Nigeria, Oct. 12 -- A Nigerian conservation scientist, Edem Eniang, says he has not encountered some snake species that were once commonly seen in several parts of the country during more than two decades of fieldwork, raising concerns about the state of Nigeria's poorly monitored snake populations.

Mr Eniang, a professor and executive director of the Biodiversity Preservation Center, Uyo, Akwa Ibom State, said habitat destruction, deforestation, indiscriminate killings and illegal wildlife trade were among the pressures threatening snakes, although the absence of long-term, species-specific data makes it difficult to establish the scale of their decline nationally.

"In the last two decades of my field, we have not come across some of o...