Slet’s welcome the return of sunny days with this mini-miracle repeated a thousand times: nesting and its fascinating parade of aerial ballets. Let’s take some tits, the most famous winged companions in our gardens. Where we see these birds take turns darting, flying, spinning, landing on the ground, pecking, flying away, changing their wings, running about and busy… whose beaks are loaded with twigs, to build the nest, which is a beak has been weighed down with caterpillars to feed the young.
In this incessant whirl, the partners ruthlessly take turns… with the risk of collision. It happens that between M. and Mme Mésange, the accident was barely avoided – the author of these lines witnessed it one day.
A lack of communication within the couple? This is suggested by the discovery of a new body language in the Chinese tit (Parus minor), a cousin of our great tit (Parus major), smaller and the abdomen paler.
As the name doesn’t indicate, this songbird also lives in Japan, where researchers from the University of Tokyo monitored the behavior of eight pairs breeding in nest boxes. This team therefore examined 321 nest visits. When the birds arrived at their roost to feed their offspring, they would often land on a nearby perch where they waited. And they always entered their shelter one by one.
But the researchers noticed a strange attitude: When one of the two parents waited like this, it often flapped its wings in the other’s direction. Even better, “it only flapped its wings in the presence of its partner, who was almost always the first to enter the nest box”summarizes Toshitaka Suzuki, co-author of this work, which was published in the journal on March 25 Current biology. Behavior that stopped after the partner entered the home.
“A symbolic gesture”
Strikingly, females flapped their wings much more often than males: six of the eight females studied showed this behavior, compared to only one of the eight males (and none of the partners of the eighth pair). A difference related to gender of which “ecological significance remains intriguing”, the authors say cautiously. Once this gesture was performed by a female, the male usually entered the nest box, regardless of which mate arrived first. If the female wasn’t flapping her wings, she usually went in before the male.
According to the authors, this subtle flapping is not a simple gesture “ deictic”, that is, intended to indicate an object of interest. “It is a symbolic gesture that conveys a specific message”, they write. An elegant way to invite your partner to enter the nest box, without any physical contact. An “after you, dearest”, in short.