Wrens' calls reveal subtle differences between subspecies

Date:December 27, 2017

Source:American Ornithological Society Publications Office

Summary:Birds' songs and the ways they vary between places have been well studied -- but what can the simpler vocalizations known as calls tell us about bird biology? A new study provides the first detailed description of how Marsh Wren calls vary across eastern North America and hints at the evolutionary processes playing out between wren subspecies.

Continued

Good news for most Scottish bird species as numbers increase

The recent harsh winters in 2009 and 2010 may have also had an effect on some of our resident birds such as wrens and robins.

Index of abundance for Scottish terrestrial breeding birds, 1994 to 2011

March 2013. Scottish Natural Heritage (SNH) has released the latest figures tracking the abundance of Scotland's terrestrial breeding birds.

Farmland and woodland birds up, upland birds down
Over the long term, the abundance of terrestrial breeding birds increased by 11% from 1994 to 2011. Farmland and woodland birds have increased (by 12% and 44% respectively) and upland birds have decreased by 11%.

2010 - 2011 mixed results
Between 2010 and 2011, the main findings show that the abundance of all-species, woodland, and farmland terrestrial breeding birds were unchanged overall. However, the upland bird index decreased by 8%. The reasons for changes are not known for certain. Some evidence points towards land use changes as a possible cause. The recent harsh winters in 2009 and 2010 may have also had an effect on some of our resident birds such as wrens and robins.

Read the full report here 

http://www.wildlifeextra.com/go/news/scottish-birds013.html

Baby wrens must chirp a secret password to be fed, study finds

The nestlings of fairy-wrens don’t have much of a choice when it comes to listening to their mothers: The birds must reproduce a particular sound learned from their moms to be fed, according to a study published Thursday in the journal Current Biology.

The researchers, led by Sonia Kleindorfer of Flinders University in Australia, call the sound the bird’s “learned password.”

The team discovered the remarkable mother-chick ritual by chance when they noticed that the mothers were aiming calls at their eggs well before they hatched. So they set out to determine why. First, the researchers realized that the call made by the nestlings in order to be fed was different in each nest, suggesting it might be learned.

The pieces began to come together when the team also observed that each nest’s begging call — the password the nestlings need — was contained within the call that the mothers made to their unhatched eggs. In order to prove that the chicks were learning the sound from their moms rather than the song being innate, Kleindorfer and her team swapped the eggs from two different nests. Once hatched, the chicks produced the begging call of their foster moms, not their birth moms, proof the call was in fact learned in the egg.

Continued:  http://www.latimes.com/news/science/sciencenow/la-sci-sn-baby-wrens-must-chirp-secret-password-to-be-fed-20121108,0,4228548.story?track=rss