729 research outputs found

    Seasonal feeding on bark by gorillas: an unexpected keystone food?

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    First paragraph: There are a number of reports in the literature of primates feeding on the bark of trees, but bark has only occasionally been considered as a major food to be studied in its own right (e.g., Waser, 1977; Beeson, 1987; Norris, 1988). All the great apes feed on bark at certain times, and clearly have preferences as to which species they choose (e.g., Schaller, 1963; Jones & Sabater Pi. 1971; Casimir, 1975: Nishida, 1976; Goodall, 1977; Rodman, 1977; Sabater Pi, 1977, 1979). Evidence has been presented that bark feeding by chimpanzees (Pan troglodytes) and orangutans (Pongo pygmaeus) is a seasonal phenomenon related to scarcity of preferred fruits (Nishida, 1976; Rodman, 1977), and similar conclusions have been drawn from studies of blue monkeys (Cercopithecus mitis) living near plantations of exotic pines (Beeson, 1987; Maganga & Wright, 1992). Bark feeding is also well known in other mammals where, again, it often occurs seasonally (e.g., elephants, Wing & Buss, 1970; grey squirrels, Kenward & Parish, 1986)

    Human activity was a major driver of the mid-Holocene vegetation change in southern Cumbria: Implications for the elm decline in the British Isles

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    This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.The dramatic decline in elm (Ulmus) across a large swathe of north-west Europe in the mid-Holocene has been ascribed to a number of possible factors, including climate change, human activity and/or pathogens. A major limitation for identifying the underlying cause(s) has been the limited number of high-resolution records with robust geochronological frameworks. Here, we report a multiproxy study of an upland (Blea Tarn) and lowland (Urswick Tarn) landscape in southern Cumbria (British Isles) to reconstruct vegetation change across the elm decline in an area with a rich and well-dated archaeological record to disentangle different possible controls. Here we find a two-stage decline in Ulmus taking place between 6350–6150 and 6050–5850 cal a BP, with the second phase coinciding with an intensification of human activity. The scale of the decline and associated human impact is more abrupt in the upland landscape. We consider it likely that a combination of human impact and disease drove the Ulmus decline within southern Cumbria.This work was funded by a studentship for MJG from the University of Exeter and Sir John Fisher Foundation. Additional funding for 14C dating was from the Cumberland and Westmorland Antiquarian and Archaeological Society (Clare Fell Bursary to MJG), and the Australian Research Council (FL100100195)

    The effects of stand characteristics on the understory vegetation in Quercus petraea and Q. cerris dominated forests

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    The shelterwood system used in Hungary has many effects on the composition and structure of the herb layer. The aim of our study was to identify the main variables that affect the occurence of herbs and seedlings in Turkey oak-sessile oak (Quercus cerris and Q. petraea) stands. The study was carried out in the Bükk mountains, Hungary. 122 sampling plots were established in 50-150 year old oak forests, where we studied the species composition and structure of the understorey and overstorey. The occurence of herbs was affected by canopy closure, the heterogenity and patchiness of the stand, the slope and the east-west component of the aspect. The composition of saplings was significantly explained by the ratio of the two major oak species in the stand and the proximity of the adult plants. An important result for forest management was that sessile oaks were able to regenerate almost only where they were dominant in the overstorey

    Chimpanzees Share Forbidden Fruit

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    The sharing of wild plant foods is infrequent in chimpanzees, but in chimpanzee communities that engage in hunting, meat is frequently used as a ‘social tool’ for nurturing alliances and social bonds. Here we report the only recorded example of regular sharing of plant foods by unrelated, non-provisioned wild chimpanzees, and the contexts in which these sharing behaviours occur. From direct observations, adult chimpanzees at Bossou (Republic of Guinea, West Africa) very rarely transferred wild plant foods. In contrast, they shared cultivated plant foods much more frequently (58 out of 59 food sharing events). Sharing primarily consists of adult males allowing reproductively cycling females to take food that they possess. We propose that hypotheses focussing on ‘food-for-sex and -grooming’ and ‘showing-off’ strategies plausibly account for observed sharing behaviours. A changing human-dominated landscape presents chimpanzees with fresh challenges, and our observations suggest that crop-raiding provides adult male chimpanzees at Bossou with highly desirable food commodities that may be traded for other currencies

