Monkey Business at London Zoo!

London Zoo is celebrating the birth of twin Geoffroy's marmosets, the first to be born in the Zoo for 32 years. The babies, as yet unsexed, were born on 30 August 2002. The twins are the latest in a notable run of marmoset births at London Zoo, success stories have included; Goeldi's monkeys, golden headed lion tamarins and pygmy marmosets.

The new arrivals are blackish-brown in colour, their faces are ringed by white fur and, like most other marmosets, they have tufted ears. The babies are currently about 25 centimetres from their nose to the tip of their ringed tail.

Geoffroy's marmosets are rare due to the destruction of their habitat through deforestation and can only be found in the coastal rainforests of Eastern Brazil.

As is typical with Geoffroy's marmosets, the twins are being looked after mainly by their father, who carries them on his back until feeding time, when he delivers the babies to their mother to be suckled. The youngsters will feed from their mother until they are about seven months old, when they will begin to eat their normal adult diet of fruit, insects and tree gum. In the wild Geoffroy's marmosets use their sharp canines to gouge holes into trees from which the gum is obtained. In captivity Geoffroy's marmosets are provided with similar stimulation by tree gum rubbed onto the branches they have gnawed.

London Zoo currently cares for six Geoffroy's marmosets, although the species can live in family groups of up to ten animals, consisting of the dominant pair and their offspring. Geoffroy's marmosets do not become sexually active until after they have left the family group, as the parents produce a hormone that suppresses the sexual development of the offspring to avoid in-breeding.

Geoffroy's marmosets are completely monogamous, and when breeding they usually give birth to twins after a four and a half month gestation period.

These primates are most active in the daytime (diurnal) and can be seen climbing branches and foraging for food in their enclosure.

Frank Wheeler, Head Keeper of the Small Mammal House at London Zoo, said, "The arrival of the baby Geoffroy's marmosets is fantastic news for all of us here at London Zoo, and also for the species in general. We haven't had a breeding pair at the Zoo for over thirty years, so this is a particularly exciting arrival! We look forward to breeding more Geoffroy's marmosets and adding to our collection in the future."

Notes to editors:

• Geoffroy's marmosets typically have twins

• At birth the young weigh approximately 40g and measure approximately five to six centimetres in body length

• Female Geoffroy's marmosets breed from about 18 months to 18 years of age. The mother of London Zoo's new twins is three years old, and came to London Zoo from Belfast Zoo in March 2002. The father is eight years old and came to London Zoo in April 1996 from Banham Zoo. The twins are the first offspring produced by this couple

• Founded in 1826, the Zoological Society of London (ZSL) is an international scientific, conservation and educational charity: our key role is the conservation of animals and their habitats. ZSL runs London Zoo and Whipsnade Wild Animal Park, carries out scientific research in the Institute of Zoology and is actively involved in field conservation in other countries worldwide

Contact: Nathalie Golden
Tel: 020 7449 6280
E-mail: nathalie.golden@zsl.org