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New records are provided for two species of bat from Argentina belonging to the family Vespertilionidae, Histiotus montanus and the recently described Neoeptesicus ulapesensis. These data extend the range of both species incorporating them into two new provinces. One record comes from the revision of a specimen deposited in the Colección Mamíferos Lillo for more than six decades, highlighting the importance of biological collections for studying the systematics and distribution of species. [ABSTRACT FROM AUTHOR]

The present work summarizes 10 years of field observations of an exurban squamate assemblage occupying a 1200 ha patch in the suburbs of La Plata City (Los Porteños, Buenos Aires, Argentina). Crossed by two streams (Martin and Carnaval), the area is characterized by intensive horticulture and floriculture, poultry and pig farming, exhibits a low housing density (1 house/ha), and the roads are largely unpaved. This area is under stress due to continuous expansion of the neighboring city in detriment of rural areas, determining a stressing environmental scenario. Field data were complemented and contextualized with museum records of the squamates present in the area and in neighboring departments of La Plata. The field-based species list of squamates from Los Porteños comprises one amphisbaenian (Amphisbaena darwinii = 26 specimens), five snakes (Paraphimophis rustica = 24, Xenodon dorbignyi = 6, Erythrolamprus poecilogyrus = 3, Erythrolamprus semiaureus = 2, Lygophis anomalus = 1), and one lizard (Salvator merianae = 11). The number of species of squamates in Los Porteños was higher than the expected compared with the species from surrounding areas. Fossorial, nocturnal and generalist species were the most abundant in Los Porteños. These urban adapter species lack dietary constraints and their living habits minimize the encounters with humans, who commonly kill them. [ABSTRACT FROM AUTHOR]

The present study characterizes a population of Hydromedusa tectifera in a human-disturbed stream in Buenos Aires province, Argentina. We analyzed the variation of abundance, sex ratio, body condition index, and size class distribution across 3 sections of the Rodriguez stream with different degrees of urbanization regarding house density (null, low, and high) along the stream margins. Fieldwork was carried out from March 2017 to January 2018. Turtles were caught manually, and the following variables were recorded: site, transect and margin, sex, straight carapace length, and weight. We found 109 H. tectifera individuals (56 males, 46 females, and 7 hatchlings) with a balanced sex ratio and body condition index that did not vary among sites. Most turtles were caught at the site with greatest urbanization degree. However, our results showed no significant differences in the number of turtles caught among stream sites. Regarding size class distributions, the population consists largely of medium-sized to large adult turtles (150–250 mm). The present study demonstrates that the moderate urbanization degree occurring along the Rodriguez stream seems not to have negative impact on the studied population of H. tectifera. Some of the topics highlighted here constitute a first step to understanding how urbanization impacts this species. In any case, we suggest that a periodic monitoring program of the studied population is necessary in order to monitor the studied parameters and include new ones, such as habitat requirements, reproduction sites, and food quality, among others, that would probably be useful for population management to achieve better integration between the city and the turtles living there. [ABSTRACT FROM AUTHOR]

1. The fruit-tracking hypothesis predicts spatiotemporal links between changes in the abundance of fruit-eating birds and the abundance of their fleshy-fruit resources. 2. While the spatial scale of plant-frugivore interactions has been explored to understand mismatches between observed and expected fruit-frugivore patterns, methodological issues such as the consequences of measuring fruit and frugivore abundance rather than fruit availability and fruit consumption have not been evaluated. 3. Here, we explored whether predicted fruit-frugivore spatiotemporal links can be captured with higher accuracy by proximate measurements of interaction strength. We used a 6-ha grided plot in an Andean subtropical forest to study the link between (i) fruit and fruit-eating bird abundances; (ii) fruit availability and frequency of fruit consumption; and (iii) covariation between frugivore abundance and frequency of frugivory. We evaluated these links for the entire frugivore assemblage and for the four most important species using data gathered bimonthly along a 2-year period. 4. Fleshy-fruit availability and abundance varied sharply temporally and were patchily distributed in mosaics that differed in fruit quantity. Fruit availability and abundance also varied along spatial gradients extended over the whole study plot. We found a strong response of the entire frugivorous bird assemblage to fruit availability over time, and a weakly significant relationship over space at the local scale. The main frugivore species widely differed in their responses to changes in fruit abundance in such a way that response at the assemblage level cannot be seen as the sum of individual responses of each species. Our results suggest that fruit tracking in frugivorous-insectivorous birds may be largely explained by species-specific responses to changes in the availability of fruits and alternative resources. 5. In agreement with our prediction, more accurate measurements of interaction strength described fruit-frugivore relationships better than traditional measurements. Moreover, we show that covariation between frugivore abundance, frequency of fruit consumption and fruit availability must be included in the fruit-tracking hypothesis framework to demonstrate (or reject) spatiotemporal fruit tracking. We propose that estimation of nutrient and energy availability in fruits could be a new frontier to understanding the forces driving foraging decisions that lead to fruit tracking., (© 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society.)