Agustín M. Abba

The 2009/2010 Armadillo Red List Assessment

Abstract The conservation status of the 21 extant armadillo species was re-assessed by specialists of the IUCN/SSC Anteater, Sloth and Armadillo Specialist Group between December 2009 and May 2010. Information on their geographic range, population size and status, habitat and ecology, threats, and existing conservation measures was collected from the literature and personal communications. Four armadillo species were classified as Vulnerable, four as Near Threatened, and four were categorized as Data Deficient. Less than half of all armadillo species were listed as Least Concern. Virtually all assessed species are affected by hunting as well as habitat fragmentation and degradation. The populations of only two species are thought to be increasing, while those of at least seven species are in decline. Much work is still needed to ensure the long-term survival of all species. Most armadillo species occur in at least one protected area, but other conservation actions are scarce.

Distribution of extant xenarthrans (Mammalia: Xenarthra) in Argentina using species distribution models

Abstract The xenarthrans are the only group of mammals that originated in South America; there are 31 living species: six sloths, four anteaters, and 21 armadillos. In Argentina, 18 species of xenarthrans were cited. The objectives of this study were to compile the existing information on the distribution of the xenarthrans of Argentina, to use species distribution models to map the potential distribution of these species, and to assess patterns of species richness of this important group of mammals. We obtained a total of 975 records corresponding to 706 different collecting localities from Argentina. We generated species distribution models for 15 of the 18 species present in the country. Virtually all of Argentina is occupied by xenarthrans. The highest richness of species is in the north and northeast of the country in the humid and arid Chaco, probably in relation with the mosaic of ecosystems recorded in these regions. These ecoregions have different degrees of habitat degradation and continues to be a major threat for the viability of the xenarthrans occurring there. The information given in this contribution is an input to clarify occurrence and distribution of this group of mammals.

The 2010 Anteater Red List Assessment

Abstract The IUCN/SSC Anteater, Sloth and Armadillo Specialist Group re-assessed the conservation status of the four extant anteater species in May 2010. Three species maintained their Least Concern status. Myrmecophaga tridactyla was listed as Vulnerable due to an estimated reduction in population size of at least 30%. The isolated population of Cyclopes didactylus that inhabits the Atlantic forest of coastal northeastern Brazil was assessed separately for the first time due to its separation from the main population by over 1000 km. Although its habitat has been severely reduced, it was classified as Data Deficient due to the lack of scientific data. The main threats to the long-term survival of anteaters is habitat degradation and fragmentation, wildfires, traffic accidents, hunting, and their capture for illegal trade and maintenance as pets. Education programs are in place for three species. Basic questions on the taxonomy, population dynamics, life history, and how hunting and extraction of wild individuals affects anteater populations still remain unresolved.

Historia natural del piche llorón Chaetophractus vellerosus (Mammalia: Xenarthra: Dasypodidae)

Fil: Abba, Agustin Manuel. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina

Impactos de la transformación agropecuaria sobre la biodiversidad en la provincia de Buenos Aires

Impacts of agricultural transformation on biodiversity in the province of Buenos Aires, Argentina. Agricultural practices have a series of profound transformations on natural systems. Similarly to what have happened in other regions, the introduction of agro-ecosystems in the Pampas of the province of Buenos Aires in Central Argentina has substantially modified its structure and functioning, with consequent changes for regional biodiversity. In this paper we summarize the main findings of the studies conducted by our research group regarding the impact of agricultural practices on biodiversity in Buenos Aires province during the last 2-3 decades, namely: 1) agriculturization has resulted in detectable changes in the abundance and distribu- tion of many vertebrate species, particularly in retractions of species of birds and mammals associated with grass- lands, highlighting the need to maintain pastoral landscapes with large areas of natural grasslands, as several endangered species are found exclusively in such landscapes, 2) in highly fragmented agricultural landscapes, maintenance of natural vegetation along roadsides, embankments and fences helps to retain a significant frac- tion of wildlife in agroecosystems, 3) the coexistence of Pampas deer (Ozotoceros bezoarticus) and cattle is possible under rotational grazing systems and / or under low stocking rate schemes and 4) the presence of trees is a limit- ing factor of the abundance of pest birds (pigeons and parrots) in the province of Buenos Aires, which raises the possibility of a proper management of these species depending on the density and type of trees to be planted.

