Bioacoustics of Dasypus septemcinctus hybridus

HUSBANDRY Dasypus hybridus is rarely kept in zoological institutions because it is difficult to maintain due to its excitable temperament ( Superina 2000 ). However, it has been successfully housed in pens of 6 by 2 m with concrete floor and walls. A 2 by 2 m section of the pen was covered with a roof and communicated through a door with the external part, which measured 4 by 2 m and had 1-m walls ( Ferrari et al. 1997 ). Inside the covered part of the pen, a nesting box of 1 m 3 made of bricks and a removable wooden cover allowed manipulation and observation of the animals. The box, filled with linen hay for nesting, had an L-shaped roofed entrance of 30 cm height to ensure absolute darkness ( Ferrari et al. 1997 ). For temporary visual identification, D . hybridus can be marked with various shapes and colors of reflective tape glued onto different areas of the carapace. It can be permanently marked by injecting a passive induced transponder (PIT) tag under the scapular shield, at its juncture with the neck. Also, a combination of ear notches at different locations around the periphery of each ear allows reliable identification of individuals (Abba 2008). BEHAVIOR Dasypus hybridus is diurnal, being most active between 1200 and 1500 h (Abba et al. 2011). Active all year long (Abba and Cassini 2010a), it shows reduced activity during the cold season (Abba and Cassini 2010b). Adult D. hybridus are solitary and observed in pairs only during the reproductive season (Abba et al. 2011). When threatened, D. hybridus runs to hide in an existing burrow, digs a new one, or hides in areas with high vegetative cover (see Abba et al. 2011). Vocalization is limited to a purring sound when captured animals are being handled. D. hybridus shows nest building and bathing behaviors (dipping head under water and rolling in shallow puddles) similar to those described for D. novemcinctus by Eisenberg (1961) and Taulman (1994) . One frequently observed behavior is the removal of moist plant material from the burrow, letting it dry in the sun, and then returning it as nest material to the burrow. GENETICS The diploid number (2n) for Dasypus hybridus is 64 chromosomes, consisting of 7 pairs of metacentric (2 large, 5 medium) and 24 pairs of acrocentric (4 large, 14 medium, 6 small) autosomes. The X chromosome is submetacentric and the Y is acrocentric ( Saez et al. 1964 ; Jorge and Pereira 2008). The fundamental number (FN) is 81. The genetic distinction between D. hybridus and D. novemcinctus has been determined by electrophoresis of hemoglobins and plasma proteins (Ramsey and Grigsby 1985; Ryder and Davis 1985). Gibb et al. (2016) provide mitogenomic data for a D. hybridus sample from Uruguay . The sequences are almost identical (99.3% identity) to those of a D. septemcinctus sample from Argentina but this is probably due to a misidentification of the latter animal because it originated from a potential area of sympatry of the 2 species (see Hamlett 1939 ; Abba et al. 2012 ).