Teaching wild birds to sing a new tune

Date:  October 4, 2018

Source:  Cell Press

Like toddlers learning to speak, young birds learn to sing by listening to the voices of adults. Now, researchers reporting in Current Biology on October 4 have shown for the first time that they could teach young sparrows in the wild how to sing a new tune. The wild birds then passed the new songs on to the next generation.

"I was quite shocked that our loudspeakers succeeded in teaching wild birds to sing," says Dan Mennill from the University of Windsor in Ontario, Canada. "The sparrows in our island-living population had abundant opportunities to learn songs from live tutors, and yet thirty birds learned songs from the loudspeakers, providing experimental evidence of vocal learning."

Conventional experiments of vocal learning in birds have been conducted in the laboratory. But such studies are much more difficult to do in the wild. The researchers overcame the challenges in the new study by focusing their attention on Savannah Sparrows living at Bowdoin Scientific Station on Kent Island. The sparrows on this island often return to the place of their birth to breed as adults. That made it possible for researchers to expose young birds to novel songs and then record those same animals when they returned from migration to breed the next year.

Mennill's team, including researchers from the University of Windsor, University of Guelph, and Williams College, developed a new type of loudspeaker that is programmable, solar powered, light activated, and weatherproof. The speakers allowed them to broadcast adult songs with distinctive acoustic signatures for the wild sparrows over tutoring sessions that lasted for months. Over a six-year period between 2013 and 2018, they experimentally tutored five cohorts of Savannah Sparrows, from the time they hatched to adulthood.

Across the five cohorts, thirty birds produced songs that matched the broadcasted songs. Those songs differed from anything the birds would have heard otherwise. In all thirty cases, the researchers report, the birds produced songs containing phrases that had never been recorded on the island in three decades of field study.

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Lasting severe weather impact found in feathers of young birds

Date:

March 3, 2015

Source:

University of Oklahoma

Summary:

While studying a ground-nesting bird population near El Reno, Okla., a research team found that stress during a severe weather outbreak of May 31, 2013, had manifested itself into malformations in the growing feathers of the young birds. The team witnessed a phenomenon termed 'pallid bands' in a large proportion of fledgling Grasshopper Sparrows and found spikes in the chemical signatures of 'pallid bands,' which led to abnormalities in the new feathers.

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Young birds can get 'drunk' on fermented berries

But unsteadiness on the feet, a tendency to fall over, and losing the ability to steer is considerably more of a problem when life is normally spent in trees or in the air.

The authors from the Animal Health and Veterinary Laboratories Agency (AHVLA) reveal how they were called to a primary school in Cumbria last summer after the bodies of 12 young blackbirds were found.

A further blackbird was discovered alive, but obviously "unwell." And two more dead birds were subsequently found.

Foul play was suspected, especially as some of the birds had clearly been injured. The police were called.

Post mortem exams were carried out on the dead birds, who were otherwise in good physical condition. Tests to rule out lethal infections, such as avian flu, came back negative. But berries were found in all the birds' guts.

A few blackbirds had been spotted on rowan trees, beneath which berries similar to those found inside the dead birds covered the ground. Many of these berries looked as if they had been partially eaten.

Rowan berries are not normally considered poisonous to wild birds, but the berries found inside the birds smelled as if they were fermenting.

Three tissue samples from the dead birds were sent for toxicological analysis, one of which revealed high levels of pure alcohol (ethanol). Staff at the wildlife rescue centre to which the live bird was sent also reported that it had been unsteady on its feet and appeared "drunk."

The bird had had to place its wings on the ground to steady itself, and had leant against the walls of its enclosure to keep upright, they said. After two days the bird fully recovered and was released back into the wild.

The authors can't explain why only one of the samples revealed the presence of ethanol, but suspect that all the dead birds had become intoxicated on fermented berries, and that some of the injuries they had sustained were the result of mid-air collisions.

Continued:  http://www.sciencecodex.com/young_birds_can_get_drunk_on_fermented_berries-101400