A classification scheme for mixed-species bird flocks.

The literature on mixed-species flocks references a wide variety of bird associations. These studies, however, have used an array of unstructured characteristics to describe flocks, ranging from the temporal occurrence of flocking to the identity and behavioural features of constituent members, with little consensus on which key traits define and characterize a mixed-species flock. Moreover, although most studies report species-specific roles, there is no clear consensus about what these roles signify nor how to define them.

Predation by invasive rainbow trout on the critically endangered Pehuenche spiny-chest frog.

The Pehuenche spiny-chest frog Alsodes pehuenche is an endemic species from the Andes of Argentina and Chile and is considered to be critically endangered. Its population has been declining over the past 10 years, principally as a consequence of the paving of a road that crosses the streams the frog inhabits. Until recently, exotic fish species had not been recorded in these streams.

Plasma Cholinesterase Activity in Wild Birds from Undisturbed Woodlands in the Central Monte Desert.

Plasma cholinesterase activity is a biomarker sensitive to the effect of organophosphate and carbamate pesticides, and its enzymatic levels have been previously unknown for most of the wild birds analyzed in the present study. Our objectives were to establish plasma acetylcholinesterase levels in songbirds of 2 undisturbed sites in the central Monte Desert (Argentina). We also examined the influence on cholinesterase activity of age, sex, body condition, feeding and migratory habits, and species.

Rosácea infantil.

Background: Rosacea is a chronic inflammatory skin condition that usually occurs in adults and rarely has been reported in children, although both subtypes share the same clinical characteristics.

Case Report: A 10-year-old female presented dermostosis on the face, affecting cheeks and nose, characterized by erythema, papules, pustules, scars of two years of evolution, as well as bilateral conjunctivitis, blepharitis and corneal opacity. She referred recurrent exacerbations and partial remission of cutaneous lesions and ocular symptoms related to sun exposure.

Erythrocyte micronucleus cytome assay of 17 wild bird species from the central Monte desert, Argentina.

Birds have the potential to be considered valuable bioindicators of the quality of ecosystems and the environmental impact of pollutants. The aims of this study were to determine the micronuclei frequency and other nuclear abnormalities in erythrocytes by analyzing a wild bird community from central Monte desert (Argentina) and to clarify if there were any differences among certain species. Frequencies of nuclear abnormalities were determined in 73 wild birds belonging to 17 species and two orders (Passeriformes and Columbiformes).