarbofuran was detected. The order of persistence of granular application of 3 insecticides as seed-furrow treatments was ethion greater than fonofos greater than carbofuran.     

Dynamics in the global protected-area estate since 2004

Nations of the world have committed to a number of goals and targets to address global environmental challenges. Protected areas have for centuries been a key strategy in conservation and play a major role in addressing current challenges. The most important tool used to track progress on protected-area commitments is the World Database on Protected Areas (WDPA). Periodic assessments of the world's protected-area estate show steady growth over the last 2 decades. However, the current method, which uses the latest version of the WDPA, does not show the true dynamic nature of protected areas over time and does not provide information on sites removed from the WDPA. In reality, this method can only show growth or remain stable. We used GIS tools in an approach to assess protected-area change over time based on 12 temporally distinct versions of the WDPA that quantify area added and removed from the WDPA annually from 2004 to 2016. Both the narrative of continual growth of protected area and the counter-narrative of protected area removal were overly simplistic. The former because growth was almost entirely in the marine realm and the latter because some areas removed were reprotected in later years. On average 2.5 million km² was added to the WDPA annually and 1.1 million km² was removed. Reasons for the inclusion and removal of protected areas in the WDPA database were in part due to data-quality issues but also to on-the-ground changes. To meet the 17% protected-area component of Aichi Biodiversity Target 11 by 2020, which stood at 14.7% in 2016, either the rate of protected-area removal must decrease or the rate of protected-area designation and addition to the WDPA must increase.     

High serum S-equol content in red clover fed ewes: the classical endocrine disruptor is a single enantiomer

An expedient high performance liquid chromatography (HPLC) method was developed for the quantitative analysis of environmental estrogenic isoflavonoids, particularly (S)-equol, in red clover fed ewes. We report here the phytoestrogen analysis of red clover silage and the serum of ewes fed with this feed. Ewes received daily 10.5 g of formononetin on average from red clover silage. In the serum samples a major part of formononetin had been metabolised to equol (average 7.7 μg ml⁻¹). According to chiral HPLC analysis, the equol present in the serum of ewes was solely of the (S)-form. We also demonstrate the presence of the metabolite O-demethylangolensin (O-DMA) in ovine serum.     

Widespread occurrence of extensive epimural rod bacteria in the hindguts of marine Thalassinidae and Brachyura (Crustacea: Decapoda)

Direct observation by scanning electron microscopy indicates that the presence of bacteria (epimural and unattached) in the hindguts of Crustacea is widespread, occurring across taxa (two infraorders, i.e., Brachyura and Thalassinidae, nine genera, 16 species), feeding types (detritivores, scavengers and carnivores), habitats (mangroves, saltmarshes, sand/mudflats) and continents (North America, South Africa, Australia). Crustacean hindguts clearly represent suitable environments for colonization by micro-organisms, despite the lack of specialized structures or modifications of the gut to facilitate this. Mats of closely-packed epimural rods and scattered epimural rods were the most common types of bacteria observed in the guts of the Crustacea examined, although unattached rods and scattered epimural cocci occurred in some species. There were, however, taxon-dependent differences in colonization characteristics of hindgut bacteria, possibly related to differences in gut lining. Abundance of hindgut microflora was unrelated to the host's taxon, habitat or geographical locality, but appeared to be affected by the feeding habits of the animal. Mats of epimural rods were associated exclusively with detritivores, while cocci were only observed in the hindguts of scavengers and carnivores. Moreover, extensive colonization by epimural rod bacteria (covering >50% of the hindgut lining) was observed in detritivores only, while carnivores harboured few or no rod bacteria. The detritivore hindgut appears to provide a better environment for microbial habitation than does that of carnivorous crustaceans. In all cases the rod bacteria were monocultures of morphologically identical bacteria and were remarkably similar among crustacean species. The potential significance of prolific microbial colonization in the hindguts of crustaceans deserves consideration.Communicated by O. Kinne, Oldendorf/Luhe     

Between-group contest competition for food in a highly folivorous population of black and white colobus monkeys (Colobus guereza)

In theory, between-group contest (BGC) competition for food can greatly influence female social relationships and reproductive success in primates, but few studies have investigated whether such effects occur and, if so, under what ecological conditions. There is evidence that adult male black and white colobus monkeys (Colobus guereza, “guerezas”) defend the food their mates need against other groups, suggesting that BGC competition is important in this species. Using data on feeding, ranging, vegetation patterns, and intergroup encounters between six neighboring guereza groups, I provide evidence that the highly folivorous guerezas at Kanyawara, Kibale National Park, Uganda, engaged in BGC competition over unevenly dispersed, relatively high-quality feeding areas or “core areas”. Intergroup aggression was common, and groups’ home ranges overlapped. Groups were more likely to initiate high-level aggression if they encountered another group within or near their core area, and groups that initiated and won encounters often fed in the same areas in which losing groups had fed. Guerezas fed selectively on species with contagious (clumped) distributions and concentrated their feeding efforts in areas of the forest that contained the most food (core areas). Groups could be ranked in a linear dominance hierarchy, and group rank number was inversely related to the quantity and quality of food in groups’ core areas. This study not only provides good evidence that BGC competition occurs in primates but it also reinforces the idea that folivore food resources may be worth defending.     

