Plant populations in wetland areas face increasing isolation as wetlands are globally under threat from habitat loss and fragmentation. Erik Kleyheeg and Merel Soons of Utrecht University show that the daily movement behaviour of wintering mallards is highly predictable from the landscape they live in and that their daily flights contribute to maintaining the connections between wetland plant populations across increasingly fragmented landscapes. The researchers and co-authors are publishing their results today in the academic journal Journal of Ecology.
Mallards are among the most numerous and widespread duck species in the world, their global population estimated at approximately 19 million individuals. They are strong flyers, able to cover long distances at great speed (about 80 km/h) and part of the population migrates over long distances from their breeding areas to their wintering areas.
Landscapes with numerous waterbodies are inhabited by large numbers of mallards, who each visit their favourite feeding sites at night and share a common roost during the day. They connect wetlands by dispersing seeds over short distances. Landscapes with more sparse waterbodies are inhabited by fewer mallards, who fly between their more scattered feeding sites at night and connect wetlands by dispersing seeds over much longer distances.
Credit: Utrecht University
Mallards are omnivorous and in their non-breeding range, during autumn and winter, they feed largely on plant seeds. Many of these seeds are not digested and survive gut passage. In this way, the mallards play an important role in transporting the seeds between wetland feeding and resting areas.
Effects of the landscape on mallard behaviour
Analysis of the movement behaviour of individual mallards carrying a GPS data-logger revealed that the daily movement patterns of wintering mallards are remarkably predictable. Mallards typically spend the daytime resting on a common roost, usually a large open water body. At night, they leave the roost to forage in and around wetland areas and agricultural fields, visiting 2-4 of such areas per night.
Surprisingly, they have very high site fidelity and return to the same sites almost every night. This foraging behaviour remains similar across a wide range of landscapes. As a result, mallards have small home ranges and travel short distances between foraging sites in landscapes with many wetlands, while they have larger home ranges and travel much longer distances per night in landscapes with few and sparse wetlands.
Connectivity between plant populations maintained
Through these daily movements, mallards connect the wetlands in the landscapes they inhabit. Model calculations combining information on mallard movement behaviour, plant and seed traits and landscape configuration estimate that about 34% of seeds surviving digestion are dispersed towards roost areas, which may function as regional reservoir for plant biodiversity.
About 7% of surviving seeds are dispersed between foraging areas. The seeds most likely to be dispersed are small, hard seeds, which are best able to withstand the mechanical digestion in the birds' gizzard. Given the large numbers of seeds mallards ingest on a daily basis, they are likely to greatly contribute to plant dispersal and the connection between otherwise isolated plant populations across a wide range of landscapes.
E. Kleyheeg*, H.J. Treep*, M. de Jager*, B.A. Nolet and M.B. Soons* (2017) Seed dispersal distributions resulting from landscape-dependent daily movement behaviour of a key vector species. Journal of Ecology, online early DOI: 10.1111/1365-2745.12738.
*affiliated with Utrecht University
E. Kleyheeg*, J.B.G. van Dijk*, D. Tsopoglou-Gkina*, T. Woud*, D. Boonstra*, B.A. Nolet and M.B. Soons* (2017) Movement patterns of a keystone waterbird species are highly predictable from landscape configuration. Movement Ecology, online early DOI: 10.1186/s40462-016-0092-7.
* affiliated with Utrecht University
Nieske Vergunst | EurekAlert!
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences