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Abstract Background Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors, life history and immune defence. Feeding behaviour can also be relevant both through increased exposure to vectors and consumption of secondary metabolites with preventative or therapeutic effects that can reduce parasite load. However, the latter has been little investigated. Psittaciformes (parrots and cockatoos) are a good model to investigate these topics, as they are known to use biological control against ectoparasites and to feed on toxic food. We investigated the presence of avian malaria parasites (Plasmodium), intracellular haemosporidians (Haemoproteus, Leucocytozoon), unicellular flagellate protozoans (Trypanosoma) and microfilariae in 19 Psittaciformes species from a range of habitats in the Indo-Malayan, Australasian and Neotropical regions. We gathered additional data on hemoparasites in wild Psittaciformes from the literature. We considered factors that may control the presence of hemoparasites in the Psittaciformes, compiling information on diet, habitat, and climate. Furthermore, we investigated the role of diet in providing antiparasitic secondary metabolites that could be used as self-medication to reduce parasite load. Results We found hemoparasites in only two of 19 species sampled. Among them, all species that consume at least one food item known for its secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, were free from hemoparasites. In contrast, the infected parrots do not consume food items with antimalarial or even general antiparasitic properties. We found that the two infected species in this study consumed omnivorous diets. When we combined our data with data from studies previously investigating blood parasites in wild parrots, the positive relationship between omnivorous diets and hemoparasite infestation was confirmed. Individuals from open habitats were less infected than those from forests. Conclusions The consumption of food items known for their secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, as well as the higher proportion of infected species among omnivorous parrots, could explain the low prevalence of hemoparasites reported in many vertebrates.

Miridae is the largest Heteroptera family, with a tremendous worldwide economic impact, both as pests and natural enemies. Unlike most Hemiptera, herbivorous and omnivorous mirid bugs are lacerate/macerate and flush feeders, not phloem feeders. Plant responses to damage by arthropods of this feeding guild therefore occur via jasmonic acid or ethylene signaling pathways rather than the salicylic acid pathway. Moreover, unlike most other Heteroptera that lay eggs on the plant surface, mirids insert their eggs in plant tissues, resulting in oviposition injury. Similarly, regarding phytopathogenic fungi and oomycetes, a distinction should be made between biotrophic fungi (triggering the salicylic acid pathway plant response), and necrotrophic and/or hemibiotrophic fungi or oomycetes (triggering jasmonic acid or ethylene pathway plant responses). In that respect, phytopathogenic fungi or oomycetes (PFO) differ from phytopathogenic viruses and bacteria, the former being all biotrophic while the latter are theoretically hemibiotrophic. Here, for the first time, we review tripartite interactions between mirids, PFO, and crop plants. The major deliverables are as follows: Five major interaction frameworks are identified: (i) crop plant infection by PFO mechanically facilitated by prior mirid infestation; (ii) crop plant infection by PFO hampered by prior mirid infestation via crop plant signaling; (iii) crop plant infestation by mirids facilitated by prior PFO infection via crop plant signaling; (iv) crop plant infestation by mirids hampered by prior PFO infection via crop plant signaling; (v) crop plant infestation by mirids and/or infection by PFO hampered by prior mirid infestation and/or PFO infection via crop plant resource quality alteration. PFO and mirids may also occur concomitantly, favored by the same conditions, i.e., climatic or linked to endogeneous factors (e.g., redox status) in crop plant. Instances from each framework are described, and highlighted interactions are examined in view of managing mirid–PFO complexes on crop plants. [ABSTRACT FROM AUTHOR]

Edges are on the increase world-wide due to increasing fragmentation and loss of natural habitats. After formation, edges are maintained by various processes (natural vs. continued anthropogenic interventions: forestry, agriculture, urbanization) which influence the reaction of individual species to edge effects (history-based edge effect hypothesis), and this will be reflected in the diversity of assemblages. Diversity, however, is not the most appropriate indicator of the edge effect because species with different traits may respond differently to the edges. To further articulate the history-based edge effect hypothesis, we evaluated the edge effect on one of the most commonly used life-history traits, the feeding habit of ground beetles in forest edges. A meta-analysis based on 28 publications and 422 comparisons showed that natural vs. continued anthropogenic interventions as edgemaintaining processes reflected at the trait level. Abundance of herbivorous, omnivorous, and predatory ground beetle species were all higher in the natural edges than in the forest interiors, while no similar pattern occurred in edges with continued anthropogenic influence. These results suggest that structural and environmental changes at edges sustained by repeated anthropogenic influence adversely influencing ecosystem functions, with negative effects on ecosystem services like pest or weed control. [ABSTRACT FROM AUTHOR]

