Boiruna maculata (Boulenger, 1896)

De Alencar, Arília Aiarsa Laura R. V. & Martins, Marcio, 2013, Natural History Of Pseudoboine Snakes, Papéis Avulsos de Zoologia 53 (19), pp. 261-283 : 262-263

Boiruna maculata (Boulenger, 1896)

Distribution: Boiruna maculata is distributed from central Brazil to central Argentina with records in Uruguay ( Abalos et al., 1964; Lema, 1994; Zaher, 1996; Achaval & Olmos, 1997; Nogueira, 2001; Leynaud & Bucher, 2005; Briguera et al., 2006; Gallardo & Scrocchi, 2006; Kacoliris et al., 2006b; Scott Jr. et al., 2006; Hartmann & Giasson, 2008; Ghizoni et al., 2009). It appears to be a rare snake in Central Brazil ( França & Araújo, 2006).

Habitat and time of activity: Only scattered ecological information exists about this large pseudoboine (maximum SVL = 1919 mm, female; this study). It seems to inhabit savannas and forests ( Zaher, 1996; Leynaud & Bucher, 2005; França et al., 2006; Condez et al., 2009), and can also be found in disturbed areas ( Sawaya et al., 2008; R. Bérnils, unpublished data; P. Hartmann, unpublished data; C. Strüssmann, unpublished data). It is apparently a terrestrial species (N = 5; Gallardo et al., 2006; R. Bérnils, unpublished data; P. Hartmann, unpublished data; C. Strüssmann, unpublished data), although there is one arboreal record (Gallardo et al., 2006). Data on the time of activity of this species is very scarce. There are two observations of B. maculata in activity during the night (Gallardo et al., 2006; P. Hartmann, unpublished data), one at twilight ( Hartmann & Giasson, 2008) and one active during the day ( R. Machado & R. Bérnils, unpublished data).

Feeding: Boiruna maculata is a diet generalist that feeds primarily on snakes (N = 18; two Atractus sp. , one Liophis almadensis , Liophys typhlus, Lystrophis dobignyi, Oxyrhopus petola , one Sibynomorphus sp. ), but also on birds (N = 5; Gallus gallus ), small mammals (N = 5; Akodon serrensis ), lizards (N = 3; one scincid, one Ameiva ameiva , one Tropidurus torquatus ), and fish (one Symbranchus marmoratus ) ( Lema et al., 1983; Pinto & Lema, 2002; Gallardo et al., 2006; Hartmann & Giasson, 2008; this study).

Reproduction: Clutch size varies from four to 15 eggs (mean = 7.9 eggs, N = 13; Vitt & Vangilder, 1983; Pizzatto, 2005; Gallardo & Scrocchi, 2006; Scott Jr. et al., 2006; this study) and this species presents a continuous reproductive cycle ( Pizzatto, 2005). Pizzatto (2005) found a significant sexual size dimorphism in snout-vent length for B. maculata , where females attain larger body size than males. The smallest mature female was 974 mm SVL (this study) and the smallest mature male was 745 mm SVL ( Pizzatto, 2005).

Defense: When handled, B. maculata rarely tries to bite ( Achaval & Olmos, 1997).