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!
When Air is in Short Supply - Shedding light on plant stress reactions when oxygen runs short
23.03.2017 | Institut für Pflanzenbiochemie
WPI team grows heart tissue on spinach leaves
23.03.2017 | Worcester Polytechnic Institute
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
23.03.2017 | Life Sciences
23.03.2017 | Power and Electrical Engineering
23.03.2017 | Earth Sciences