Diego Procopio

The ecological role of native and introduced species in the diet of the puma Puma concolor in southern Patagonia

There is evidence for the ecological extinction of the native prey of the puma Puma concolor in north- western Argentine Patagonia. In this study we examine whether this is also the case in southern Patagonia. From 2004 to 2007 we examined the pumas diet in three protected areas and two sheep ranches in Santa Cruz province. A total of 282 puma scats were analysed. In two of the protected areas and in the ranches 60-74% of the pumas diet was native prey. Prey species were primarily guanaco Lama guanicoe, followed by Patagonian mara Dolichotis patagonum, lesser rhea Pterocnemia pennata pennata, Patagonian pichi Zaedyus pichiy and Magellanic penguin Spheniscus magellanicus. In the third protected area the main prey was the European hare Lepus euro- paeus. Our results show a clear difference in the diet of the puma in southern compared to north-western Patagonia. Large native herbivores (i.e. guanaco and lesser rhea) maintain their role as the main prey species for the puma in southern Patagonia. We suggest, therefore, that native prey could be restored to those areas of Argentine Patagonia, such as the north-west, where they are currently ecologically extinct. Facilitating native species recovery and/or restoration and applying more rigorous controls to prevent the introduction of potential alien prey species of the puma, both within and outside protected areas, needs to be evaluated as a regional strategy.

Environmental factors influencing the distribution of the Lesser Rhea (Rhea pennata pennata) in southern Patagonia

Abstract The Lesser Rhea (Rhea pennata pennata) has suffered a marked decline in numbers over recent decades, probably mainly as a result of livestock production and overhunting. Our aim was to investigate the factors that determine the distribution of Lesser Rheas in southern Patagonia and to generate a predictive regional distribution map. We surveyed 8000 km of roads and sighted 795 Lesser Rhea individuals or flocks. We also estimated environmental predictors from remotely sensed data and analysed the occurrence of Lesser Rheas in relation to these predictors. The predictors we examined were associated with four hypotheses explaining the distribution of Lesser Rheas: the persecution by ranchers, primary productivity, topography, and anthropogenic disturbance hypotheses. We built models for each hypothesis. Our results suggest that the distribution of Lesser Rheas is not negatively affected by persecution by ranchers, as the species is more abundant in areas with high stocking levels of sheep, but is positively influenced by primary productivity and negatively by the proximity of human habitation. The resulting distribution map can be used as a management tool for government agencies and highlights the conservation priorities for managing this declining and emblematic species.

Summer food habits of the Patagonian opossum, Lestodelphys halli (Thomas, 1921), in southern arid Patagonian shrub-steppes

Estudiamos la dieta estival de la comadrejita patagonica Lestodelphys halli en el sureste de la Patagonia Argentina, por medio del analisis de contenidos estomacales provenientes de animales muertos y de fecas. Encontramos una gran variedad de invertebrados (87,2% de frecuencia de ocurrencia) seguido de aves y reptiles (10,64%) tanto en estomagos como en fecas. Los frutos fueron escasos en la dieta. En cautividad, la comadrejita patagonica se alimenta fundamentalmente de roedores, reptiles, aves e invertebrados. Sin embargo, no encontramos restos de roedores en la dieta de la comadrejita. Sugerimos que la comadrejita patagonica no es un predador eficiente de roedores en estado silvestre. El alto consumo de invertebrados, reptiles, aves y frutos durante el verano, cuando estos items son abundantes, refleja el comportamiento oportunista de esta especie.

DIET OF THE AMERICAN KESTREL IN ARGENTINE PATAGONIA

Resumen Presentamos el primer analisis cuantitativo de la dieta de Falco sparverius en el sur de Argentina. Identificamos 1169 items de presas en un total de 272 egagropilas y siete restos de presas de cuatro sitios de estudio en la Patagonia. En esta area, F. sparverius se alimento principalmente de escorpiones (Bothruridae), escarabajos (Coleoptera), hormigas (Formicidae), saltamontes (Acrididae), gorgojos (Curculionidae) y roedores (Rodentia). La dieta difirio significativamente entre los sitios de estudio en terminos de la frecuencia de varios items entre las presas, pero no en terminos de la biomasa. De acuerdo a la frecuencia, los insectos conformaron la mayor parte de la dieta en la mayoria de los sitios, pero los vertebrados contribuyeron mas en terminos de biomasa.

