The arrival of new baby Golden Lion Tamarins on February 14th has brought particular joy to Zoo Basel. Castor (17) and Lilian (5) have become an experienced breeding pair with their second delivery of twins. Last year, they made the headlines with Basel Zoo’s first golden lion tamarin birth in twenty years. This year’s two baby Monkeys are full of energy and doing very well.
The zoo has had to wait a long time for these happy events, as the last opportunity to marvel at young golden lion tamarins in Basel was twenty years ago. The first pairing between Castor, from Sweden, and Lilian, imported from Holland, took place following an approach phase of just under two years in exile whilst the monkey house was being renovated. Apparently they now feel equally at home in the re-opened monkey house, demonstrated by the arrival of their two offspring on 14th February this year. Twin births are common in Tamarin and Marmoset pairings, and are standard for Golden Lion Tamarins.
Golden Lion Tamarins live in family groups of up to ten. In Brazil’s Atlantic rainforest, their area of origin, a family will claim a territory covering an area at least four times the size of Basel Zoo. What is particularly fascinating about these monkeys is the way in which social frameworks vary greatly from family to family. The most common framework is a pairing for life (monogamy), followed by a female with multiple male mates (polyandry) and a male with multiple female mates (polygyny). All members of the group are needed to successfully rear young. For example, the father offers energetic help in carrying the young monkeys around on his back.