* About 400 lions thought to remain in West Africa
* Cat is leaner, less hairy than other African lions
* Conservation efforts weak compared to east Africa
By Emma Farge
DAKAR, Jan 14 (Reuters) - West Africa's lions, which once prowled across the region in their tens of thousands, are close to extinction as farmland eats up their ancient habitats and human hunters kill the animals they feed on, a study has shown.
Just around 400 of the animals were thought to have survived across 17 countries, according to the paper published in scientific journal PLOS ONE.
"These lions are standing on a cliff looking at the chasm of extinction," Luke Hunter, one of the paper's authors and president of wild cat conservation group Panthera, told Reuters on Tuesday.
"It would be very easy for small, isolated populations to be wiped out over the next 5-10 years."
Fewer than 250 of the survivors were mature cats, capable of breeding, the study said. But even that ability to produce cubs was limited by the fact they were spread across wide areas in groups that often did not have enough lionesses to sustain a population.
The study said there had been no comprehensive study of the size of past populations, though Hunter said there would at one stage have been "many tens of thousands" of lions.
The study, led by Panthera, said they were now only present in 1.1 percent of their original habitat and recommended they should be classified as "critically endangered".
Conservation efforts in a region known for its poverty and political instability, have been weak compared to other parts of Africa, and the population density is about 15 times lower compared with lions in east Africa, the study said.
Parks in the region typically had four staff or fewer per 100 square kilometres, it added.
One of the main reasons for the decline was the conversion of habitat into farm land. Others included sharp falls in the numbers of antelope, buffalo, and other prey, and villagers killing lions in revenge for the loss of livestock.
"It's become very complicated for this carnivore at the top of the food chain to find enough space and food to survive," said Hunter.
The West African lion, a relatively slender animal with a thin mane, is genetically distinct from the rest of the African species.
For a link to the study, click here: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0083500#s4 (Reporting by Emma Farge; Editing by Andrew Heavens)