Nidificación de tijeral (Leptasthenura aegithaloides) dentro de un nido de aguilucho (Geranoaetus polyosoma) en el desierto de Atacama de Chile

A strategy to avoid nest predation by various bird species is the selection of inaccessible sites or sites of actual danger for potential predators. In this sense nesting near a top predator may be an effective strategy to avoid nest predation, if this predator does not have a preference for eggs or nestlings of the first species. This note reports the first record of nesting by Plain-mantled Tit-Spinetail (Leptasthenura aegithaloides Kittlitz, 1830) in an active nest of the variable Hawk (Geranoaetus polyosoma Quoy & Gaimard, 1824) and the nesting of the common diuca-finch (Diuca diuca Molina, 1782) nearby, during two consecutive years, in the Atacama Desert, Chile. This occurred during the “flowering desert” phenomenon in October of 2014 and September of 2015. We discuss hypotheses that may explain this biological association and its possible ecological implications.Una estrategia utilizada por diversas especies de aves para evitar la depredación de los nidos es la selección de sitios de nidificación de difícil acceso o que representen un peligro para los potenciales depredadores de sus nidos.En este sentido la ubicación del nido en las cercanías de un depredador de potenciales depredadores del nido, puede representar una estrategia eficiente para evitar la depredación de nidos si dicho depredador no presenta una preferencia por el consumo de aves o sus huevos. En este trabajo se documenta la nidificación de una pareja de tijeral (Leptasthenura aegithaloides Kittlitz, 1830) dentro de un nido de aguilucho (Geranoaetus polyosoma Quoy & Gaimard, 1824) y la nidificación de diuca (Diuca diuca Molina, 1782) en la periferia del mismo, durante dos años consecutivos, en el desierto de Atacama, Chile. Esto se generó en el contexto de la ocurrencia del fenómeno de desierto florido en octubre del año 2014 y en septiembre del 2015, presentando hipótesis que puedan explicar esta asociación biológica y sus posibles implicancias ecológicas

NOTES ON THE DIET OF THE STRAIGHT-BILLED EARTHCREEPER (OCHETORHYNCHUS RUFICAUDUS) AND THE USE OF CITIZEN SCIENCE IMAGE REPOSITORIES

Here we report on novel information regarding the diet for the Straight-billed Earthcreeper (Ochetorynchus ruficaudus), an uncommon furnarid of arid environments of the Andes. We describe an event of food consumption in northern Chile, and complement our finding by searching freely-available citizen science repositories for photographic evidence of food items. Novel food items belonging to Coleoptera and Lepidoptera were identified. These findings contribute to our understanding of the natural history of an uncommon species, making use of opportunistic photography and freely-available and ever-increasing citizen science data

Breeding of the plain-mantled tit-spintail (<em>Leptasthenura aegithaloides</em>) in a variable hawk (<em>Geranoaetus polyosoma</em>) nest in the Atacama Desert, Chile

A strategy to avoid nest predation by various bird species is the selection of inaccessible sites or sites of actual danger for potential predators. In this sense nesting near a top predator may be an effective strategy to avoid nest predation, if this predator does not have a preference for eggs or nestlings of the first species. This note reports the first record of nesting by Plain-mantled Tit-Spinetail (Leptasthenura aegithaloides Kittlitz, 1830) in an active nest of the variable Hawk (Geranoaetus polyosoma Quoy & Gaimard, 1824) and the nesting of the common diuca-finch (Diuca diuca Molina, 1782) nearby, during two consecutive years, in the Atacama Desert, Chile. This occurred during the “flowering desert” phenomenon in October of 2014 and September of 2015. We discuss hypotheses that may explain this biological association and its possible ecological implications

Observations on the breeding behavior of the Variable Hawk (Geranoaetus polyosoma) in the Atacama Desert, Chile

Although the Variable Hawk (Geranoaetus polyosoma) is a common and broadly distributed raptor in the Neotropics, its breeding ecology is almost unknown. Using video cameras, we collected data on the parental and nestling behavior of this hawk at the early-brood rearing period from one location in the Atacama Desert of Chile. An attempt to collect data in a second nest failed due to methodological deficiencies, which suggested improvements to sampling design in future studies. As most accipitrid raptors, we found that the female performed the majority of the parental activities occurring at the nest: she fed the chicks, protected them from high solar radiation and stayed on the nest at night. Nestlings were fed with Chilean Iguana (Callopistes macullatus) and Darwin's Leaf-eared Mouse (Phyllotis darwini). We also describe some nestling behaviors. With these observations, we add information to the breeding ecology of this species and encourage the use of low-cost technology to monitor wildlife, but with certain considerations.CONICYT-PCHA/MagisterNacional/2015-2215008

Botanical Composition and Diet Quality of the Vicuñas (Vicugna vicugna Mol.) in Highland Range of Parinacota, Chile

Understanding the botanical composition of herbivores’ diets and their nutritional quality is an important question in the development of sustainable strategies for the management of natural resources. In Chilean highland vicuña-grazed grasslands, there is little information in this regard and, therefore, this study aimed to determine the year-round profile of the diet’s botanical composition and quality. In highland grasslands, on an area of 21.9 ha, continuously grazed for 3.06 VU/ha/year (18 030 S, 69 130 W; 4425 m.o.s.l), twelve feces piles were sampled monthly and were analyzed through microhistology, and the nitrogen concentration [NF,OMbasis] was determined. The botanical composition, diversity (J) and selectivity index (Ei) of the main species were estimated. Diets were composed of dry–grassland grasses (37.7%), wet–grassland grasses (36.6%), graminoids (14.3%) and forbs (10.2%). The diet diversity ranged from 0.79 (dry–winter) to 0.87 (wet–summer). The main dominant grassland species obtained negative Ei values. The annual mean value of [NF] was estimated as 1.82%, with a higher value in summer months (2.21%), which coincides with the physiological states of higher nutritional demand. The vicuñas behave like generalist ungulates, having a high degree of selectivity towards grass species, which mostly fulfill a nutritional role in subsistence and a functional role in survival, applying foraging strategies that allow them to obtain a better quality diet during the season of greatest nutritional demand.Agrarian Innovation Foundation (FIA) PIT-2008-018