Abstract The reproduction is one of the main events in the life of an organism, and anurans stand out among vertebrates because of the diversity of their reproductive strategies. We studied the reproduction of two syntopic species, Physalaemus aff. albonotatus and P. santafecinus, and comparatively described their reproductive activity pattern, advertisement calls, calling sites, daily calling activity, amplexus behavior, foam nests, and microhabitats in foam nests. In regards to the reproductive activity pattern, both species were defined as prolonged breeders. However, P. santafecinus exhibited a behavior like explosive breeders: it had a faster reproductive response against rains than P. aff. albonotatus. The calling activity was restricted exclusively to night hours in P. santafecinus, whereas P. aff. albonotatus called during both night and day. The advertisement calls of both species showed a rich harmonic structure, and were characterized by a bimodal harmonic dominance. The species differed significantly in microhabitat calling sites, foam nests, and microhabitats in foam nests. Namely, P. santafecinus frequently called and constructed its nests in sites more exposed than those of P. aff. albonotatus. The general differences in reproductive behaviors observed between the species principally agree with their different reproductive activity patterns.

Abstract Two dimensions of the ecological niche (diet and habitat) of a snake assemblage from an endemic rich area in east-central Argentina, the Sierras de Ventania mountain chain, were analyzed. Field data collection was performed in 15-week study periods between 2010 and 2014. Snakes were hand-captured using transect surveys. Field observations on diet were analyzed together with stomach content data from museum specimens. Our results supported the partitioning of the snake assemblage by both habitat use and diet into at least three functional groups: species restricted to microhabitats under rocks and with a diet composed exclusively of ants (Epictia australis); species found mostly in stream microhabitats and feeding mainly upon anurans (Erythrolamprus poecilogyrus and Lygophis elegantissimus); and species found mostly in grassland microhabitats, with specialized diets of terrestrial prey items (Philodryas patagoniensis and Bothrops alternatus). Consistent with previous work, diet was more important than habitat in explaining ecological niche partitioning of this snake assemblage. Our results showed that high overlap values of microhabitat use were compensated by low overlap values of the trophic niche dimension, thus matching the traditional complementary niches hypothesis.

After more than a decade from the first red list of threatened herpetofauna proposal by the Asociación Herpetológica Argentina (2000), we re-categorized snakes from new taxonomic, biogeographical and bio-ecological information as well as methodological changes in the former evaluation. Through the participation of 18 specialists from all over Argentina, 136 taxa of snakes (130 in the previous) were re-evaluated including several taxonomic changes (8 new taxa added to Argentina, and 2 sinonimies). The results were the inclusion of 49 species in the red list (5 Endangered, 17 Threatened, 27 Vulnerable), 15 Insufficiently Known and 72 Not Threatened. Compared to the former categorization of the AHA: one taxon descended from Vulnerable to Not Threatened, 11 Not Threatened and 4 Insufficiently Known were elevated to different categories of threat, 7 taxa were elevated from Endangered to Vulnerable, one from Vulnerable to Endangered. From the 8 taxa not evaluated in 2000, one categorized Not Threatened, 4 Insufficiently Known, one Vulnerable, and 2 Threatened. These changes are the result of: (1) increased systematic, biogeographical and bio- ecological information available for the evaluation, (2) Changes in human pressures on the species or their habitats, (3) methodological changes that included recommendations to apply concepts, discussion and consensus among specialists and the analysis of uncertainties.

A más de una década de la primera Lista Roja de herpetofauna amenazada propuesta por la Asociación Herpetológica Argentina (AHA 2000), se recategorizaron las serpientes a partir de nueva información taxonómica, biogeográfica y bio-ecológica, además de modificaciones metodológicas respecto a la evaluación anterior. Mediante la participación de 18 especialistas de toda la Argentina se reevaluaron 136 taxones de serpientes (130 en la anterior) incluyendo varios cambios taxonómicos (8 taxones nuevos para Argentina y 2 sinonimizados), obteniéndose como resultado la inclusión de 49 especies en la lista roja (5 En Peligro, 17 Amenazadas, 27 Vulnerables), 15 Insuficientemente Conocidas y 72 No Amenazadas. En relación con la categorización anterior de la AHA: un taxón descendió de Vulnerable a No Amenazado, 11 No amenazados y 4 Insuficientemente Conocidos fueron elevados a distintas categorías de amenaza, 7 taxones Vulnerables fueron elevados a Amenazados, un taxón fue elevado de Amenazado a En Peligro. De 8 taxones no evaluados en 2000, uno categorizó No Amenazado, 4 Insuficientemente Conocidos, uno Vulnerable y 2 Amenazados. Estas modificaciones son el resultado de: (1) Mayor información sistemática, biogeográfica y bio-ecológica disponible para la evaluación; (2) Cambios en cuanto a las presiones antrópicas sobre las especies o sus hábitats; (3) Modificaciones metodológicas que incluyeron instructivos para aplicar los conceptos, la discusión y consenso entre especialistas y el análisis de las incertidumbres.