Their study, published this month in of the Journal of Comparative Physiology B, shows that crest size may be a physical indicator of a male crested auklet’s quality as a mate.
Scientists have long noted that female auklets prefer males with larger crests. But until recently, they did not know why. Low levels of stress hormones in males with larger crests indicate that they cope better with the stresses of reproduction, such as finding food, competing with thousands of other birds for mates and nest sites, and helping rear chicks.
“Females will divorce shorter-crested mates for the opportunity to mate with longer-crested males. Our study suggests that longer-crested males could contribute more to reproductive success because they have greater capacity to meet the social and physiological costs,” said Hector Douglas, assistant professor of biology at the Kuskokwim Campus in Bethel.
Douglas and collaborator Alexander Kitaysky, an associate professor at the UAF Institute of Arctic Biology, say their results fit into a larger theory about animal societies.
“There appears to be a social hierarchy at the colony which is correlated with the size of the male ornament and this, in turn, is related to the levels of stress hormones,” Douglas said. “The cost of attaining and maintaining dominant status is reflected in the animals’ physiology and this has a distinct pattern in the society.”
Douglas and his field team studied the small, sooty-gray seabirds during fieldwork on Big Koniuji in the Shumagin Islands in the Aleutian Chain during June and July of 2002. They captured and measured the auklets at a mountainside colony and collected blood samples. Kitaysky’s lab analyzed the blood samples for the stress hormone corticosterone. They found that larger crests correlated with lower levels of corticosterone in the males’ bloodstream.
“Theoretically males that have a lower level of baseline stress hormone have a greater capacity to respond to additional stress,” Douglas said. “The males with the larger crests had markedly lower levels of corticosterone and therefore they should be better mates. We suspect that crest size is an outward indicator of intrinsic quality, and the data on hormones appears to confirm this.”
The project was funded by the Eppley Foundation for Research Inc. and the Angus Gavin Memorial Bird Research Fund, through the University of Alaska Foundation. The Alaska Sea Grant College Program and the Center for Global Change and Arctic System Research provided additional logistical support.
CONTACT: Hector Douglas, assistant professor of biology, at 907-543-4589 or via e-mail at firstname.lastname@example.org. Marmian Grimes, UAF public information officer, at 907-474-7902 or via e-mail at email@example.com.
Marmian Grimes | EurekAlert!
The importance of biodiversity in forests could increase due to climate change
17.11.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
Win-win strategies for climate and food security
02.10.2017 | International Institute for Applied Systems Analysis (IIASA)
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
20.11.2017 | Earth Sciences
20.11.2017 | Physics and Astronomy
17.11.2017 | Physics and Astronomy