Navigation Links
How birds spot the cuckoo in the nest
Date:7/15/2008

It's not always easy spotting the cuckoo in the nest. But if you don't, you pay a high price raising someone else's chick. How hosts distinguish impostor eggs from their own has long puzzled scientists. The problem remained largely unsolved while looking at it through our own eyes. It was only when people started thinking from the birds' perspective that they began to understand how hosts recognise a cuckoo egg in the nest. Marcel Honza from the Academy of Sciences of the Czech Republic explains that birds see UV wavelengths that are well outside our own visual range. Knowing that many bird eggs reflect UV wavelengths, Honza wondered whether altering the reflected UV spectrum of an egg would affect a bird's ability to recognise it as foreign and reject it. Would a blackcap recognise and evict an impostor egg if the reflected UV spectrum were different from the wavelengths reflected by the bird's own clutch? Teaming up with Lenka Polačikov, Honza headed into a near-by forest to test blackcap responses to impostor eggs and publish their findings on July 18th in The Journal of Experimental Biology at http://jeb.biologists.org.

But instead of testing the birds' reactions to real cuckoo eggs, the team found abandoned blackcap eggs, introducing them as impostors to successful blackcap clutches. Having identified nests with well-established clutches, the team coated some impostor eggs in UV blocker, to alter their UV appearance, and others in Vaseline, which didn't alter the egg's UV reflectivity, before planting the impostors in their new nest. Then the team kept their fingers crossed, hoping that the nests weren't washed out by a heavy downpour or raided by a hungry predator, as they waited 5 days to see if the parents rejected the interlopers.

Of the 16 eggs coated in Vaseline, 11 of the impostors were accepted by the nesting parents, while five were rejected; most of the interloper blackcap eggs were visually indistinguishable from the nesting parents' own eggs and were accepted as belonging to the brood. However, it was a different matter for the birds sitting on UV-block-coated impostors. Seventeen brooding parents evicted the strange looking egg, pecking at the shell until they had made a large enough hole to stick their beak in and carry it away. Only 11 blackcaps accepted the interloper with its altered appearance.

The UV appearance of the eggs was very important in enabling the blackcaps to recognise the new eggs as impostors. The blackcaps rejected far more eggs when Polačikov and Honza covered them in UV block. By altering the eggs' UV reflectivity the team had made them stand out from the crowd.

Honza admits that he was surprised that the UV reflectivity had such a significant effect on the blackcap's ability to reject an impostor. Having found that an interloper's UV appearance is key to its acceptance in a clutch, Honza is keen to see whether cuckoos try to outsmart their victims by choosing clutches that closely match their own eggs' UV reflectivity.


'/>"/>

Contact: Kathryn Phillips
kathryn@biologists.com
44-122-342-5525
The Company of Biologists
Source:Eurekalert

Related biology news :

1. Birds migrate together at night in dispersed flocks, new study indicates
2. Want to fly? Dont copy the birds and the bees
3. Killer whales, blind bats, discriminating dolphins, mating birds
4. Migrating songbirds learn survival tips on the fly
5. Birds migrate earlier, but some may be left behind as the climate warms rapidly
6. Bee species outnumber mammals and birds combined
7. Genetic sequencing of protein from T. rex bone confirms dinosaurs link to birds
8. Asian waterbirds stage remarkable comeback
9. Some migratory birds cant find success in urban areas, study finds
10. Birds, bats and insects hold secrets for aerospace engineers
11. High degree of resistance to antibiotics in Arctic birds
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/15/2016)... 2016  There is much more to innovative access ... engine. Continental will demonstrate the intelligence of today,s solutions ... . Through the combination of the keyless entry and ... elements, the international technology company is opening up new ... "The integration of biometric elements brings our ...
(Date:12/12/2016)...  Researchers at Trinity College, Dublin, are opening ... the material with Silly Putty. The mixture (known as ... to sense pulse, blood pressure, respiration, and even ... The research team,s findings were published Thursday ... http://science.sciencemag.org/content/354/6317/1257 ...
(Date:12/8/2016)... Calif. , Dec. 8, 2016  Singulex, Inc., ... Molecule Counting technology, entered into a license and supply ... serving science. The agreement provides Singulex access to Thermo ... Europe is used to diagnose systemic ... United States to aid in assessing the ...
Breaking Biology News(10 mins):
(Date:1/23/2017)... England , January 23, 2017 ... today announces completion of its Series D financing, raising $35 ... one new investor, Wondfo Biotech. ... Development of the Atlas Genetics io® ... the Chlamydia trachomatis (CT) test announced in February 2016.  This ...
(Date:1/21/2017)... ... January 20, 2017 , ... G&L ... the healthcare industry ( http://www.gandlscientific.com ), has announced the opening of new offices ... and scientific consultants and contractors. This is the latest step in G&L’s expansion ...
(Date:1/21/2017)... , Jan. 20, 2017 Aratana Therapeutics, ... company focused on the licensing, development and commercialization of ... Pharm,s Best Company in North America ... the award based on the FDA approval ... (grapiprant tablets), ENTYCE ® (capromorelin oral solution) and ...
(Date:1/20/2017)... January 20, 2017 http://www.Financialbuzz.com ... one of leading causes of death worldwide. There were ... number of cancer related deaths increased gradually over time, ... incidence rate of various cancers continues to drive demand ... report by Global Market Insights, Inc. cancer biological therapy ...
Breaking Biology Technology: