The behaviour of semipalmated sandpipers (Calidris pusilla) feeding during low tide in the Bay of Fundy, New Brunswick, surprised Guy Beauchamp, an ornithologist and research officer at the University of Montreal's Faculty of Veterinary Medicine.
Sandpipers exhibit different feeding behavior depending on position in group.
Credit: University of Montreal
While individuals on the periphery remained alert and used short pecks to feed on the mudflats, birds in the middle of the group relaxed their vigilance and fed on a different resource. The more peripheral group members were effectively used as sentinels for the others.
Two observation seasons were needed to confirm this never-before-documented behaviour. The phenomenon attracted the attention of Britain's Royal Society, which has just published the results of Beauchamp's research in the most recent edition of its Biology Letters. "Both foraging modes are easy to distinguish," Beauchamp explained. "In the first case, the birds keep their heads upright while pecking at their food rapidly; they are on the lookout for predators. In the second case, their heads are kept low while they scrape the mud in search of tiny organisms."
Scientists know that living in groups provides individuals with added protection and increases their chances of survival. Beauchamp's discovery provides further information about the precise mechanisms that lead to this advantage. Peripheral birds must be on the lookout for predators (in this case mainly the silhouettes of falcons, which can strike the sandpipers at any moment), allowing the central birds to use different resources. "During their stopover in eastern Canada, sandpipers must optimize their strength to continue their migration. Any advantage helps," Beauchamp said.It took two sessions of three weeks in the field, in 2011 and 2012, for the biologist to confirm these observations. He observed 466 birds in 43 flocks before drawing his conclusions. They feed on biofilm, which requires a dangerous relaxing of vigilance that is really only possible in the safest part of the group. Biofilm refers to the smorgasbord of diatoms and phytoplankton that sandpipers filter in their beaks in a back-and-forth movement. Their other form of diet consists of amphipods, which the wading birds capture after spotting them visually.
William Raillant-Clark | EurekAlert!
How molecules teeter in a laser field
18.01.2019 | Forschungsverbund Berlin
Discovery of enhanced bone growth could lead to new treatments for osteoporosis
18.01.2019 | University of California - Los Angeles
The scientific and political community alike stress the importance of German Antarctic research
Joint Press Release from the BMBF and AWI
The Antarctic is a frigid continent south of the Antarctic Circle, where researchers are the only inhabitants. Despite the hostile conditions, here the Alfred...
World first experiments on sensor that may revolutionise everything from medical devices to unmanned vehicles
The new sensor - capable of detecting vibrations of living cells - may revolutionise everything from medical devices to unmanned vehicles.
Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.
In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...
Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.
It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:
The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.
One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...
16.01.2019 | Event News
14.01.2019 | Event News
12.12.2018 | Event News
18.01.2019 | Materials Sciences
18.01.2019 | Life Sciences
18.01.2019 | Health and Medicine