Mature, unfragmented forests may offer refuge in a changing climate
Habitat alteration due to forest clearing and climate change threaten wildlife populations throughout the globe. To better understand the interacting effects of habitat degradation and climate on bird populations, researchers from the U.S. Forest Service Pacific Southwest Research Station (PSW), Klamath Bird Observatory, and Costa Rica Bird Observatories spent 12 years studying the White-collared Manakin, a fruit-eating tropical bird, in mature and young forests along the Caribbean coast of Costa Rica.
During the study, several El Niño and La Niña events--cycles of warm and cold ocean temperatures that influence air temperature and precipitation--resulted in very marked dry and wet annual conditions that allowed researchers to measure differences in manakin survival relative to climatic shifts. Results were recently published in the journal Oecologia.
In young tropical forests, researchers found dramatic decreases in manakins' survival during dry weather associated with El Niño. Researchers believe that, due to a sparser canopy and their fragmented nature, the young forests were more susceptible to understory drying that reduced fruit production.
Conversely, manakins' survival rates were higher during wet years associated with La Niña events in these young forests where increased moisture and sun exposure likely led to an abundance of fruit resources. In mature forests, researchers observed very stable manakin survival rates regardless of climatic shifts, suggesting a relatively constant abundance of fruit resources.
"The complex structure of mature forest is thought to serve as a climatic refuge, buffering fruiting plants from climatic changes resulting in stable manakin survival," says Jared Wolfe, a postdoctoral researcher with PSW and Klamath Bird Observatory and the study's lead author.
"Climatic refuges, such as mature tropical forests, may be important for many resident tropical bird species faced with the decreasing availability of mature forests coupled with increases in the severity of El Niño-associated dryness."
These study results represent the first published documentation of El Niño's influence on the survival of a resident tropical landbird. Researchers believe that variation in manakin survival between forest types provides insight into the sensitivity of certain species to habitat alteration.
"From a management perspective, understanding how climatic events affect biodiversity is critical for the development of science-based conservation strategies," says Pablo Elizondo, the Costa Rica Bird Observatories' executive director and co-author of the study.
To read the paper, visit: http://www.
Headquartered in Albany, Calif., the Pacific Southwest Research Station develops and communicates science needed to sustain forest ecosystems and other benefits to society. It has research facilities in California, Hawaii and the U.S.-affiliated Pacific Islands. For more information, visit http://www.
Stephanie Worley Firley | EurekAlert!
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
Pollen taxi for bacteria
18.07.2018 | Technische Universität München
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....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
18.07.2018 | Materials Sciences
18.07.2018 | Life Sciences
18.07.2018 | Health and Medicine