A zoo in Mexico has been showing off an unusually large litter of Mexican grey wolves to the media.

Eight cubs of the endangered subspecies were born in Los Coyotes Zoo in Mexico City in April.

It is unusual for there to be more than four cubs in a litter so conservationists were delighted when mother Pearl gave birth to eight healthy cubs.

An official said that there were only 350 of the wolves left in the wild.

The Mexican grey wolf was almost wiped out by hunting, trapping and poisoning, but the US and Mexican authorities are trying to reintroduce them to the wild.

Conservationists said they hoped that the eight new additions could eventually be released.

They were born in a den in a wooded 3,700-sq-m enclosure which is out of bounds for visitors. In order to make conditions as natural as possible inside the den, no cameras were installed.

Keeper Felipe Flores said the first zoo staff knew of the birth was when Pearl emerged from the den skinnier than she had gone in.

The cubs themselves ventured from the den for the first time at three-and-a-half weeks of age.

Mr Flores described them as "playful and adventurous".