Wrens of Ecuador – Group Sing
Music; Ambience: Plain-Tailed Wren song
JM: Wrens are small, pugnacious birds. A pair of them will typically defend their nesting and feeding grounds from intruders, by sonorously marking their territory with a well-coordinated duet. So why then would a group of these birds sing and live together as a kind of extended family? I’m Jim Metzner, and this is the Pulse of the Planet. On a recent trip to Ecuador, Biologist Nigel Mann made an unusual discovery unlike other wrens, who duet and live in pairs, Plain-Tailed Wrens apparently sing and interact as a chorus.
NM: “They weren’t singing as pairs and they were interacting and behaving as groups. They were foraging together. They would stick together as a group. Essentially these were cohesive units. At this stage we don’t know who the constituent members are in these particular groups. We don’t know the relatedness. We anticipate that these groups consist of a breeding pair, that are the dominant male and the dominant female. And the other individuals around them are their offspring more than likely, from previous breeding attempts. So, you have a breeding pair plus helpers.”
JM: Other species of birds have helpers, but this had never been seen before in wrens. Nigel Mann thinks that perhaps it was a lack of available territory that led to the Plain-Tailed Wren’s unusual behavior.
NM: “These bamboo forests are fragmented, but within them the territories seem to be full of Plain-Tailed Wrens. It may be that they have to wait their time before they can, gain their own territory. Almost as a payment if you like for staying on the parents territory, perhaps they then have to pay for the keep, if you like, if you want to put it into those terms, by helping defend the territory from other individuals. So they join in the singing.”
JM: This group of wrens weaves together this song in a remarkable way. We’ll hear about that in future programs. Pulse of the Planet is made possible by the National Science Foundation. I’m Jim Metzner.