Valeria Ojeda

Highway Network Expansion in Andean Patagonia: a Warning Notice From Rufous-legged Owls

Abstract As part of the economic and population growth of Patagonia, several dust/gravel roads crossing well preserved Andean forests are being converted into paved highways. The potential effects of these changes on forest wildlife have been little studied. The Rufous-legged Owl (Strix rufipes) was dominant among road-killed birds in our survey of a 27-km section of highway running through forests of Nahuel Huapi National Park, in Argentine Patagonia. Fatalities were not evenly distributed along the surveyed length of the road, so we investigated whether landscape features, roadside slope on both sides of the highway, demography, and/or season explained the aggregation pattern. Patterns of distribution of the road-killed owls were explained by owl abundance and age-class, time of year, and hour, and were weakly related to canopy closure; roadside slope on both sides was unrelated to abundance of fatalities. Traffic-related deaths were likely the primary cause of non-natural mortality of Rufous-legged Owls (especially for young individuals) in the study area. Examination of carcasses indicated that most owls were killed by turbulence behind large vehicles and that deaths occurred early in the night. Semitrailer trucks capable of carrying large loads, which peak in numbers between dusk and midnight, likely caused most fatalities. A way to reduce owl mortality could be to schedule truck traffic outside the hours when owls are most active at hunting around paved roads crossing natural forests, at least during late winter and spring seasons. Because transportation networks encourage future development that will affect the environment in a variety of ways, it is critical to retain roadless and near-roadless (i.e., having only dirt or gravel roads with slow-moving traffic) portions of the southern Andes to preserve their natural landscapes.

Can the intake of antiparasitic secondary metabolites explain the low prevalence of hemoparasites among wild Psittaciformes

BackgroundParasites 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.ResultsWe 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.ConclusionsThe 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.

First presence records of Nothofagus nitida (Nothofagaceae) in Argentina and estimation of its potential distribution area

Nothofagus nitida es una especie arborea siempreverde considerada endemica de los bosques humedos del sur de Chile. En este estudio, se informa el hallazgo de individuos de N. nitida al este de Los Andes en Argentina, ampliandose su area de distribucion geografica potencial, hasta ahora documentada solo para zonas humedas al oeste de la Cordillera de Los Andes, en Chile. Las nuevas localidades corresponden al Brazo Sur del Lago Menendez a orillas de los rios Alerce y del Paso Viejo, en el Parque Nacional Los Alerces, Provincia de Chubut, Argentina. Se tomaron muestras de follaje fresco de cinco individuos que fueron considerados N. nitida putativos a base de la morfologia foliar y corteza. Se extrajo ADN, se amplifico mediante PCR y se secuencio de manera automatica la region ITS del ADN nuclear que permite identificar las distintas especies del subgenero Nothofagus. Las secuencias de ADN obtenidas de cuatro individuos correspondieron de manera inequivoca a N. nitida. Por otro lado, se realizo un modelado de la distribucion de la especie que mostro otras areas potenciales de ocurrencia en Argentina. Este hallazgo amerita la realizacion de esfuerzos para su busqueda en otras localidades al este de Los Andes, utilizando como herramienta los mapas de distribucion potencial a fin de determinar su distribucion y utilizar marcadores geneticos para confirmar su presencia.*Autor de correspondencia: a Universidad Nacional del Comahue, INIBIOMA-CONICET, Quintral 1250, 8400 Bariloche, Río Negro, Argentina, tel.: +54 294 4428505 Int. 110, andrea.premoli@gmail.com b Guardaparque (R), 9211 Lago Puelo, Chubut, Argentina. c Cuerpo de Guardaparques, Parque Nacional Los Alerces, Administración de Parques Nacionales, 9201 Villa Futalaufquen, Chubut, Argentina. d Universidad Nacional de Córdoba, Instituto Multidisciplinario de Biología Vegetal (IMBIV)-CONICET, Córdoba, Argentina. e Universidad Nacional del Comahue, Departamento de Zoología, Bariloche, Río Negro, Argentina.