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
Complex genetic regulation of flowering time
26.05.2020 | Christian-Albrechts-Universität zu Kiel
Bristol scientists see through glass frogs' translucent camouflage
26.05.2020 | University of Bristol
Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.
researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...
Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.
When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...
Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.
Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...
Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.
A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...
By studying the chemical elements on Mars today -- including carbon and oxygen -- scientists can work backwards to piece together the history of a planet that once had the conditions necessary to support life.
Weaving this story, element by element, from roughly 140 million miles (225 million kilometers) away is a painstaking process. But scientists aren't the type...
19.05.2020 | Event News
07.04.2020 | Event News
06.04.2020 | Event News
26.05.2020 | Physics and Astronomy
26.05.2020 | Life Sciences
26.05.2020 | Information Technology