Black-headed bushmaster

Lachesis melanocephala

SUBFAMILY

Crotalinae

TAXONOMY

Lachesis melanocephala Solórzano and Cerdas, 1986, 5.6 mi (9 km) north of Ciudad Neily, Puntarenas Province, Costa Rica.

OTHER COMMON NAMES

German: Schwarzkopf-Buschmeister; Spanish: Cascabel muda, matabuey, plato y negro.

PHYSICAL CHARACTERISTICS

This extremely large snake commonly reaches 6.6 ft (2 m), and specimens of 7.5–7.9 ft (2.3–2.4 m) have been documented. The snout is distinctively rounded. A vertebral ridge is present; and the dorsal scales bear tubercular keels such that the body appears rough. The dorsal ground color is yellow, tan, or brown with black diamond-shaped blotches. The top of the head is black. Seven to nine supralabial, 209–222 ventral, 35–54 subcaudal, and 36–41 midbody scale rows have been recorded for this species.

DISTRIBUTION

The species occurs in southwestern Costa Rica and possibly adjacent parts of Panama.

HABITAT

It inhabits lowland wet and moist forest and premontane wet forest.

BEHAVIOR

The black-headed bushmaster is terrestrial. Some use rodent or armadillo burrows as refuges. It may vibrate the tail when disturbed.

FEEDING ECOLOGY AND DIET

This species forages by ambush. Rodents and marsupials are probably the main prey.

REPRODUCTIVE BIOLOGY

Females may lay up to 16 eggs; two clutches laid in captivity included nine and 13 eggs, respectively. Females remain with the eggs until they hatch.

CONSERVATION STATUS

Although not listed by the IUCN, this species is relatively uncommon and has a restricted distribution.

SIGNIFICANCE TO HUMANS

The black-headed bushmaster is dangerously venomous; any bite should be considered life-threatening. Other species of bushmaster (e.g., Lachesis muta) are used as food. Bushmasters, in general, feature prominently in forest lore, probably owing mainly to their formidable size and lethal venom.