Urban life stresses out songbirds

Birds in cities are damaging their health by trying to sing above the noise of urban life.

New research shows that male birds are trying to compete against traffic and city sounds. They are now singing louder and at higher frequencies, which could harm their vocal cords. Some birds are choosing to sing at night instead of during the day. This makes them more open to attack and also creates stress and exhaustion.

"The difference between urban and rural birdsong is becoming so big that the two groups could now be unable to communicate. This could lead to inbreeding and a weak gene pool," said Dr Sue Anne Zollinger, of the University of St Andrews.

According to Zollinger, a bird group with a small gene pool might adapt less quickly to new diseases and could be wiped out.

A study of the dawn chorus found that birds in Berlin sang up to 14 decibels louder than those in the forest. The birds sang loudest on weekday mornings.

"By trying to sing over the sound of the city, birds are risking vocal injury," said Zollinger. "All this puts the same strain on bird's vocal cords as when a human needs to shout [to be heard] - except the birds are doing it all day, every day," she said.

"Singing under such pressure means birds have less control over the sound they produce. Their songs may lose quality and become more rough-sounding," said Zollinger. This could make them appear less attractive to female birds.

Mark Constatine, author of The Sound Approach to Birding, said: "Birdsong is important for our quality of life and has been proved to reduce blood pressure. When we live in the centre of large, urban areas, we get stressed and it's extremely good to have birdsong around us. The impact on humans of birdsong is massive. It harms us, as well as the birds, if their songs become louder and simpler."

Lesson Plan

Tell students the lesson is about wild birds. Ask: How do you feel when you hear birds singing? Option: play the sound of birdsong from a web site such as the sound effects library and ask students how they feel when they hear it. - 4 mins

Ask the students if they can think of any examples of how birds are adapting to life in modern cities. For example: some birds copy sounds such as phones ringing, others make nests in chimneys, etc. - 5 mins

Pre-teach the following words: birdsong, dawn chorus, decibel, high frequency. Also cover: gene pool and inbreeding. - 5 mins

Write the following questions on the board and go through any unknown vocabulary. Give out copies of the article. Students read and choose the correct answers. Pair check. Feedback. - 15 mins

1. Birds in cities are now singing more ___.
   1. loudly
   2. slowly
   3. quickly
2. The birds are damaging their ___.
   1. mouths
   2. vocal cords
   3. ears
3. Some birds now sing ___.
   1. at night time
   2. late in the evening
   3. all the time
4. Urban and rural birds might not be able to ___ each other.
   1. recognise
   2. live with
   3. communicate with
5. Some species of birds may have a ___ gene pool.
   1. bigger
   2. stronger
   3. weaker
6. Male birds may be less attractive to females because their song sounds ___.
   1. higher
   2. worse
   3. quieter
7. Listening to birdsong can help people to reduce their ___.
   1. blood pressure
   2. weight
   3. smoking

Discuss whether students think the ideas in the article are true. Do birds sing more loudly in the cities? Have other animals changed their behaviour in the cities? - 6 mins

Write up the word "genes" from the article. Do they know a word with the same pronunciation? - "jeans". Explain this is a homophone. Elicit examples eg four/for, write/right. Ask students to underline the words below in the text. Check the pronunciation. In groups students think of homophones for these words. Help with the more difficult ones. - 15 mins

• Paragraph 1: their (there/they're), by (buy/bye), to(too/two).
• Paragraph 2: new (knew), male (mail), which (witch), some (sum), nighth(knight).
• Paragraph 3: so (sew/sow), be (bee), weak (week).