Ornithologists from the United States, Brazil and Finland have described two new species of the owl genus Megascops from the Amazon and Atlantic forests.
The Alagoas screech owl (Megascops alagoensis) in Brazil. Image credit: Gustavo Malacco.
Megascops is the most species-rich owl genus in the Americas, with 21 species currently recognized.
The genus comprises small- to medium-sized owls — commonly known as screech owls for their piercing calls — inhabiting a wide variety of habitats.
It reaches maximum species diversity in mountainous areas, such as the Andes and Central American highlands.
“Screech owls are considered a well-understood group compared to some other types of organisms in these areas,” said Dr. John Bates, curator of birds at the Field Museum in Chicago.
“But when you start listening to them and comparing them across geography, it turns out that there are things that people hadn’t appreciated. That’s why these new species are being described.”
“Not even professional ornithologists who have worked on owls for their entire lives would agree about the actual number of species found in this group, so a study like ours has been awaited for a really long time,” added Dr. Alex Aleixo, curator of birds at the Finnish Museum of Natural History at the University of Helsinki.
Previous studies have suggested that the tawny-bellied screech owl (Megascops watsonii), which is widespread in lowland Amazonia, might include more than one species.
They’ve also suggested that the black-capped screech owl (Megascops atricapilla), which is endemic to the Atlantic Forest, is closely related to the tawny-bellied screech owl complex.
“They’re cute little owls, probably 13-15 cm (5-6 inches) long, with tufts of feathers on their heads,” Dr. Bates said.
“Some are brown, some are gray, and some are in between.”
The Xingu screech owl (Megascops stangiae) in Brazil. Imager credit: Kleiton Silva.
In the study, the ornithologists compared the screech owls from the Amazon and Atlantic forests and found that there were variations in the sounds they made, indicative of different species.
They also examined the birds’ physical appearances and took tissue samples so they could study the owls’ DNA in the lab.
Altogether, 252 specimens, 83 tape-recordings, and 49 genetic samples from across the range of the tawny-bellied screech owl complex in South America were analyzed.
The combination of genetic variation, physical differences, and unique vocalizations led the researchers to describe two new species: the Xingu screech owl (Megascops stangiae) and the Alagoas screech owl (Megascops alagoensis).
While these two species are new to science, they’re already in danger of disappearing forever.
“Both new species are threatened by deforestation,” said Dr. Jason Weckstein, associate curator of Ornithology in the Academy of Natural Sciences of Drexel University and a researcher in the Department of Biodiversity, Earth, and Environmental Science at Drexel University.
“The Xingu screech owl is endemic to the most severely burned area of the Amazon by the unprecedented 2019 fires, and the Alagoas screech owl should be regarded as critically endangered given the extensive forest fragmentation in the very small area where it occurs.”
The two new species of screech owls are described in a paper in the journal Zootaxa.
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Sidnei M. Dantas et al. 2021. Multi-character taxonomic review, systematics, and biogeography of the Black-capped/Tawny-bellied Screech Owl (Megascops atricapilla–M. watsonii) complex (Aves: Strigidae). Zootaxa 4949 (3); doi: 10.11646/zootaxa.4949.3.1
