Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Migration takes guts

07.07.2003


Birds modify digestive physiology during migration



When birds migrate over long distances to and from their breeding grounds, it takes more than strong flight muscles and an innate knowledge of where they’re going. According to a University of Rhode Island researcher, migration also takes guts.

Several studies conducted by URI physiological ecologist Scott McWilliams have shown that birds have a flexible digestive system that they modify to meet the changing energy demands of migration.


"The gut of a migratory bird is a really dynamic organ. In preparation for migration, the gut increases in size tremendously over several days," McWilliams said. "It expands, its cells get larger and it produces new cells so the bird can dramatically increase its food intake and store up energy for the long flight."

But because the digestive system is one of the most metabolically active tissues in the body and it consumes a great deal of energy, it shuts down during migration so more energy can be diverted to fueling flight. This partial atrophy of their digestive system affects birds when they stop to feed at sites along their migration route. McWilliams says that because their digestive system is shut down, the birds must eat less until their gut becomes acclimated and can operate efficiently again.

"We’ve known for many years that birds recovering from a migration flight do not immediately regain body mass, but we didn’t know why. Now it’s clear that this digestive constraint is responsible for the delay and likely affects the pace of a bird’s migration," said the Kingston resident.

One important result of McWilliams’ research is a new understanding of the protein requirements of migratory birds. Ornithologists have long believed that a diet high in energy was all that was necessary to sustain migratory flight. But the URI researcher said that proteins are also needed to build the digestive tract. This need for protein may have a significant impact on habitat management at key migratory stop-over sites.

"To build their digestive tract, birds need foods available in the environment that have sufficient protein," McWilliams said. "When birds feed only on fruits that are high in fat and low in protein, they may have to delay their migration. To help birds ensure a successful migration, we need to ensure, for example, that shrubs along their migratory routes have fruits with higher protein amounts."

Little is known about the nutrients in wild fruits, so McWilliams’ current research is aimed at identifying the shrub species that bear fruit with high protein and energy content.

Funded by the National Science Foundation and the U.S. Department of Agriculture, and with logistical support provided by The Nature Conservancy, McWilliams’ field studies have involved both free-living and captive birds, mostly white-throated sparrows, red-eyed vireos and yellow-rumped warblers. He and his students work each fall on Block Island, R.I. measuring the dynamics of body mass, body composition and gut size of wild songbirds as they stop there during migration. Using experiments with captive birds, he has also examined the physiological effects of short-term fasting, which most birds experience during migration, and then observed the feeding delay that occurs when the birds were then allowed to eat as much as they wanted.

McWilliams began studying the physiology of birds as a graduate student at the University of California at Davis in the early 1990s. He joined the faculty of URI’s Department of Natural Resources Science in 1998 after a three-year postdoctoral fellowship at the University of Wisconsin at Madison.

"Migration is very costly to birds," said McWilliams. "But just like people who exercise to modify aspects of their bodies, birds can modify their bodies too so they can accomplish the formidable feats of endurance required by migration."

Todd McLeish | EurekAlert!
Further information:
http://www.uri.edu/

More articles from Life Sciences:

nachricht The first genome of a coral reef fish
29.09.2016 | King Abdullah University of Science and Technology

nachricht New switch decides between genome repair and death of cells
27.09.2016 | University of Cologne - Universität zu Köln

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

HLF: From an experiment to an establishment

29.09.2016 | Event News

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

Laser use for neurosurgery and biofabrication - LaserForum 2016 focuses on medical technology

27.09.2016 | Event News

 
Latest News

New Multiferroic Materials from Building Blocks

29.09.2016 | Materials Sciences

Silicon Fluorescent Material Developed Enabling Observations under a Bright “Biological Optical Window”

29.09.2016 | Materials Sciences

X-shape Bio-inspired Structures

29.09.2016 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>