Some 100 species of birds are what scientists call "obligate brood parasites"--instead of building nests and raising their own young, they lay their eggs in the nests of other species and let those birds do the hard work of parenting for them. The black-headed duck of South America is one of these, but it stands out from all the others in a striking way. Black-headed ducks dont need any parental care other than incubation for their eggs--the ducklings leave the nest one day after hatching and paddle off into the reeds to fend for themselves.
"There doesnt seem to be much if any cost to the host species, so you wouldnt expect there to be much pressure on the hosts to evolve defenses against this kind of parasitism," said Bruce Lyon, a professor of ecology and evolutionary biology at the University of California, Santa Cruz.
When Lyon and John Eadie of UC Davis set out to study the black-headed ducks, they expected to find a highly successful brood parasite, unopposed by the antagonistic strategies that host species deploy against more costly parasites like cuckoos and cowbirds. Instead, they found that black-headed duck eggs are often rejected from host nests, and it took four years of detailed field research to figure out why. Lyon and Eadie published their findings in the November 18 issue of the journal Nature. The key breakthrough was their discovery that each of the black-headed ducks two main host species--the red-gartered coot and red-fronted coot--were busy parasitizing the nests of their own species. The black-headed ducks were being thwarted by defenses that had evolved as a result of brood parasitism among the coots themselves.
Tim Stephens | EurekAlert!
The dense vessel network regulates formation of thrombocytes in the bone marrow
25.07.2017 | Rudolf-Virchow-Zentrum für Experimentelle Biomedizin der Universität Würzburg
Fungi that evolved to eat wood offer new biomass conversion tool
25.07.2017 | University of Massachusetts at Amherst
Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers
Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...
Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.
At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...
3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects
A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
21.07.2017 | Event News
19.07.2017 | Event News
12.07.2017 | Event News
25.07.2017 | Physics and Astronomy
25.07.2017 | Earth Sciences
25.07.2017 | Life Sciences