Scientists often measure the effects of temperature on insects to predict how climate change will affect their distribution and abundance, but a Dartmouth study shows for the first time that insects' fear of their predators, in addition to temperature, ultimately limits how fast they grow.
"In other words, it's less about temperature and more about the overall environmental conditions that shape the growth, survival and distribution of insects." says the study's lead author Lauren Culler, an Arctic postdoctoral researcher at Dartmouth.
A new Dartmouth study shows for the first time that damselflies and other insects' fear of their predators, in addition to temperature, ultimately limits how fast they grow.
Credit: Philip Cohen
The study appears in the journal Oecologia. A PDF is available on request.
Animals live in a constantly changing physical and biological environment, and the fear of being eaten can drastically alter their behavior, physiology, growth and population dynamics. That fear, known as the "flight-or-fight" response, can prompt physiological responses that stunt their growth and reproductive capability, either because they spend less time foraging for food and more time hiding or because they produce anti-predator defenses that can be energetically costly.
Previous studies have shown that warming temperatures make insects eat more and grow faster. The Dartmouth study looked at how fear, which typically lowers food consumption and growth rate, affects an insects' response to warming temperatures.
They brought damselflies into the lab and measured how much they ate and grew at different temperatures and how that changed when a fish predator was nearby. They used an experimental setup in which a damselfly was floated in a glass vial and exposed visually and chemically to a fish predator.
The results showed that in the absence of fear, the damselflies ate more food and grew faster as the temperature increased. Surprisingly, however, when a fish predator was looming, the damselflies ate about the same amount of food but grew much more slowly. The researchers aren't sure what happens to the food that doesn't go into growth, but they think it gets lost in the anti-predator response, possibly to production of stress proteins.
"Studies that aim to predict the consequences of climate change on insect populations should consider additional factors that may ultimately limit growth and survival, such as the risk of being eaten by a predator," Culler says.
Postdoctoral researcher Lauren Culler is available to comment at email@example.com
Broadcast studios: Dartmouth has TV and radio studios available for interviews. For more information, visit: http://www.dartmouth.edu/~opa/radio-tv-studios/
John Cramer | Eurek Alert!
22.02.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau
Separate brain systems cooperate during learning, study finds
22.02.2018 | Brown University
Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
22.02.2018 | Life Sciences
22.02.2018 | Physics and Astronomy
22.02.2018 | Earth Sciences