The findings also have important conservation implications for the cats, researchers said. Scientists had thought that there was a single species of housecat-sized Brazilian tigrina. (Agencies)
However, the molecular data now show that tigrina populations in northeastern versus southern Brazil are completely separate, with no evidence of interbreeding between them. As such, they are best described as two distinct species.
"Our study highlights the need for urgent attention focused on the Brazilian northeastern tigrinas, which are virtually unknown with respect to most aspects of their biology," said Eduardo Eizirik of Pontificia Universidade Catolica do Rio Grande do Sul in Brazil.
The new study further revealed a complicated set of relationships between the tigrinas and two other species of Neotropical cats.
That evolutionary history includes ancient hybridization and movement of genes between the pampas cat and the northeastern tigrinas (Leopardus tigrinus).
In contrast, southern tigrinas (newly recognised as Leopardus guttulus) continue to hybridise with Geoffroy's cats, leading to extreme levels of interbreeding between the species along their contact zone.
Those patterns add to evidence that hybridisation can and does occur between distinct animal species.
As for the two tigrina species, the researchers suggest that they may be suited to different habitats, with the northeastern cats living primarily in savannahs, as well as dry shrub lands and forests, and the southern species living in denser and wetter Atlantic forests.
"Such distinct habitat associations provide a hint to potentially adaptive differences between these newly recognised species and may have been involved in their initial evolutionary divergence," researcher Tatiane Trigo said.
"All four species are threatened, and we need to understand as much as possible regarding their genetics, ecology, and evolution to be able to design adequate conservation strategies on their behalf," Eizirik added.
The findings also have important conservation implications for the cats, researchers said.
Scientists had thought that there was a single species of housecat-sized Brazilian tigrina.