Systematics of hairy armadillos and the taxonomic status of the Andean hairy armadillo (Chaetophractus nationi)

Hairy armadillos constitute an ecologically homogeneous and morphologically similar group with currently 5 species classified in the subfamily Euphractinae. Among them, the Andean hairy armadillo Chaetophractus nationi (Xenarthra, Cingulata, Dasypodidae) is a small, endangered armadillo that has long been suspected to represent a high-altitude variant of Chaetophractus vellerosus. Here, we report the 1st phylogenetic systematics assessment of hairy armadillos using morphological and molecular analyses of all described species with focus on the status of the Andean hairy armadillo. Multivariate analyses of shape variation based on 3-dimensional landmark coordinates of skulls allowed a clear differentiation of each species with the exception of C. vellerosus and C. nationi, within which only a latitudinal and/or altitudinal gradient in size was apparent. Moreover, analyses of mitochondrial DNA control region (D-loop) revealed a single C. nationi haplotype that appeared to be identical with a C. vellerosus haplotype from Argentina. Identical sequences in C. vellerosus and C. nationi were also observed for 3 of the 5 non-coding nuclear markers investigated. Based on these data, we propose that C. nationi should be considered as a synonym of C. vellerosus. However, this taxonomic change should not preclude the protection of the high-altitude Bolivian populations that are steadily declining because of their overexploitation for traditional purposes. Finally, phylogenetic analyses of euphractine armadillos based on a combination of 6 non-coding nuclear markers and 2 nuclear exons suggest the paraphyly of the genus Chaetophractus, with C. vellerosus being more closely related to Zaedyus pichiy than to C. villosus.

Distribution and use of burrows and tunnels ofChaetophractus villosus (Mammalia, Xenarthra) in the eastern Argentinean pampas

Burrows and tunnels built byChaetophractus villosus (Desmarest, 1804) (hairy armadillo) were studied in a farming area located in the Argentinean pampas, Buenos Aires Province, Argentina. Fifty-six structures were selected and carefully excavated for this study. Data on diameter, form, and orientation of the entrance, angle, length, and depth of the galleries, and spatial distribution of the structures were recorded. The structures were separated into two types: simple and complex, both located in high terrain. Simple structures are shorter than complex ones and are built when animals are in search of food or as temporary shelters. Complex structures are built as home burrows. The orientation of the entrances of both kinds of burrows is related to the prevalent wind direction.

Research on armadillos: a review and prospectus

A detailed analysis of 1,039 scientific studies of extant armadillos (Xenarthra: Cingulata, Dasypodidae) published in the last 25 years (1989–2013) revealed substantial biases in coverage, including taxonomically, the locales where field studies were conducted, and in the topics investigated. Examination of the number of other publications that cited each paper revealed that 470 (45%) papers had been cited no more than 10 times, 249 (24%) had never been cited, and 112 (11%) were not even found in the Google Scholar database. The most heavily cited papers were molecular phylogenetic analyses that often used tissues from one or more species of armadillo but were not about the animals per se. Thus, it appears that research on armadillos is plagued by numerous gaps in coverage and is not reaching a wide audience. These data indicate obvious opportunities for future research. In addition, recent findings suggest that even relatively well-studied phenomena may require reexamination. Here, we review recent advances in the study of armadillos and highlight promising areas for future work. One critical need is for a thorough systematic revision of Dasypodidae to be completed. This will make it possible to prioritize those species and populations most in need of study. Additionally, more long-term field studies of populations of marked individuals are required. Although there are many important and interesting questions waiting to be answered, the small number of researchers currently conducting studies of armadillos, particularly in the wild, means that progress will be slow.

Nuevos aportes a la historia natural de la mulita pampeana Dasypus hybridus (Mammalia, Dasypodidae)

This contribution presents new data about the natural history of the Dasypus hybridus (Desmarest, 1804) (Mammalia, Xenarthra, Dasypodidae). A seasonal monitoring using the capture and release method was performed over the course of three years in a 100 ha of four cattle farms in the Buenos Aires province, Argentina. Data were collected on food habits, space and time use, behavior, thermoregulation, population data, and morphology. A total of 71 captures were made. The main food items recorded were plant matter, ants and coleopterans, and did not occur seasonal differences in food habits. Dasypus hybridus concentred their activities during daytime, and were recorded a low frequency of activities during cold seasons (fall and winter). The long-nosed armadillo prefer humid soils and grasslands with high vegetation cover, and selected forest to refuge. The southern long-nosed armadillo were asocial. Rectal temperature was positively correlated with environmental temperature. The sex proportion was near to one, and no sexual dimorphism was observed. In general, the results of this study are in agreement with previous observations of other species of the same genera, but is necessary to highlight the trend observed in food habits and thermoregulatory strategy. This work provides new information about different aspects of a poor studied species that occur in a habitat subjected to high pressure to modification and use.

Zaedyus pichiy (Cingulata: Dasypodidae)

Abstract: Zaedyus pichiy (Desmarest, 1804) is a small armadillo commonly known as pichi. Like all armadillos, it bears a carapace of ossified dermal scutes covered by epidermal scales, but it is the only species that bears marginal scutes with sharply pointed apices. This diurnal, semifossorial species inhabits xeric shrublands and grasslands on sandy soils from central Argentina and Chile south to the Straits of Magellan. Z. pichiy has opportunistic omnivorous food habits and is the only xenarthran known to enter hibernation. It is listed as “Near Threatened” by the International Union for Conservation of Nature and Natural Resources; it is mainly threatened by humans who hunt it for food or sport.