Ecology – The return of the tapir to Rio

Tapirus terrestris means lowland tapir in German. But this largest land mammal in Latin America, which weighs up to 300 kilograms, is also native to mountainous regions such as the Atlantic Rainforest in Brazil. However, in the state of Rio de Janeiro, excessive hunting, deforestation and urban sprawl wiped out the tapir more than a century ago.

Now Tapirus terrestris has returned to the southeast Brazilian state. A mother and her young fell into a camera trap in the 38,000-hectare Cunhambebe National Protected Area in the south of Rio de Janeiro last year. This is the first record of a spontaneous return of tapirs since 1914, when they were last seen in the Rio Atlantic Forest.

According to biologist Marcelo Cupello of the State Environmental Institute (INEA-RJ) in charge of the protected area, footprints and tracks suggested that more than two tapirs may be roaming the Cunhambebe undergrowth again. Cupello believes they probably migrated from the Serra do Mar nature reserve in neighboring São Paulo state. There is still a relatively stable population of this species there. Scientists estimate the number of tapirs in the 360,000 hectare Serra do Mar reserve at 249 to 1,494 animals. However, genetic analyzes that could confirm the migration of the tapir family from São Paulo were still missing.

Since 2018, a group of around 20 tapirs have been living again in the Guapiaçu (Regua) bioreserve in Cachoeiras de Macacu north of the metropolis at Sugarloaf Mountain. But these animals are the result of the Refauna reintroduction project and not returnees. The presence of Tapirus terrestris in the Cunhambebe Nature Reserve is very important news for science, emphasizes refauna coordinator Maron Galliez. It shows the potential for expansion and adaptation of these large mammals even in fragmented Atlantic rainforest areas such as Cunhambebe.

Tapirs are considered the “gardeners” of the rainforest. Their absence leads to ecological imbalances and forest restructuring; they play an essential role in the spread of large tree species. Since they feed on the fruits of certain species, they spread the larger seeds in particular with their droppings, thereby promoting the natural regeneration of the forest. In addition, together with the umbilical pigs, they make a significant contribution to fertilizing the soil.

A study published in 2021 by the State University of São Paulo showed that in areas without these frugivores, levels of the nitrogen compound ammonium in the soil were up to 95 percent lower. The results demonstrate for the first time the importance of tapirs for the nitrogen cycle and, according to the researchers, are a further warning of ecosystem losses caused by the disappearance of large mammals from tropical forests.

The Atlantic Rainforest biome originally stretched contiguously in eastern South America for 4,000 kilometers from Argentina to northeast Brazil. Of these, only about eleven to 16 percent are left. A long-term study published in 2022 by an international team of researchers on the distribution and conservation status of Tapirus terrestris in the Atlantic Rainforest showed that there are still around 2,665 to 15,992 tapirs in at least 48 fragmented populations in the fragmented remaining areas of this biome.

“The results of this study give cause for cautious optimism about the future of tapirs in the Atlantic Rainforest,” is the conclusion of the study. Although nature reserves are severely underfunded, particularly in Brazil, tapir populations have begun to recover and are reoccupying areas where they have not been present for decades or longer. “Most of the biome’s tapir populations face no obvious immediate threat,” the researchers write. And in nine protected areas, the number of specimens of this species, which is important and unique to the forest ecosystem, appears to be increasing.

Tapirs are considered the “gardeners” of the rainforest.

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