Tamarins, small monkeys that have a high tolerance to human disturbance of their habitat, may help tropical forests recover from deforestation, according to a study in Scientific Reports. Tamarins feed on fruit and may drop seeds from adjacent forests in deforested areas, enabling the growth of new plants and trees.
Eckhard Heymann and colleagues used long-term ranging and feeding data on two tamarin populations of the species Saguinus mystax and Leontocebus nigrifrons, which they observed in an area in the Peruvian Amazon that was logged in 1990 and used as buffalo pasture until 2000. The authors showed that, after humans had abandoned the area, tamarins from the nearby forest increased their use of it over time. The monkeys exploited a total of 31 plant species for fruit, with one fruit species used for food in 2000, six in 2005, 12 in 2006, 16 in 2007 and 19 in 2008.
The authors also followed the development of 487 plant seeds for one year. They found that 47 (9.6%) of these seeds were dispersed by the tamarins from the forest into the abandoned pasture. Of these, 15 seeds (31.9%) survived for at least one year and germinated. In comparison, 82 out of 440 (18.6%) seeds dispersed in the forest survived for at least one year.These differences might be due to a higher availability of light in the pasture, lower competition or predation pressure, or a combination of these factors. As tamarins were the exclusive seed dispersers of the plant Parkia panurensis ―a major food resource for primates ― at the study site, the authors also analysed the genes of 37 P. panurensis seedlings. They matched more than half (19) of these seedlings to 11 parent trees in the nearby forest, confirming the effectiveness of seed dispersal by tamarins.
The findings suggest that although regenerating forests may not fulfil all ecological needs of tamarins, which continued to depend on the original forest throughout the study period, tamarins can contribute to the natural regeneration of forests that have been disturbed by human activity.