Recent Invasions of the Gulf of Maine: Three Contrasting Ecological Histories

Introduced species are common members of estuarine communities where their role as competitors and predators is of concern, This paper examines the invasion of Gulf of Maine benthic habitats by the ecologically similar alien invertebrates Styela clava, Botrylloides diegensis , and Membranipora membranacea .
Styela clava increased slowly in abundance at study sites in Beverly, Massachusetts and Portsmouth, New Hampshire. We found no evidence of competitive dominance by S. clava , even though it is the competitive dominant in similar habitats elsewhere. Botrylloides diegensis rapidly became a dominant species after its arrival in the Great Bay Estuary, but this dominance was short-lived. B. diegensis persists in the estuary as an early colonist of primary space and as an epibiont on secondary substrates in established communities. Membranipora membranacea became the dominant epiphyte on laminarian kelps within two years. Although M. membranacea overgrew the native epiphytes Obelia geniculata and Electra pilosa in the overwhelming majority of encounters these native species are more common on other algal hosts. Therefore, competitive dominance is not likely a factor in the successful invasion of the Gulf of Maine by M. membranacea .
These species provide evidence for opposing views of the role of competition in mediating community invasion. We show that ecological similarity among species is not an accurate criterion to predict either the mechanism of invasion or the means of persistence. In addition, these data indicate that biological invasions must be examined on broad spatial and temporal scales; short-term or narrowly focused studies can lead to incorrect conclusions.     

Choosing rewarding flowers; perceptual limitations and innate preferences influence decision making in bumblebees and honeybees

Flowers exhibit great intra-specific variation in the rewards they offer. At any one time, a significant proportion of flowers often contain little or no reward. Hence, foraging profitably for floral rewards is problematic and any ability to discriminate between flowers and avoid those that are less rewarding will confer great advantages. In this study, we examine discrimination by foraging bees among flowers of nasturtium, Tropaeolum majus. Bee visitors included carpenter bees, Xylocopa violacea, which were primary nectar robbers; honeybees, Apis mellifera, which either acted as secondary nectar robbers or gathered pollen legitimately and bumblebees, Bombus hortorum, which were the only bees able to gather nectar legitimately. Many flowers were damaged by phytophagous insects. Nectar volume was markedly lower in flowers with damaged petals (which were also likely to be older) and in flowers that had nectar-robbing holes. We test whether bees exhibit selectivity with regards to the individual flowers, which they approach and enter, and whether this selectivity enhances foraging efficiency. The flowers approached (within 2 cm) by A. mellifera and B. hortorum were non-random when compared to the floral population; both species selectively approached un-blemished flowers. They both approached more yellow flowers than would be expected by chance, presumably a reflection of innate colour preferences, for nectar standing crop did not vary according to flower colour. Bees were also more likely to accept (land on) un-blemished flowers. A. mellifera gathering nectar exhibited selectivity with regards to the presence of robbing holes, being more likely to land on robbed flowers (they are not able to feed on un-robbed flowers). That they frequently approached un-robbed flowers suggests that they are not able to detect robbing holes at long-range, so that foraging efficiency may be limited by visual acuity. Nevertheless, by using a combination of long-range and short-range selectivity, nectar-gathering A. mellifera and B. hortorum greatly increased the average reward from the flowers on which they landed (by 68% and 48%, respectively) compared to the average standing crop in the flower population. Overall, our results demonstrate that bees use obvious floral cues (colour and petal blemishes) at long-range, but can switch to using more subtle cues (robbing holes) at close range. They also make many mistakes and some cues used do not correlate with floral rewards.     

Functional responses of copepod nauplii using a high efficiency gut fluorescence technique

To investigate copepod nauplii ingestion rates on phytoplankton, we have adapted the traditional gut fluorescence technique as it can be used with lower gut pigment concentrations. With the improved technique, laboratory experiments were performed to estimate functional responses for nauplii of Calanus helgolandicus and Centropages typicus. Nauplii were raised from eggs to copepodites and the experiments were performed with stages NIV-NV. Gut evacuation rates and ingestion rates were measured on Isochrysis galbana at different concentrations. Specific ingestion rates ranged between 0.038–0.244 μg C μg⁻¹ nauplii C d⁻¹ for C. typicus and 0.041–1.412 μg C μg⁻¹ nauplii C d⁻¹ for C. helgolandicus. Both species showed a type III functional response, reaching a saturation concentration at around 600 μgC l⁻¹ for C. typicus and 800 μgC l⁻¹ for C. helgolandicus. An erratum to this article can be found at     

Effects of fenoxycarb exposure on complete larval development of the xanthid crab,Rhithropanopeus harrisii

Pest control agents, such as juvenile hormone analogues (JHA), have been developed to limit effects on non-target organisms that co-inhabit insect pest habitats. Rhithropanopeus harrisii, an estuarine xanthid crab, was used to observe the impacts of the JHA, fenoxycarb, on the pattern of complete larval development as well as survival of larvae and successful metamorphosis to first crab stage. Significant mortality occurred in the first of four zoeal stages (after 2-3 days of exposure) at the highest treatment of 240 microg fenoxycarb/l and in megalopae exposed to 48 microg fenoxycarb/l. The time required to metamorphose to the first crab stage was significantly increased for megalopae in all treatments 48 microg/l. This delay in development was sufficient to significantly prolong the entire developmental period from zoea to crabs. Unexposed larvae developed to crabs in an average of 16 days; larvae exposed to >/=48 microg/l required 19-20 days. Reduced survival and extended duration of developing larval stages in the life history of a benthic invertebrate may alter the population dynamics of these organisms in the estuary.