song

Adult Birds Use "Baby Talk"--and Babies Pay Attention

New research shows not only that baby birds learn songs best if they're tutored, but that adult birds seem to modify their songs the way we humans use baby talk. Further, activity in the babies' brains may have implications for research in attention issues in people. 

Birds do not hatch knowing how to sing. Like humans, they need to learn how to vocalize in socially meaningful ways. While it is known that baby birds learn from adults, Jon Sakata and his team of biologists at McGill University wanted to find out whether an adult needs to be present for the best learning or whether simply hearing the song is enough for baby birds. In other words, they wanted to find out whether the social connection matter when it comes to teaching.

For this study, male Zebra Finch chicks were observed learning songs from adult males either in person or by recording. (Why Zebra Finches? Because they breed well in the lab. And why just males? Because the males are the primary singers of the species.) The chicks, who had been cared for only by females prior to the study, were exposed for varying amounts of time to males singing in two different conditions. One group of chicks were tutored by a male in person; the other heard him singing to chicks in another room. The results? The chicks tutored in person learned their song more accurately no matter how long they were exposed to it. Further, the chicks who paid the most attention learned the best.

But the chicks weren't the only ones paying more attention. The males doing the tutoring took extra care when singing to their pupils. They repeated the beginning of the song, slowed down their phrases, and cleaned up some stray sounds. If you've ever spoken to a young child, you know exactly what these adults did. Further research is needed before anyone knows whether the adult males made these changes deliberately.

One last item of interest: the brains of the chicks who learned in person showed activity in two regions that showed no activity in the chicks who learned by recording. That is, the social activity of being taught in person seemed to activate mechanisms for attention. The research continues in order to identify just what those mechanisms might be.

What to know more? Read the abstract of the original study in the Proceedings of the National Academy of Sciences. The Washington Post has a nice article, too, complete with sound samples.

Female Songbirds: Quiet for Good Reason

Female birds are capable of song in 71% of songbird species, So how come we don't hear them as often as we hear the males? New research indicates that sometimes female songbirds have good reasons to stay quiet. 

Sonia Kleindorfer, a behavioral ecologist at Flinders University in Adelaide, Australia, studied the singing patterns of female and male Superb Fairywrens (Malarus cyaneus), a small Australian songbird species. Like the females of many species, female Superb Fairywrens often sing for territorial defense, sometimes even when they're on their nests. They use a melody known as a "chatter song." The male uses it too, but he is not as often near the nest when he sings.  This is a key difference, since singing alerts predators such as rodents, cats, and foxes. Kleindorfer investigated whether male singing or female singing poses a greater risk.

During the nesting seasons of 2013 and 2014, Kleindorfer and her colleagues monitored male and female singing on and near 72 wild Superb Fairywren nests, as well as the eggs and chicks in the nests. The scientists counted a nest as “attacked” if eggs or chicks vanished in under 25 days. In other words, if eggs disappeared unhatched or chicks disappeared before they were capable of fledging, researchers assumed they'd been eaten. 

Kleindorfer's team leaned that both males and females sang the chatter song more often when they were just beginning to nest. They sang it less often when they had eggs and chicks in the nest, and with one major gender difference: The males sang away from the nest and the females near or inside it. In fact, some females never sang at all, and some sang only in response to their noisy mates. To put it differently, the females sang less when doing so would endanger their nests. Proof? The scientists baited artificial nests with quail eggs and broadcast female chatter songs infrequently (six calls per hour) and frequently (20 calls per hour). Predators ate the eggs at 40% of the "frequent" nests, but at only 20% of the "infrequent" nests: the quieter nests were safer for the kids. 

Jordan Price, a behavioral ecologist at St. Mary’s College of Maryland, posits that danger to the nest could be the reason that female songbirds of other species sing far less than their partners—or not at all—when they're the primary on-nest parents. It's even possible that, generally, male songbirds sing not to attract mates but simply because there's no reason for them not to. The females, on the other hand, have to be more wary.