Military Ground Snake

The military ground snake (Erythrolamprus miliaris) is a species of snake in the subfamily Dipsadinae of the family Colubridae. The species is endemic to South America.

Common names

South American common names for Erythrolamprus miliaris include cobra-d'água (water snake) and cobra-lisa (smooth snake) in Portuguese, and simply culebra (snake) in Spanish.

Taxonomy

Erythrolamprus miliaris was originally described as Coluber miliaris by Carl Linnaeus in 1758.

Erythrolamprus miliaris belongs to the genus Erythrolamprus, which contains over 50 species. The genus Erythrolamprus belongs to the subfamily Dipsadinae, which is sometimes referred to as the family Dipsadidae. The relationships of Erythrolamprus species located in northern South America can be shown in the cladogram below, based on molecular DNA analysis:

Subspecies

Five subspecies are recognized, including the nominotypical subspecies.

Erythrolamprus miliaris amazonicus (Dunn, 1922)

Erythrolamprus miliaris chrysostomus (Cope, 1868)

Erythrolamprus miliaris merremi (Wied, 1821)

Erythrolamprus miliaris miliaris (Linnaeus, 1758)

Erythrolamprus miliaris orinus (Griffin, 1916)

Etymology

The subspecific name, merremi is in honor of German herpetologist Blasius Merrem.

Liophis milaris intermedius, a taxonomic error

In 1991, Erythrolamprus miliaris intermedius was described by Henle and Ehrl. However, they made a mistake. It was later discovered by Dixon and Tipton, through various comparisons of morphometrics, that Erythrolamprus miliaris intermedius was actually Erythrolamprus reginae.

Geographic range

Erythrolamprus miliaris is found in South America east of the Andes, from the Guyanas south to Paraguay. The former subspecies extending further south (southeastern Brazil, Paraguay, Uruguay and northeastern Argentina) is now recognized as a full species, Erythrolamprus semiaureus.

Habitat

Erythrolamprus miliaris inhabits aquatic and riparian habitats. It occurs in both lowland tropical rainforest and Atlantic forest at elevations below 100–700 m (330–2,300 ft).

Physical characteristics

Erythrolamprus miliaris is stout-bodied (muscular) and relatively short-tailed. Tail length/total length ratios vary from 15.0%–19.8% with an average of 18.6%.

Adults may attain a total length (tail included) of about 50 cm (about 20 in).

Dorsally, it is pale olive-brown or yellowish, with each smooth dorsal scale edged with black. Ventrally, it is uniformly yellow.

Feeding

Erythrolamprus miliaris feeds on a wide range of prey items. They include primarily amphibians (including eggs and tadpoles), but also fish and even lizards and small rodents. Invertebrates have also been reported but may have been secondarily ingested. However, there is little information on its feeding habits. A study indicated that females with oviductal eggs did not feed, whereas those females with secondary vitellogenic follicles fed more often than did the non-reproductive ones.

Sexual dimorphism