estudos artísticos

info:eu-repo/semantics/publishedVersio

Nestedness of Ectoparasite-Vertebrate Host Networks

Determining the structure of ectoparasite-host networks will enable disease ecologists to better understand and predict the spread of vector-borne diseases. If these networks have consistent properties, then studying the structure of well-understood networks could lead to extrapolation of these properties to others, including those that support emerging pathogens. Borrowing a quantitative measure of network structure from studies of mutualistic relationships between plants and their pollinators, we analyzed 29 ectoparasite-vertebrate host networks—including three derived from molecular bloodmeal analysis of mosquito feeding patterns—using measures of nestedness to identify non-random interactions among species. We found significant nestedness in ectoparasite-vertebrate host lists for habitats ranging from tropical rainforests to polar environments. These networks showed non-random patterns of nesting, and did not differ significantly from published estimates of nestedness from mutualistic networks. Mutualistic and antagonistic networks appear to be organized similarly, with generalized ectoparasites interacting with hosts that attract many ectoparasites and more specialized ectoparasites usually interacting with these same “generalized” hosts. This finding has implications for understanding the network dynamics of vector-born pathogens. We suggest that nestedness (rather than random ectoparasite-host associations) can allow rapid transfer of pathogens throughout a network, and expand upon such concepts as the dilution effect, bridge vectors, and host switching in the context of nested ectoparasite-vertebrate host networks

Ecological relationships between feather mites (Acari) and wild birds of Emberizidae (Aves) in a fragment of Atlantic Forest in northeastern Brazil

The objective of this study was to investigate feather mites on birds of the Family Emberizidae, to collect data on the ecological ectoparasite-host relationship and infestation level. A sum of 94 birds of 9 species was captured at the Refúgio Ecológico Charles Darwin, Igarassú, Pernambuco, Brazil, from August 1996 to July 1997. Five genera of mites from the superfamily Analgoidea were identified: Analges Nitzsch, 1818; Mesalgoides Gaud & Atyeo, 1967; Pterodectes Robin, 1877; Proctophyllodes Robin, 1877 and Trouessartia Canestrini, 1899. Among the 94 birds examined, 92 (97,87%) were infested. Regarding the prevalence, it was observed that the genera with higher percentage were, respectively, Pterodectes (88,04%), Proctophyllodes (56,52%) and Trouessartia (45,65%)