In the forest during the day the noise from birds, monkeys, insects and other animals is deafening. In the middle of the night there is silence with a few noises of insects and frogs. And sometimes some night birds scream like owls in the dark.
Thanks to the song of owls, Brazilian researchers were able to discover four species in the Amazon and Atlantic forests, two of which were unprecedented for science.
Among the new owls that are now joining the diversity of Brazilian birds is the owl xingu Megascops stangiae, named after Sister Dorothy Stang, an American religious and activist in the Xingu region who defended the rights of farm workers. Dorothy Stang was murdered six times in an ambush in 2005 in the area of the PDS (Sustainable Development Project) in the Esperança settlement.
At that time, according to a witness report, a little more than a week after the crime, the police arrested two armed men who confessed and appointed the farmers Vitalmiro de Bastos de Moura (Bida) and Regivaldo Galvão (Taradão) as clients and Amair Feijoli da Cunha had (Tato) as an intermediary.
The discoveries of owls began during the doctoral thesis of the biologist Sidnei Dantas, which was developed at the Museu Paraense Emílio Goeldi in Belém (PA). When the researcher heard the singing of a screech owl (Megascops usta) in the Serra dos Carajás north of the Xingu National Park, he found the sound, who was already enthusiastic about the singing of these animals, strange, different than expected for this species.
He then had a chat with his supervisor, Alexandre Aleixo, former curator of the museum’s bird collection and currently a researcher at the University of Helsinki. Together they began an investigation of the occurrence and distribution of these and other species in the complex of the so-called tawny owl.
The Megascops genus is the most diverse owl in America with 21 known species spread from North America to South America. The Amazon complex has been divided into little owls (Megascops watsonii) north of the forest and little owls south. In the Atlantic forest region, the known species was the screech owl (Megascops atricapilla).
Because they are nocturnal birds, the colors of the owl plumage do not vary much, which makes it difficult to distinguish between species. “To find out how these species were distributed in Brazil, in addition to analyzing specimens in scientific collections and singing, we also conducted field collections to better understand the group’s relationships,” says Dantas.
The researchers collected data from more than 252 specimens in collections, 83 vertices and more DNA from 49 specimens, and came up with a family tree of the group with the occurrence of two previously unknown species: the owl of Xingu and the owl – of-alagoas. The latter received a new classification because it differs from that which lives downhill in the Atlantic forest of the state of Bahia.
In addition to the two new species, the demarcation of the range of occurrence of the screech owl and the screech owl (Megascops ater), which were previously considered a subspecies of the screech owl, was an important contribution of the study. “Traditionally, these Amazonian species were viewed as one species, with a distribution from Guyana west of the Negro River. However, our work has shown that where it was previously thought that there was one species and perhaps two subspecies, there are actually four different species, ”says the biologist.
The owl toad is relatively common in the Atlantic forest, from the state of Bahia to Paraná, but an isolated population in a forest fragment at the Serra Grande plant in the Ibateguara municipality revealed the Alagoas species. “Just like the owl from Xingu, we could only find the new species of owls from Alagoas using molecular analysis because the morphology data were very similar,” he says.
The distribution of the Alagoas owl extends a little further in the region, reaching the border with the state of Pernambuco. However, in these two areas there are only very small fragments of the Atlantic forest.
Now, the biologist says, the discovery, which included researchers from Drexel University in Philadelphia, the Federal University of Pará, and research from the Field Museum in Chicago, should steer conservation efforts: both the owl laguas and the owl of Xingu are already considered threatened with extinction.
“These populations are all very fragmented, they are no longer connected to one another due to the destruction of the forest. Unless there is a forest restoration project, these animals are unfortunately threatened with extinction. “
The two new Amazon species are endemic to Brazil and occur in forest areas that are exposed to severe impacts due to deforestation. “The owl from Xingu is located exactly in the so-called deforestation arc. It is for this reason that we have chosen to pay tribute to Sister Dorothy, who was an important figure in the area, to bring global attention to this part of the Amazon that is being destroyed at an alarming rate, ”he says.
Dantas’ research is one of many others to find out what is still hidden in the middle of the largest tropical forest in the world. It also raises an alarm for the existence of species that are not yet discovered and threatened with extinction in areas of the Atlantic Forest, the most severely degraded Brazilian biome in the past. Around 8% of the original coverage is still available.
With regard to the owl complex, it is possible that further studies of the complex will reveal even greater diversity. “We know the formation of the great rivers in the Amazon Basin was a pivotal event in the segregation of owl species, but we weren’t able to discover true diversity until more than 150 years after it was first discovered. If you look at the rest of the genus, you’re sure to find many more species, ”he concludes.