"As census in the Virunga Eco-system has not been possible for the last 14 years in both Rwanda and DRC due to insecurity, except the one held in Bwindi Impenetrable Forest last year, this one will determine their numbers in other areas," UWA official Lilly Ajaroza told AFP by telephone.

The Virunga eco-system consists of Mgahinga Game Park in Uganda, Virunga Park in the DRC and Volucano Park in Rwanda, where 324 individual gorrillas were found in 32 groups during the last census in 1989.

The census is supposed to be held after every five years.

UWA said that the exercise, being conducted by a 100-person team, started last month and will last until the end of October to determine the effects of wars on the population of the rare primates.

"The ongoing exercise will determine the effect of natural and man-made factors on the population of the gorillas, and help conservationists understand the long-term viability of such a small population of critically endangered animals," UWA said.

In Bwindi Impenetrable Park in southwest Uganda, figures of the past three censuses indicated an increase in the population from 257 in 1994 to 292 in 1997 and 315 during last year's census.

Bwindi was the scene of an attack in 1999 by suspected Rwandan rebels, who killed eight foreign tourists including Americans, Britons and New Zealanders.

Rwanda was rocked in 1994 by a genocide in which up to a million ethnic Tutsis and their Hutu supporters were killed, and DRC emerged from a five-year war in April this year.

The census exercise is funded by international conservation organisations including the Wildlife Conservation Society (WCS) and the International Gorilla Conservation Society (GCS).

TERRA.WIRE