Navigation Links
Hoopoes' eggs show their true colors

Hoopoe females use cosmetics on their eggs - and the eggs gradually change color when they are incubated, from bluish-grey to a more saturated greenish-brown. This happens because secretion from the uropygial or preen gland a substance birds use to preen and protect their feathers is transfered from the female hoopoe's gland to her eggs directly with the bill and by means of belly feathers. This is one of the findings from a study led by Juan J. Soler of the Estacin Experimental de Zonas ridas, CSIC in Spain, published in Springer's journal Naturwissenschaften - The Science of Nature.

Previous work by Solers team has shown that the preen gland secretion of incubating hoopoes is brown in color and holds antimicrobial properties. The color is thanks to a combination of symbiotic bacteria found in the uropygial gland that provides protection against pathogenic bacteria. The symbiotic bacteria help to protect embryos from trans-shell infections, and in vitro are highly effective against Bacillus licheniformis, a well-known feather-degrading bacterium. The darker the color of the secretion, the more of the "good" bacteria are present and the better protection there is against the "bad" bacteria to ensure that a bird's embryos or feathers stay healthy.

To find out if indeed it is the gland secretion that causes hoopoes' eggs to change color, Soler's team conducted field studies in southern Spain and experimental work at the University of Granada and in Finca Experimental la Hoya in Almeria. In some cases, the researchers blocked off female hoopoes' uropygial glands found over their tails, to make it impossible for them to spread any preen oil onto their feathers or eggs. In other instances, the researchers smeared eggshells with this preen oil.

Their experimental tests showed that eggs that came into contact with the gland secretion changed color from their initial bluish-grey to greenish-brown. Eggs that were not covered with this so-called preen oil showed no color change.

"The eggshell coloration of hoopoe eggs is the consequence of the female birds' spreading uropygial secretion on the eggshells," says Soler.

The researchers speculate that the egg coloration might be a way through which a female hoopoe signals to the male that she is good breeding material, for future reference. It can inform a male of the presence, abundance, or even particularities of the antimicrobial bacterial community found in a female's glands qualities that she will be able to carry over to their offspring should they mate in the future. Males can use this information to adjust their investment in the actual breeding attempt. Although further experimental work is needed to establish the validity of this signaling hypothesis, Soler hopes that the new results will encourage such research in hoopoes and in other birds.

Contact: Laura Zimmermann

Related biology news :

1. 2 servings of salmon a week is healthy for pregnant women and their babies
2. Study finds peoples niceness may reside in their genes
3. Lizard moms may prepare their babies for a stressful world
4. Deterring signals: Tobacco plants advertise their defensive readiness to attacking leafhoppers
5. Vampire jumping spiders identify victims by their antennae
6. New Tool Helps Drug Developers Optimize Their Research and Target Development for Better Results and a Stronger Competitive Edge
7. Parasitic plants steal genes from their hosts
8. Cougars are re-populating their historical range, new study confirms
9. Research: Many programs to help diabetics manage their health do work
10. Better looking birds have more help at home with their chicks
11. The old primates club: Even male monkeys ride their fathers coattails to success
Post Your Comments:
(Date:11/4/2015)... 2015 --> ... by Transparency Market Research "Home Security Solutions Market - Global ... - 2022", the global home security solutions market is expected to ... The market is estimated to expand at a CAGR ... 2022. Rising security needs among customers at homes, the ...
(Date:10/29/2015)... , Oct. 29, 2015   MedNet Solutions ... the entire spectrum of clinical research, is pleased to ... High Tech Association (MHTA) as one of only three ... the "Software – Small and Growing" category. The Tekne Awards ... who have shown superior technology innovation and leadership. ...
(Date:10/29/2015)... Va. , Oct. 29, 2015 Daon, ... today that it has released a new version of ... customers in North America have ... IdentityX v4.0 also includes a FIDO UAF certified ... are already preparing to activate FIDO features. These customers ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... -- Clintrax Global, Inc., a worldwide provider of clinical research services headquartered ... the company has set a new quarterly earnings record in Q3 ... posted for Q3 of 2014 to Q3 of 2015.   ... , with the establishment of an Asia-Pacific ... United Kingdom and Mexico , with ...
(Date:11/24/2015)... ... November 24, 2015 , ... This fall, global software ... events in five states to develop and pitch their BIG ideas to improve health ... state are competing for votes to win the title of SAP's Teen Innovator, an ...
(Date:11/24/2015)... 24, 2015 SHPG ) announced today that ... Piper Jaffray 27 th Annual Healthcare Conference in ... at 8:30 a.m. EST (1:30 p.m. GMT). --> SHPG ... will participate in the Piper Jaffray 27 th Annual Healthcare ... Tuesday, December 1, 2015, at 8:30 a.m. EST (1:30 p.m. GMT). ...
(Date:11/24/2015)... 2015  Tikcro Technologies Ltd. (OTCQB: TIKRF) today announced that its Annual ... 11:00 a.m. Israel time, at the law offices ... Street, 36 th Floor, Tel Aviv, Israel . ... and Izhak Tamir to the Board of Directors; , ... , approval of an amendment to certain terms of options granted ...
Breaking Biology Technology: