Skip to content

Nature

Birdsong proves geographical races have different responses.

by Dave Armstrong 30 Nov 2014
Birdsong proves geographical races have different responses.

The stonechat is loved in many countries for his chirpy song and the fact that he heralds the summer in wild places. Here, the true success of the species over Africa, Asia as far as Siberia and Europe can be better understood by using the song and plumage as discriminating features for sexual selection. Scottish stonechat image; Credit: © Shutterstock

Geographically, the stonechat Saxicola torquata (or rubicola) has a variety of sexually selected traits, such as its appearance and its song. There were significant differences found in Kim G Mortega, Heiner Fllinks and Barbara Helm’s study published in Frontiers in Zoology as- Behavioural response of a migratory songbird to geographic variation in song and morphology. The 3 authors work at the Max Planck Institute for Ornithology in Radolfzell, Germany and the Universities of Konstanz and Glasgow.

These sexually-selected traits are important for evolutionary diversification. Males are chosen for their songs by receptive females but each species has a different relevance for the song. Acoustic and visual signalling differ geographically, leading to a behavioural barrier to breeding and hence speciation. Migratory birds have yet another factor thrown into the mix, although the songs can be acquired quickly. Hens, for example, may have to choose their mates more quickly than species which are residents. Song may therefore contribute to geographical variation more than inherited morphological traits.

This study involved playback of songs to both sexes, also using decoys. Local stimuli of appropriate decoys and songs produced stronger responses for males and females, but especially for the acoustic stimuli. Reproductive isolation does seem a likely end-result for such geographical mating barriers, although the results indicate a cline whereby the 2 extremes would tend not to mate, but intermediates could recognise the sounds as mating calls and respond at least partly.

Vocal learning is the key to this research, as the natal region provides the mix of song types that would be acceptable to a mate. Imperfect copying could be the reason for local variations, just as in any language. So we can talk of song dialects. The experimentation involved is by studying copulation and solicitation displays after standardised playback. The offspring from a mating between local birds would be better equipped to deal with local ecologies. One of the most interesting experiments was to try out the closely related African stonechat, which has the same Latin name at the moment. The male response was dramatic, as they obviously had fine discrimination between attractive local competitors and those from further away.

The answer for a lost individual after mating would be to learn a new song or how to react to novel stimuli such as the song in the case of females. Nightingales have been shown to learn new songs in their first season, (see our old The Nightingale Sings story on Sarah Kiefer’s paper), so the migratory problem seem to be overcome in some cases. Local stonechat males of course might have something to say about these interlopers! The point is that colour and other morphological characters also aid in discrimination, so it’s not the song, it’s the singer.


Trending Eco-Friendly Clothing

Love My Planet Women's Relaxed Fit Hoodie
Earth
Quick Add
Close
Notify me
Notify me
Love My Planet Women's Relaxed Fit Hoodie
Love My Planet women's eco-friendly relaxed fit hoodieSize Guide Centimeters 8 10 12 14 16 18 Bust 84 88 92 97 103 108 Waist 66 70 75 80 85 91 Hips 91 95 99 104 109 116 Bust: Measure around the fullest part of...
£38.00
£38.00
Close
Notify me
Notify me
Penguins Hate Push-Ups Men's Pullover Hoodie
Earth
Quick Add
Close
Notify me
Notify me
Penguins Hate Push-Ups Men's Pullover Hoodie
Penguins Hate Push-Ups men's eco-friendly pullover HoodieSize Guide Centimeters XS S M L XL XXL Height 171 175 179 183 189 195 Chest 86 93 99 104 116 129 Waist 71 76 81 89 99 112 Chest: Measure all round your chest just below...
£38.00
£38.00
Close
Notify me
Notify me
Lightning Bolt Kids Long Sleeve T-Shirt
Earth
Quick Add
Close
Notify me
Notify me
Notify me
Lightning Bolt Kids Long Sleeve T-Shirt
Lightning Bolt kids eco-friendly long sleeve t-shirtSize Guide Centimeters 3-4yrs 5-6yrs 7-8yrs 9-10yrs 11-12yrs Height 98 112 125 136 147 Chest 60 66 70 75 84 Chest: Measure all around your chest just below your armpits. Height: Your natural height If you fall between...
£18.00
£18.00
Close
Notify me
Notify me
Notify me
Union Jack Tote Bag
Earth
Quick Add
Close
Notify me
Notify me
Union Jack Tote Bag
Union Jack eco-friendly colour tote bagProduct Specification Organic Cotton Tote Bag. Twill Weave (170gsm). 37 x 42 cm (7cm gusset.) Made in India / Designed on the Isle of Wight. Wash Cool, Hang Dry.
£16.00
£16.00
Close
Notify me
Notify me
Prev Post
Next Post

Eco-Friendly Shop

Women's Clothing

Eco-Friendly Clothing for Women Our online shop offers a wide range of sustainable women’s clothing products, including t-shirts, hoodies, vests, sweaters, shorts, and...
Shop Now

Men's Clothing

Eco-Friendly Clothing for Men Our online shop offers a wide range of sustainable men’s clothing products, including t-shirts, hoodies, vests, sweaters, shorts, and...
Shop Now

Kids Clothing

Eco-Friendly Clothes for Kids Our online shop offers a wide range of sustainable kids clothing products, including t-shirts, hoodies and jumpers. Our garments...
Shop Now
Someone recently bought a
[time] ago, from [location]

Thanks for subscribing!

This email has been registered!

Shop the look

Choose Options

Earth Times
Sign up for exclusive updates, new arrivals & insider only discounts

Recently Viewed

Edit Option
Back In Stock Notification
this is just a warning
Login
Shopping Cart
0 items

Before you leave...

Take 20% off your first order

20% off

Enter the code below at checkout to get 20% off your first order

CODESALE20

Continue Shopping