Conservation news

It’s in the genes: researchers use DNA to learn about tapir behavior

Tapirs are notoriously hard to find and directly observe in the wild. Because of this, little is known about how species behave in their natural habitats. But in a study published in PLOS ONE, researchers found a way around this complication by using tapir DNA to shed light on their behavior.



The team sequenced and compared the DNA of individual tapirs to determine how related they were to one another, and in so doing, determine how far they dispersed throughout their habitat. This study marked the first time this specific technique had been used in the Amazon region.


“I think that people who want to work with conservation should be open to use all kinds of tools, and interdisciplinary studies can bring very interesting results,” co-author Gabriela Pinho, from Brazil’s Instituto Nacional de Pesquisas da Amazônia (National Institute of Amazonian Research), told mongabay.com.




A lowland tapir (Tapirus terrestris) crosses a road in the Pantanal. This species is listed as Vulnerable by the IUCN. Photo by Rhett A. Butler.



Pinho used DNA obtained from lowland tapirs (Tapirus terrestris) in the Balbina Reservoir, created in 1987 by the Balbina Dam in the central Amazon. Tapirs have been little studied in the region; Pinho sought to help fill this gap by researching tapir social behavior via estimates of relatedness between individuals using non-invasive sampling of feces.



“I chose to work on non-invasive sampling of tapirs to uncover aspects of their social behavior for several reasons,” Pinho told mongabay.com. “First of all, the use of DNA extracted from feces to estimate relationship between individuals was never used in the Amazon, and, if…successful [for this study], it could be used for other species. Second, the tapirs are the biggest mammals in South America and there is an incredible lack of knowledge about their behavior and population dynamics.”



Tapirs, which are listed as Vulnerable by the IUCN, are difficult to study because they are both solitary and nocturnal. Much of the battle in traditional observational studies involves first locating a tapir, and then finding a way to observe the rare direct interactions between them. Indirect data collection, such as sampling feces, allows scientists to learn about tapirs without having to actually locate them.


Tapirs are large, herbivorous mammals native to Central and South America, and Southeast Asia. They are superficially similar to pigs, have a long prehensile snout, and are most closely related to horses and rhinoceroses.




A lowland tapir in Yasuni National Forest in Ecuador. Like horses and rhinoceroses, tapirs are classified as odd-toed ungulates. Photo by Jeremy Hance.



“Tapirs are quite unique,” Pinho said. “[They] look like a mixture between a pig, elephant, and a horse, with a small and very flexible snout, dark skin, short mane, horse-like ears, and almost no tail.”



Lowland tapirs can grow upwards of 400-660 pounds (180-300 kilograms). However, despite their size, they are quiet and shy.



“You can notice them just when they are very close and step with their big hooves in a root or whistle to communicate with other individuals,” Pinho said. “But, when encountered in the forest, they tend to dive (they are very good swimmers) or run away.” She added that the sound of a running tapir is “close to a mini tractor.”



The team used a basic DNA-isolation kit, called QIAAmp DNA Stool Mini Kit (QIAGEN). According to the company website, the kit takes just 50 minutes to get results. The team got its DNA samples from the tapir feces, which, according to Pinho, are “not easy to find in the dense forest.” The team overcame the painstaking process of looking for feces in the middle of the Amazon by using footprints on the margin of the islands as an indicator of the presence of tapirs and, therefore, tapir feces in the Balbina Reservoir. In total, the team found approximately 1,000 feces samples over the course of 55 days. For Pinho, “it was not an easy life!”



All samples were analyzed in the Laboratory of Evolution and Animal Genetics (LEGAL), at Federal University of Amazonas. The DNA is concentrated in the shed intestinal cells on the surface of dung. Because of the hot and humid Amazonian climate where the fecal samples were found, they degraded quickly. After only 15 days in the lab, the team observed that the DNA would decay to the point of uselessness. Of the 1,000 samples that the team found, only 32 could be used in the study. Multiple DNA extractions were needed for each sample. However, considering that tapirs are so hard to sample, the researchers considered this to be a good sample size.




A young lowland tapir. This species is also known as the Brazilian tapir and South American tapir. Photo by Rhett A. Butler.


The researchers found that all their samples came from just one expansive tapir population in the Balbina Reservoir region. This means that individuals ranged far and wide, even crossing a large dammed river, to mix with other groups.



“In this study, we generated novel information about lowland tapir social behavior,” Pinho said. “It’s basic information that can be used for tapir population management and, while there is no similar study for the other tapir species, it is a good approximation.”


Still, the study recommends caution when using its results to signify behavior patterns.



“This study was developed in an area impacted by a dam and we do not know if the tapirs’ natural behavior was disturbed by the flooding in the area or not,” Pinho said.



Pinho is collaborating with the Lowland Tapir Conservation Initiative ( LTCI-IPÊ, www.tapirconservation.org.br) and using genetics techniques to estimate the relatedness between already-monitored tapirs in environments undisturbed by human activity. By comparing the results of natural areas to those with dam development, they will be able to more effectively evaluate the impact of large human disturbance on the social behaviors of tapirs.







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