Squirrels listen in to birds' conversations as signal of safety

Hearing casual chatter of birds after predator call reassures squirrels to come off high alert

Date: September 4, 2019

Source: PLOS

Grey squirrels eavesdrop on the chatter between nearby songbirds as a sign of safety. Birds chatter when they feel safe to communicate the absence of danger or share their location. This "chatter" from multiple bird species could therefore be a useful cue to other creatures that there is no imminent threat.

To test this hypothesis, the researchers observed the behavior of 54 wild Eastern gray squirrels (Sciurus carolinensis) in public parks and residential areas in Ohio in response to threat, which they simulated by playing back a recording of the call of a red-tailed hawk (Buteo jamaicensis), a common predator of both squirrels and small birds. They followed the predator's call with a playback of either multi-species songbird bird chatter or ambient sounds lacking bird calls and monitored the behavior of each squirrel for 3 minutes.

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Related birds evolve different songs and colours

Canadian Researchers have discovered a pattern in birds' songs and plumage that help explain some of the colourful and tuneful variety in nature.

The team found that closely related birds that share the same habitat tend to look and sound different.

This evolutionary rule of thumb seems to help birds to identify members of their own species.

Dr Paul Martin presented the findings at the First Joint Congress for Evolutionary Biology in Ottawa.

He and his team studied 250 bird species throughout the world. With the help of the Macaulay Library of birdsong, they were able to compile a database of where the birds lived and what they looked and sounded like.

"We found, repeatedly, that birds that [live in the same location] with a close relative have more divergent songs and colour patterns," he told BBC Nature.

Continued:  http://www.bbc.co.uk/nature/18766653

A Bird's Song May Teach Us About Human Speech Disorders

ScienceDaily (Mar. 7, 2012) — Can the song of a small bird provide valuable insights into human stuttering and speech-related disorders and conditions, including autism and stroke? New research by UCLA life scientists and colleagues provides reason for optimism.


The scientists discovered that some 2,000 genes in a region of the male zebra finch's brain known as "Area X" are significantly linked to singing. More than 1,500 genes in this region, a critical part of the bird's song circuitry, are being reported for the first time. Previously, a group of scientists including the UCLA team had identified some 400 genes in Area X. All the genes' levels of expression change when the bird sings.

"We did not know before that all of these genes are regulated by singing," said Stephanie White, a UCLA associate professor of integrative biology and physiology and senior author of the new study. She believes the 2,000 genes -- at least some of which she believes are also shared by humans -- are likely important for human speech.

The research is published in the online edition of the journal Neuron, a leading neuroscience journal, and will appear in an upcoming print edition.


Read more:  http://www.sciencedaily.com/releases/2012/03/120307094653.htm

Bird song-sharing like verbal sparring

While singing the same songs as your neighbours may sound harmonious, research conducted at Queen’s University Biological Station (QUBS) suggests that song-sharing amongst song sparrow populations is actually an aggressive behavior, akin to flinging insults back and forth.


“It’s been hypothesized that repertoire size and song complexity is about the singer’s ability to advertise their quality as a mate,” says lead author Janet Lapierre, a visiting biologist from the University of Western Ontario (UWO). “Song-sharing, where birds sing a smaller number of their species’ greatest hits, is a more aggressive and attention-seeking behaviour. It’s also a behaviour most often displayed by belligerent older males.”

Ms Lapierre and fellow QUBS researchers Daniel Mennill (University of Windsor) and Beth MacDougall-Shackleton (UWO) used a 16-channel acoustic location system to investigate whether male song sparrows preferentially choose to sing highly shared song types or whether they use all song types interchangeably. They found no general tendency amongst the sparrows to either preference.

Instead, they found that the performance of highly shared songs is determined more by individual differences like age and the kind of neighbourhood the sparrows live in. ‘Tougher’ neighbourhoods had a higher percentage of sparrows who engaged in more aggressive song-sharing bouts, whereas ‘mild-mannered’ neighbourhoods tended to support more conflict-averse sparrows that avoid using shared song types.

Older male sparrows were the most likely to engage in more aggressive or attention-seeking song-sharing bouts, suggesting that older males may be more willing or able to risk conflict and may also have more experience in which songs are effective signals in their local area.

“The novelty of this study was that we looked at how birds use songs rather than just examining the content of their repertoires,” says Dr. MacDougall-Shackleton, a biology professor from the University of Western Ontario and a regular QUBS researcher. “We really could not have done this research without the longstanding study population of song sparrows at the Queen’s University Biological Station.”

These findings were recently published in Behavioural Ecology and Sociobiology.

http://www.queensu.ca/news/articles/bird-song-sharing-verbal-sparring