    Sex differences in the movement patterns of free-ranging chimpanzees (Pan troglodytes schweinfurthii): foraging and border checking

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    Most social primates live in cohesive groups, so travel paths inevitably reflect compromise: decision processes of individuals are obscured. The fission-fusion social organisation of the chimpanzee, however, allows an individual’s movements to be investigated independently. We followed 15 chimpanzees (8 male and 7 female) through the relatively flat forest of Budongo, Uganda, plotting the path of each individual over periods of 1-3 days. Chimpanzee movement was parsed into phases ending with halts of more than 20 minutes, during which individuals fed, rested or engaged in social activities. Males, lactating or pregnant females, and sexually receptive females all travelled similar average distances between halts, at similar speeds, and along similarly direct beeline paths. Compared to lactating or pregnant females, males did travel for a significantly longer time each day and halted more often, but the most striking sex differences appeared in the organisation of movement phases into a day’s path. After a halt, males tended to continue in the same direction as before. Lactating or pregnant females showed no such strategy and often retraced the preceding phase, returning to previously visited food patches. We suggest that female chimpanzee movements approximate an optimal solution to feeding requirements, whereas the paths of males allow integration of foraging with territorial defence. The ‘continually moving forwards’ strategy of males enables them to monitor their territory boundaries – border checking – whilst foraging, generally avoiding the explicit boundary patrols observed at other chimpanzee study sites

    Archival data on wild food plants used in Poland in 1948

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    <p>Abstract</p> <p>Background</p> <p>In 1948, Professor Józef Gajek initiated a detailed census of the wild edible plants used in Poland. The questionnaires were collected by correspondents of the Polish Folklore Society in 95 localities throughout Poland. A major part of these archival materials, including a substantial collection of herbarium specimens, had not undergone thorough analysis prior to this study, which presents a quantitative analysis of this archival set of data.</p> <p>Methods</p> <p>Herbarium specimens were identified and a database was created.</p> <p>Results</p> <p>Ninety-eight taxa identified to genus or species level, including 71 botanical species, identified using herbarium specimens, were found. On average only 11 edible plant species per locality were listed, the longest list included 39 species. No correlation between latitude and the number of edible species was found, whereas there was small but significant correlation with the longitude. Fruits were the most frequently collected part of plants. Most plants were primarily collected by women and children. Children both helped parents to collect wild fruits and also ate many species raw, which were not consumed by adults, but had often been eaten in the past. Eighteen of the taxa had not been reported in a recent comprehensive review of edible plants of Poland. <it>Stratiotes aloides</it>, used as a famine vegetable in the Łódź region, has never been reported as edible in any ethnobotanical literature.</p> <p>Conclusion</p> <p>The results undermine the conclusions of a recent comprehensive review of edible plants of Poland, which stated that many more wild edible plants have been collected in the Carpathians than in lowland Poland. However such results were shown to be caused by the substantially larger number of ethnographic studies undertaken in the Carpathians. In fact, large numbers of edible plant species were collected in the mid-20<sup>th </sup>century in a few regions, particularly along the eastern border, in the Carpathians and in communities originating from the expanded Soviet Union, which had been resettled to the north-west of Poland in 1945.</p

    Catastrophic Decline of World's Largest Primate: 80% Loss of Grauer's Gorilla (Gorilla beringei graueri) Population Justifies Critically Endangered Status

