7 research outputs found

    Temporal variation in black-caiman-nest predation in varzea of central Brazilian amazonia

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    On the Amazon floodplain, the main predators of black caiman (Melanosuchus niger) eggs are jaguars (Panthera onca), tegu lizards (Tupinambis teguixim), capuchin monkeys (Sapajus macrocephalus) and humans (Homo sapiens). In this study, we investigated the relationship between predator attacks on nests and incubation period, and evaluated the influence of initial predation on subsequent predation in the Mamirauá Sustainable Development Reserve. We also evaluated the influence of presence of females near the nests and manipulation of nests on the occurrence of attacks. We compared results from data obtained with camera traps and vestiges left by predators on estimates of rates of predation by different predators. Egg predation was recorded in 32% of the 658 black caiman nests monitored during two years. Our results suggest that the probability of predation on black caiman eggs is relatively constant throughout the incubation period and that predation on eggs was lower when adults, presumably females, were present. Careful opening of nests and handling of eggs did not increase the number of attacks on black caiman nests. Nest opening by a predator appeared to increase the chances of a subsequent attack because most of the attacks on nests occurred soon after a predator first opened the nest. However, attacks by another species of predator do not appear to be necessary to initiate attacks by any other species of predator. Results based on camera traps and vestiges differed, but use of vestiges was adequate for identifying the principal predators on eggs in black caiman nests and, in many circumstances, the vestiges may be better for estimating predation by humans. In this study, opening nests and handling eggs did not increase the number of attacks on black caiman nests. © 2017 Torralvo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

    Taxonomy, phylogeny and identification of Botryosphaeriaceae associated with pome and stone fruit trees in South Africa and other regions of the world

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    Species of Botryosphaeria are well-recognized pathogens of pome and stone fruit trees. The taxonomy of these fungi, however, has been confused in the past. Recent taxonomic changes to the Botryosphaeriaceae further influence the literature pertaining to these fungi. This study reviews the taxonomic status of Botryosphaeriaceae associated with fruit tree diseases, identifies them in South Africa and elsewhere, and develops a reliable identification technique for them. Comparisons were made using DNA sequence data from the nuclear ITS rRNA operon and anamorph morphology. These analyses distinguished six clades amongst isolates associated with fruit tree diseases, corresponding to Neofusicoccum ribis (= B. ribis), N. parvum (= B. parva), N. australe (= B. australis), B. dothidea, Diplodia mutila (= B. stevensii) and ¿Botryosphaeria¿ obtusa (the genus Botryosphaeria is no longer available for the fungus known as B. obtusa, but a new name has not been proposed yet). Isolates from fruit trees in South Africa were grouped in the N. australe and ¿Botryosphaeria¿ obtusa clades. This is the first report of N. australe from fruit trees. PCR-RFLP analysis using the restriction endonucleases CfoI and HaeIII distinguished the major clades. However, two groups of closely related species, N. ribis and N. parvum, and N. australe and N. luteum (= B. lutea), had identical RFLP profiles. Using RFLP, it was shown that ¿Botryosphaeria¿ obtusa is the dominant species on fruit trees in the Western Cape Province of South Africa. These results and methods will be useful in future epidemiological studies and disease management of Botryosphaeriaceae from fruit trees.
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