Yarará grande, Wutu, Crossed pit viper
The Urutu (Bothrops alternatus) is a highly venomous pit viper species found in South America. Within its range, it is an important cause of snakebite. The common names of this snake urutu and wutu refer to the crescent markings on its body.
No
NocturnalNocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal",...
Ca
CarnivoreA carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of a...
Pr
PrecocialPrecocial species are those in which the young are relatively mature and mobile from the moment of birth or hatching. Precocial species are normall...
Te
TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
Ov
OvoviviparousOvoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous an...
Pr
PredatorPredators are animals that kill and eat other organisms, their prey. Predators may actively search for or pursue prey or wait for it, often conceal...
Hi
Highly venomousHighly venomous animals are able to produce the most toxic venom which is considered to be one of the most debilitating and potentially deadly.
No
Not a migrantAnimals that do not make seasonal movements and stay in their native home ranges all year round are called not migrants or residents.
U
starts withThe urutu is a large and stout snake, with females being significantly longer and heavier than males. The scalation includes 25-35 rows of dorsal scales at midbody, 155-183/164-190 ventral scales in males/females, and 38-53/30-44 subcaudal scales in males/females. On the head, there are 8-13 strongly keeled intersupraocular scales, 8-10 supralabial scales, none of which are fused with the prelacunal, and 12-14 sublabial scales. The color pattern is exceedingly variable. The ground color may be brown, tan, or gray, sometimes with an olive cast. The top of the head is usually chocolate brown to almost black with a range of transverse and longitudinal tan to white markings. On the body, there is a series of 22-28 dorsolateral markings that are chocolate brown to black in color and boldly bordered in cream or white. Along the vertebral line, these markings may either oppose or alternate. Each marking is widened and invaded from underneath by the paler ground color so that it either looks like a cross, encloses a darker blotch, or divides the marking into three parts to give it the shape of a headphone. On the tail, the pattern fuses to form a zigzag pattern. In some specimens, the pattern is so concentrated that there is no difference in color between the markings and the interspaces. The ventral surface includes a dark brown to black stripe that starts at the neck and runs down to the tail tip.
Urutu snakes are found in southeastern Brazil, Paraguay, Uruguay, and northern Argentina. In Argentina, they occur in the provinces of Buenos Aires, Catamarca, Córdoba, Corrientes, Chaco, Entre Ríos, Formosa, La Pampa, Misiones, San Luis, Santa Fe, Santiago del Estero, and Tucumán. These snakes inhabit tropical and semitropical forests, as well as temperate deciduous forests. They are usually absent in dry environments and prefer marshes, low-lying swamps, riparian zones, and other humid habitats. They are also common in sugarcane plantations. They are found in a variety of habitats depending on the latitude, including open fields and rocky areas in the Sierra de Achiras in Córdoba and the Sierra de la Ventana in Buenos Aires in Argentina, fluvial areas, grasslands, and cerrado. They are usually absent in dry environments.
Urutu snakes are very aggressive. They are terrestrial but are capable of climbing. They hunt during the night using the heat-sensing organs on each side of their head to locate potential prey.
An important cause of snakebite within its range, bites are rarely fatal but frequently cause severe local tissue damage. Although it was found that the urutu had a reputation for being one of the most venomous snakes in Brazil, its bite "said to occasion almost certain death", the statistics tell a different story. The median lethal dose of this species in Brazil varies according to the location, from 2.2 mg/kg (3.5×10−5 oz/lb) to 4.1 mg/kg (6.6×10−5 oz/lb).
Urutu snakes are carnivores. They mainly prey on mammals, lizards, frogs, birds, and other snakes.
Females, depending on their size, give birth to varying numbers of live young. Captive females are known to give birth to 3-12 young. Neonates are identical to the adults, except that they are more brightly colored. They are capable of a venomous strike immediately when they are born.