New Patagonian species of Liolaemus (Iguania: Liolaemidae) and novelty in the lepidosis of the southernmost lizard of the world: Liolaemus magellanicus

We describe a new species within the genus Liolaemus from southeast Argentine Patagonia. This new taxon, Liolaemus yatel sp. nov., presents anatomical traits shared with the Liolaemus lineomaculatus section within the Liolaemus lineomaculatus group, especially the absence of precloacal pores in both sexes. However, Liolaemus yatel sp. nov. does not exhibit trifid dorsal scales, which is a diagnostic character of the L. lineomaculatus group. Moreover, this new species differs from other taxa of the L. lineomaculatus group in that dorsal and nuchal scales either completely lack keels or are slightly keeled. We also report, for the first time, the presence of trifid scales in Liolaemus magellanicus, another species included in the L. lineomaculatus section but constituting an independent lineage regarding the L. lineomaculatus group. The phenotypic traits of L. yatel sp. nov. and the presence of trifid scales in L. magellanicus provide additional information for the study of evolutionary relationships among the species of the L. lineomaculatus section, especially the establishment of their diagnostic character states.

Co-occurrence Patterns in Carnivorans: Correspondence Between Morphological and Ecological Characteristics of an Assemblage of Carnivorans in Patagonia

We searched for correspondence between morphology and trophic habits in an assemblage of six species of coexisting carnivorans from Patagonia to confirm the predictive power of the study of the trophic morphology as an approach to the study of resource partitioning, which is often utilized in paleontological studies. The six species were assigned to four morphoguilds and to four trophic guilds, although the species composition of both spaces was only coincident during one of the two studied time periods. The most obvious explanation for this lack of correspondence is based on the assumption that species can change from one ecological guild to another, while their relative positions in the morphospace will be fixed. Therefore, the observed lack of correspondence could be searched in the context of differences between the ecological and evolutionary scales. Although morphological specialization toward some type of diet has been corroborated in our assemblage, the inference of interactions in ecological time among species from the past from its morphology must be considered with caution.

Incubation Period of the Austral Pygmy-Owl (Glaucidium nana): A Correction

The shortest incubation periods known for an owl, 21– 24 d, have been measured in small species such as the African Scops-Owl (Otus senegalensis) and the Elf Owl (Micrathene whitneyi; Marks et al. 1999, König and Weick 2008). In an article on the biology of the Austral Pygmy-Owl (Glaucidium nana) in Chile, Jiménez and Jaksić (1989) noted that Housse (1945) gave an incubation period of 15– 17 d for that species. Housse’s (1945) information on incubation was not supported by data, however, and almost certainly was a conjecture. More recently, Ibarra et al. (2014, 2015) also reported an incubation period of 15–17 d for G. nana in Chile. However, they did not record laying and hatching dates at the same nest (J. Ibarra and T. Altamirano pers. comm.). König et al. (1999) stated that incubation lasts 26–28 d on the basis of observations of a pair of G. nana that nested in captivity (C. König pers. comm.). During their study of wild pairs that nested in boxes in Argentina (Santillán et al. 2010), MAS, DEP, and AT (unpubl. data) determined that incubation lasted from 27–29 d at three nests, which agrees closely with observations of captives by König et al. (1999), and which also is consistent with data from other species of Glaucidium such as Eurasian Pygmy-Owl (G. passerinum), Pearl-spotted Owlet (G. perlatum), Northern Pygmy-Owl (G. gnoma), and Ferruginous Pygmy-Owl (G. brasilianum; Holt and Norton 1986, König and Weick 2008). Thus, at least in species for which data are available, no species of owl is known to have an incubation period shorter than 3 wk. We thank C. König, F.M. Jaksić, J.T. Ibarra, and T.A. Altamirano for shedding light on incubation periods of Austral Pygmy-Owls.

Second record of Tadarida brasiliensis (I. Geoffroy St.-Hilaire, 1824) (Chiroptera, Molossidae) in Santa Cruz Province, Argentina

Although Tadarida brasiliensis is one of the most widely distributed species of bats in Argentina, it is nevertheless extremely scarce in Patagonia. We report a second record of T. brasiliensis for Santa Cruz province, which fills a gap in the geographical distribution of this species in that province and is also the third southernmost record for the species and for any molossid bat in the world.