But the bill can play an important role in regulating the bird's body temperature by acting as a radiator for excess heat. A team of scientists have found that because of this, high summer temperatures have been a strong influence in determining bill size in some birds, particularly species of sparrows that favor salt marshes. The team's findings are published in the scientific journal Ecography, July 20.
Scientists at the Smithsonian Migratory Bird Center at the Smithsonian's Conservation Biology Institute and colleagues examined five species of sparrow that inhabit salt marshes on the East, West and Gulf coasts of North America. While these marshes are very similar in makeup and structure, the main difference among them is summer temperatures. Focusing on 10 species and subspecies of tidal salt marsh sparrow, the team measured 1,380 specimens and found that the variation in the sparrows' bill size was strongly related to the variation in the daily high summer temperatures of their salt marsh breeding habitats—the higher the average summer temperature, the larger the bill. Birds pump blood into tissue inside the bill at high temperatures and the body's heat is released into the air. Because larger bills have a greater surface area than smaller bills, they serve as more effective thermoregulatory organs under hot conditions. On average, the study found the bills of sparrows in marshes with high summer temperatures to be up to 90 percent larger than those of the same species in cooler marshes."It is known that blood flow is increased in poorly insulated extremities in some animals, like a seal's flippers, a rabbit's ears and the wattles of a turkey helping hot animals to cool down. The bill of a bird can function in much the same way allowing birds to dump heat," said Russ Greenberg, director of the Smithsonian Migratory Bird Center and lead author of the research. "Being able to cool down and not loose excess body moisture is particularly important since these birds live in an environment with direct sun and limited access to fresh water."
The research team is working with physiologists from Brock University in Canada, employing thermal imaging to develop a more detail picture of how song sparrows that live in dunes and marshes along the Atlantic coast use their bills to stay cool.
John Gibbons | EurekAlert!
Signaling Pathways to the Nucleus
19.03.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau
In monogamous species, a compatible partner is more important than an ornamented one
19.03.2018 | Max-Planck-Institut für Ornithologie
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
19.03.2018 | Event News
19.03.2018 | Information Technology
19.03.2018 | Interdisciplinary Research