Fig. 4.77 Lachesis muta muta.

Distribution

From southern Nicaragua to eastern Peru and northern Brazil. Trinidad. Separate population on the east coast of Brazil. See link "Distribution" at the top of the page for detailed information.

  Map 62 Lachesis spp.

For details see 'Distribution tables'

Biology

With a length of up to more than 3.6 m, this is the largest species of the Viperidae. Exceedingly sturdy body with distinct, wide, rounded head. Eyes comparatively small. Basic colouring brownish, at times with shades of red or yellow. Rows of dark triangles along both sides of the spine which taper towards the belly and have a lighter patch in the centre.

Active in the evening and at night. A fairly uncommon species whose habitat is primary rainforest, remote from civilisation.

If the Bushmaster encounters humans during the day, it is said to be relatively unaggressive. During its nocturnal phase of activity, however, it shows marked defensive behaviour and is easily provoked into striking. When provoked, it inflates its neck and vibrates the tip of its tail. Populations on the Pacific Coast of Costa Rica are said to be aggressive at any time of the day or night.

Risk

Because these snakes live remote from civilisation, accidents are rare in many regions. Envenoming should be taken seriously and can end fatally.

These snakes account for fewer than 3% of the total number of recorded snakebites in Brazil (Ribeiro 1990b). There is an unusually high incidence of bites in Ecuador, where in a series of identified snakebites, around 40% were due to the Bushmaster (Kerrigan 1991).

Literature (biological)

Bolanos 1984, Campbell and Lamar 1989, 2004, Chippaux 1986, Hamdan et al. 2024, Lancini 1986, Pérez-Santos and Moreno 1988, Villa 1984