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The main ecosystem in northern Patagonia, Argentina, is the Monte, a semi-desert scrubland home to a high biodiversity. Monte is the most endangered ecosystem of southern South America, with an annual rate of clearance of the native vegetation estimated at 3.7%. Here we report the results of bird surveys carried out in the province of Río Negro, northern Patagonia. We surveyed four localities mostly dominated by the Monte ecosystem, between 1986 and 2010. Three localities are Important Bird Areas (IBAs): El Cóndor, San Antonio Oeste and Meseta de Somuncurá. The fourth locality is the Paso Córdoba nature reserve. We recorded a total of 263 bird species. The highest species richness was observed at San Antonio Oeste, followed by El Cóndor. Information regarding the period of occurrence and habitats are provided for all species and localities. Additionally, we indicated the cases in which breeding behavior was observed. This information is urgently needed for the evaluation of the consequences of habitat destruction and deterioration as well as for the success of intended remediation measures.

Abstract  Glucocorticosteroids (GCs) of the hypothalam–pituitary–adrenal axis play a role in association with both stressful events and daily life processes. However, relatively little is known about the role of GCs in relation to daily and seasonal life processes in animals in the wild. In this paper, we present data on basal levels of plasma corticosterone CORT in chicks of a pelagic seabird, the thin-billed prion, Pachyptila belcheri, during two predictable changes in demands, the daily activity pattern and the preparation for fledging. By comparing chicks fed recently with unfed chicks, we test how GC levels are modified according to nutritional condition. In accordance with their nocturnal feeding rhythm, chicks had a clear daily rhythm with increased CORT secretion at night, but CORT levels during the active phase were also highly elevated in unfed chicks compared with fed chicks. Close to fledging, chicks rapidly increased basal CORT levels, and again unfed chicks had higher levels than fed chicks, although the age effect here was stronger than the effect of recent feeding. The present data thus support the hypothesis that GC levels are adjusted to life stages with predictable changes in demands, but food availability and/or internal energy stores also affect the level to which GCs increase. [ABSTRACT FROM AUTHOR]