Dr. Mark E. Clark, associate professor, and Dr. Wendy Reed, head of biological sciences at NDSU, found in their study that embryos in eggs appear to sense external environments and adjust how they develop. The research is being published in Functional Ecology, a British Ecological Journal, available in early view online.
Franklin’s gull is a bird that migrates long distances and requires precise timing. It winters along the west coast of South America until returning to the prairie wetlands of North America, where it nests in large colonies come springtime. The dark hood, gray wings and pink-tinted breast are a harbinger of spring to the people of the Northern Great Plains, who affectionately call it the prairie rose gull. Soon after large wetlands thaw, Franklin’s gulls arrive to build floating nests from wetland vegetation to hold three green-and-black speckled eggs.
Inside these dark eggs, the developing chicks also sense spring days. “The growing embryos integrate signals from the nutrients provided to eggs by mothers with the amount of daylight,” said Dr. Clark. “The signals let the chick know whether the egg was laid at the beginning, or at the end of the nesting period.”
Clark and Reed note that chicks from eggs produced at the beginning of nesting take longer to hatch, but are larger than chicks from eggs laid at the end of nesting. Contrast that with eggs laid at the end of the nesting period, which hatch in less time, but at a smaller size.
“Chicks hatching later in the season have less time to grow, less time to become independent, and less time for flying lessons before they must migrate to South America in the fall,” said Dr. Reed.
According to Dr. Clark, data indicate embryos in late season eggs appear to be sensing external environments and adjusting their development. These changes in development time and size may be important for chicks to successfully migrate.
Many birds, including Franklin’s gulls, are arriving earlier on their breeding grounds. “This research suggests that the impacts of changing seasonal signals have far reaching effects on bird biology, including chick development,” said Dr. Clark.
Researchers evaluated the ability of avian embryos to integrate cues of season from photoperiod and maternal environments present in eggs to produce season variation among phenotypes among Franklin’s gull (Leucophaeus pipixcan) hatchlings.Field research was conducted at the J. Clark Salyer National Wildlife Refuge and Lake Alice National Wildlife Refuge in north-central North Dakota along the Souris River.
Researchers collected early and late season eggs, separating some into component parts and incubating others for short or long photoperiods. Upon hatching, chicks were evaluated for size and yolk sac reserves.
Results of the study show that hatchling size is sensitive both to egg contents provided by mothers and to photoperiod, and development time increases across the season. When cues of season from eggs are mismatched with cues from photoperiod, alternate phenotypes are created.
Clark and Reed also found that seasonal variation in egg size, yolk, albumen or shell content of the eggs does not account for the seasonal maternal egg effect on hatchling size. “We expect our results to initiate new studies on how vertebrate embryos integrate environmental cues with maternal effects and offspring responses to optimize the expression of offspring phenotype,” said Clark.
Previous NDSU graduate students who participated in the research include Shawn Weissenfluh and Emily Davenport-Berg. Other NDSU students who assisted in the research include Nathaniel Cross, Peter Martin, Dan Larsen, Michelle Harviell and Andrew Nygaard, along with Petar Miljkovic from Grinnell College.
Research funding was provided by the National Science Foundation (IOS-0445848), the North Dakota Game and Fish Department and the U.S. Fish and Wildlife Service.
North Dakota State University, Fargo, is a student focused, land-grant, research university – an economic engine that educates students, conducts primary research, creates new knowledge and advances technology. NDSU is among the top 108 universities in the country with very high research activity, as determined by the Carnegie Commission on Higher Education.
A British Ecological Society journal, Functional Ecology publishes high impact papers on organismal ecology, including physiological, behavioural and evolutionary ecology.
Carol Renner | Newswise Science News
NUI Galway highlights reproductive flexibility in hydractinia, a Galway bay jellyfish
24.02.2020 | National University of Ireland Galway
Shaping the rings of molecules
24.02.2020 | University of Montreal
The operational speed of semiconductors in various electronic and optoelectronic devices is limited to several gigahertz (a billion oscillations per second). This constrains the upper limit of the operational speed of computing. Now researchers from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, and the Indian Institute of Technology in Bombay have explained how these processes can be sped up through the use of light waves and defected solid materials.
Light waves perform several hundred trillion oscillations per second. Hence, it is natural to envision employing light oscillations to drive the electronic...
Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.
Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...
Investigation of the temperature dependence of the skyrmion Hall effect reveals further insights into possible new data storage devices
The joint research project of Johannes Gutenberg University Mainz (JGU) and the Massachusetts Institute of Technology (MIT) that had previously demonstrated...
Researchers at Chalmers University of Technology, Sweden, recently completed a 5-year research project looking at how to make fibre optic communications systems more energy efficient. Among their proposals are smart, error-correcting data chip circuits, which they refined to be 10 times less energy consumptive. The project has yielded several scientific articles, in publications including Nature Communications.
Streaming films and music, scrolling through social media, and using cloud-based storage services are everyday activities now.
After helping develop a new approach for organic synthesis -- carbon-hydrogen functionalization -- scientists at Emory University are now showing how this approach may apply to drug discovery. Nature Catalysis published their most recent work -- a streamlined process for making a three-dimensional scaffold of keen interest to the pharmaceutical industry.
"Our tools open up whole new chemical space for potential drug targets," says Huw Davies, Emory professor of organic chemistry and senior author of the paper.
12.02.2020 | Event News
16.01.2020 | Event News
15.01.2020 | Event News
24.02.2020 | Life Sciences
24.02.2020 | Materials Sciences
24.02.2020 | Earth Sciences