Se evaluó la intensidad de daño en el hábitat después del huracán Dean y su influencia en la abundancia de fauna, en la selva del centro sur del estado de Quintana Roo, México. Se situaron 20 sitios de muestreo ordenados de mayor a menor afectación. En cada sitio se realizó un muestreo de vegetación para determinar las características del hábitat y el impacto de huracán. Para la fauna, cada sitio fue muestreado para obtener índices de abundancia relativa de rastros (rastros/km). Se realizaron entrevistas con informantes clave para determinar las especies arbóreas consumidas por la fauna. El porcentaje de daño disminuyó gradualmente hasta menos de 4% a una distancia de 120 km perpendiculares al huracán. El hábitat fue relativamente homogéneo y no se encontraron diferencias entre los parámetros y atributos medidos en la vegetación, la única variable que resultó diferente fue el porcentaje de daño en los árboles. El 65% de las especies arbóreas, fueron registradas como alimento para frugívoros, herbívoros y omnívoros. En sitios de alto impacto, la abundancia de herbívoros fue menor mientras que la abundancia de omnívoros fue mayor. El daño en los árboles fue la única variable que se correlacionó negativamente con la abundancia de los herbívoros, lo cual no fue evidente con los omnívoros.We assessed the damage on the habitat after Hurricane Dean and its influence on the abundance of wildlife. We used 20 sampling sites along an area of high to low impact. At each site, vegetation sampling was conducted to determine the characteristics of habitat and the impact of hurricane Dean. For fauna, each site was sampled to obtain indices of relative tracks abundance (tracks/km). Interviews were conducted with key informants to determine which tree species were consumed by the local fauna. Damage gradually declined to less than 4% at a distance of 120 km perpendicular to the hurricane. The habitat was relatively homogeneous and no differences were found between the parameters and attributes measured in the vegetation, the only variable that differed was the percentage of trees damage. Of tree species, 65% were reported as food for frugivorous, herbivorous and omnivorous species. At high-impact sites the abundance of herbivores was lower while abundance of omnivores was higher. Damage to trees species was the only variable that negatively correlated with the abundance of herbivorous species, which was not evident with omnivorous species.

Global oil palm expansion has caused substantial ecological damage to tropical biodiversity. We quantified wild mammal richness in large oil palm plantation estates and semi-traditional oil palm smallholdings in Peninsular Malaysia. We sampled 41 plantation estates and 14 smallholdings, and used line-transect surveys coupled with semi-structured interviews to develop a database of the native mammals found in oil palm landscapes. Semi-structured interviews revealed a total of 32 mammal species, including 13 IUCN Red Listed taxa of high conservation value. Our results showed that human activity and the size of patches of remnant rainforest were important factors influencing the richness of mammal species in oil palm landscapes. More carnivorous and herbivorous species were reported in smallholdings than plantation estates, most probably as a response to greater habitat heterogeneity in smallholdings. All species, irrespective of conservation status, were more likely to be recorded in oil palm plantation estates and smallholdings that supported large areas of native forest. Our findings suggest that biodiversity conservation in oil palm landscapes will require a variety of conservation approaches. Minimizing poaching, reducing disturbance from human activity, and protecting existing forest patches appear particularly important. Strategies to promote the persistence of both high and low conservation value species should be adopted as part of a strengthened certification scheme for oil palm production. [ABSTRACT FROM AUTHOR]

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Background: Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors, life history and immune defence. Feeding behaviour can also be relevant both through increased exposure to vectors and consumption of secondary metabolites with preventative or therapeutic effects that can reduce parasite load. However, the latter has been little investigated. Psittaciformes (parrots and cockatoos) are a good model to investigate these topics, as they are known to use biological control against ectoparasites and to feed on toxic food. We investigated the presence of avian malaria parasites (Plasmodium), intracellular haemosporidians (Haemoproteus, Leucocytozoon), unicellular flagellate protozoans (Trypanosoma) and microfilariae in 19 Psittaciformes species from a range of habitats in the Indo-Malayan, Australasian and Neotropical regions. We gathered additional data on hemoparasites in wild Psittaciformes from the literature. We considered factors that may control the presence of hemoparasites in the Psittaciformes, compiling information on diet, habitat, and climate. Furthermore, we investigated the role of diet in providing antiparasitic secondary metabolites that could be used as self-medication to reduce parasite load. Results: We found hemoparasites in only two of 19 species sampled. Among them, all species that consume at least one food item known for its secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, were free from hemoparasites. In contrast, the infected parrots do not consume food items with antimalarial or even general antiparasitic properties. We found that the two infected species in this study consumed omnivorous diets. When we combined our data with data from studies previously investigating blood parasites in wild parrots, the positive relationship between omnivorous diets and hemoparasite infestation was confirmed. Individuals from open habitats were less infected than those from forests. Conclusions: The consumption of food items known for their secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, as well as the higher proportion of infected species among omnivorous parrots, could explain the low prevalence of hemoparasites reported in many vertebrates. [ABSTRACT FROM AUTHOR]