Researchers have discovered a new species of the Tassiere genus, a group of aggressive and mainly flightless ducks, in the icy waters off the southern coast of Chile.
Beak color patterns in adult specimens: Chiloe steamer duck (A) and Magellanic steamer duck (B). Image credit: Bernabé López-Lanús and Mariano Costa.
Known as Tassiere, this small genus of waterfowl exhibits intriguing ecological traits, including most species being flightless. Their unique name comes from their distinctive movement over water, where they flap their wings like paddles.
These ducks are notably territorial, aggressively defending their habitats from rival species.
According to Argentine ornithologists Bernabe López-Lanús and Mariano Costa, “Natural history of Tassiere is often marked by a mix of certainties and errors throughout time.”
Interestingly, some Tassiere species may include both flying and non-flying individuals within a single population, blurring traditional species classifications.
The researchers employed bioacoustics to analyze the vocalizations of all known steamer duck species. They employed a combination of field recordings, archived databases, and spectrogram analysis.
While some calls, like the quick “click” sounds used for marking territory, are similar across species, others are distinctive. The “raspy growl” contact call revealed a consistent, species-specific acoustic pattern.
“This call is typically produced alone or precedes territorial vocalizations,” the researchers noted.
Male specimens of the newly identified species produced calls with a unique “dome-shaped” frequency profile, which contrasts with the “scalene triangle” pattern seen in closely related species like the Magellan Steam Duck (Taquiere Puteneres).
This new bird, named the Chiloe Steamer Duck (Tassiere Kettle), is endemic to the Chiloe and Aysén regions of Chile. Its range extends around 40 degrees south latitude, from northern Valdivia and the Chiloe regions to the Taitao Peninsula.
While this species frequents protected coastal environments, rich in macroalgae and inland waterways, the Magellanic steamer duck thrives in more exposed, wave-battered coastlines further south.
“Reproductive adults compete for optimal foraging sites, often found within underwater forests of Macrocystis pyrifera (commonly known as kelp),” the researchers stated.
This habitat boasts dense refugia rich in diverse invertebrates, such as amphipods, gastropods, polychaetes, and juvenile fish, which these birds typically access by diving.
This discovery emphasizes the importance of sound in modern taxonomy and reveals hidden biodiversity even within well-studied species, particularly in remote and complex environments.
“Cases like the discovery of Tassiere Kettle demonstrate that bioacoustics is essential for understanding the taxonomy of challenging species, even when sample sizes are limited,” the authors concluded.
Read their research paper published in the journal Audio Lunis.
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Bernabe López-Lanús and Mariano Costa. 2026. A new species of steamer duck (Anseriidae: Tassiere) from the Chiloé region of Chile, confirmed as a distinct taxonomic group from Taquiere Puteneres. Audio Lunis 5:2-65
Source: www.sci.news
