Revista Chilena de Historia Natural 84 (1): 51-64, 2011
RESEARCH ARTICLE
Natural history of the screaming hairy armadillo Chaetophractus vellerosus
(Mammalia: Xenarthra: Dasypodidae)
This contribution presents new data about the natural history of the screaming
hairy armadillo Chaetophractus vellerosus (Mammalia: Xenarthra: Dasypodidae). A seasonal monitoring using
the capture-recapture method was performed over the course of two years (2006 2008) in a 100 ha cattle farm
in the locality of Magdalena, Buenos Aires province, Argentina. Data were collected on food habits, space and
time use, behavior, thermoregulation, population data, and morphology. A total of 237 captures of 136
individuals were made. The main food items recorded were coleopterans, followed by plant matter and small
mammals; a marked drop of coleopterans in the spring diet suggested seasonal differences in food habits. In
the cold seasons, screaming hairy armadillos were mainly active at noon and during the first hours of the
afternoon, while in warm seasons their activity period shifted to the afternoon and night. The armadillos
selected sandy-calcareous soils and preferred grasslands with low vegetation and high vegetation cover. The
average home range was 2670 m<sup>2</sup>. Screaming hairy armadillos were asocial. Their
behavior varied between seasons, and they selected the forest for refuge. Rectal temperature was positively
correlated with ambient temperature and body mass. 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 C.
vellerosus populations inhabiting different environmental conditions in very distant areas from the one
monitored here. This work provides new information about different aspects of an isolated population that is
subjected to high pressure due to habitat modification and use, and is therefore facing a high extinction
risk.
Key words:
armadillos,
Buenos Aires, conservation, ecology
