Golden lion tamarins inhabit the Atlantic coastal rainforest of Brazil in the areas just north of the city of Rio de Janeiro. Only about six percent of this rainforest remains. Estimates of the numbers of animals in the wild have varied over the years, and it has only been relatively recently (since 1990) that estimates have been made for the full extent their historical range.
There are 650 GLTs in the reintroduction population, including several generations of GLTs that have been reintroduced. As of May 2006, the wild populations of GLTs include:
All together, there are about 1,500 golden lion tamarins living in the wild.
In addition to these, there are about 450 golden lion tamarins in 150 zoos around the world.
Predation at Poço das
Antas Biological Reserve
Until 1997, all suitable habitat in Poço das Antas Reserve was occupied by about 347 golden lion tamarins. Mean group size was 5.6, infant survival was very high and most mortality occurred during dispersal by natal individuals two to three years of age. Turnover of breeding individuals was infrequent. Predators occasionally took individual tamarins or pairs, but the first loss of a study group to predators occurred in 1995.
One group was lost in 1996, two in 1997, three in 1998, four in 1999 and five in 2000. In summary, predators extirpated all but one of the 15 groups under study by project scientists in the past three years. Typically, these events involved predation of several tamarins simultaneously, including one or both reproductive individuals in the group. In most cases new reproductive groups soon colonized these territories, sometimes including survivors from the former group. Some territories have been recolonized as many as three times. We are not certain which kind of animal was doing the predation, but believe that it was a tayra (Eira barbara), a weasle-like predator fully capable of doing this kind of damage.
For the first time in 17 years,
areas with appropriate habitat in the reserve do not contain
tamarin groups. Numbers of tamarins in Poço das Antas
are now estimated at about 220, a 36-percent drop in overall population
size. Scientists from the University of Maryland are studying
the effects of these predation events on the viability of
the GLT population. Luckily, there were no predation events
in 2001 and the population is beginning to recover.