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    Grauer's gorilla (Gorilla beringei graueri), the World's largest primate, is confined to eastern Democratic Republic of Congo (DRC) and is threatened by civil war and insecurity. During the war, armed groups in mining camps relied on hunting bushmeat, including gorillas. Insecurity and the presence of several militia groups across Grauer's gorilla's range made it very difficult to assess their population size. Here we use a novel method that enables rigorous assessment of local community and ranger-collected data on gorilla occupancy to evaluate the impacts of civil war on Grauer's gorilla, which prior to the war was estimated to number 16,900 individuals. We show that gorilla numbers in their stronghold of Kahuzi- Biega National Park have declined by 87%. Encounter rate data of gorilla nests at 10 sites across its range indicate declines of 82-100% at six of these sites. Spatial occupancy analysis identifies three key areas as the most critical sites for the remaining populations of this ape and that the range of this taxon is around 19,700 km2. We estimate that only 3,800 Grauer's gorillas remain in the wild, a 77% decline in one generation, justifying its elevation to Critically Endangered status on the IUCN Red List of Threatened Species

    Challenges for automatically extracting molecular interactions from full-text articles

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    <p>Abstract</p> <p>Background</p> <p>The increasing availability of full-text biomedical articles will allow more biomedical knowledge to be extracted automatically with greater reliability. However, most Information Retrieval (IR) and Extraction (IE) tools currently process only abstracts. The lack of corpora has limited the development of tools that are capable of exploiting the knowledge in full-text articles. As a result, there has been little investigation into the advantages of full-text document structure, and the challenges developers will face in processing full-text articles.</p> <p>Results</p> <p>We manually annotated passages from full-text articles that describe interactions summarised in a Molecular Interaction Map (MIM). Our corpus tracks the process of identifying facts to form the MIM summaries and captures any factual dependencies that must be resolved to extract the fact completely. For example, a fact in the results section may require a synonym defined in the introduction. The passages are also annotated with negated and coreference expressions that must be resolved.</p> <p>We describe the guidelines for identifying relevant passages and possible dependencies. The corpus includes 2162 sentences from 78 full-text articles. Our corpus analysis demonstrates the necessity of full-text processing; identifies the article sections where interactions are most commonly stated; and quantifies the proportion of interaction statements requiring coherent dependencies. Further, it allows us to report on the relative importance of identifying synonyms and resolving negated expressions. We also experiment with an oracle sentence retrieval system using the corpus as a gold-standard evaluation set.</p> <p>Conclusion</p> <p>We introduce the MIM corpus, a unique resource that maps interaction facts in a MIM to annotated passages within full-text articles. It is an invaluable case study providing guidance to developers of biomedical IR and IE systems, and can be used as a gold-standard evaluation set for full-text IR tasks.</p

    Effect of Resting Patterns of Tamarins (Saguinus fuscicollis and Saguinus mystax) on the Spatial Distribution of Seeds and Seedling Recruitment

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    The spatial distributions of dispersed seeds have important evolutionary consequences for plants. Repeated defecations in sites frequently used by seed dispersers can result in high seed concentrations. We observed the resting behavior of a mixed-species group of tamarins in Peru and recorded the occurrence of seed dispersal (over 8 mo) and seed fate (over 11–22 mo) to determine whether the location and use of resting sites influenced the spatial distribution of dispersed seeds and seedlings. The tamarins rested mostly on trees (Saguinus fuscicollis: 60.6%, S. mystax: 89.2%) and dead trunks (S. fuscicollis: 24.4%) and used 61% of their resting sites repeatedly. During both the dry and wet seasons, tamarins dispersed significantly more seeds within resting areas (0.00662 and 0.00424 seeds/m2, respectively) than outside them (0.00141 and 0.00181 seeds/m2). Seed survival and seedling recruitment did not differ significantly between resting and other areas, resulting in a higher seedling concentration around the resting sites. Seed density did not increase with the duration or the frequency of use of the resting sites but did increase when we pooled the seasonal resting sites together in 50 m × 50 m quadrats, ultimately causing a clumped distribution of dispersed seeds. The use of resting sites in secondary forest, particularly during the dry season, allows the creation of seedling recruitment centers for species coming from the primary forest. Our findings show that tamarin resting behavior affects the spatial distribution of dispersed seeds and seedlings, and their resting sites play an important role in plant diversity maintenance and facilitate forest regeneration in degraded areas
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