Navigation Links
Biologist Belovsky's paper offers new insights into predator/prey relationships

For those old enough to remember Mutual of Omaha's "Wild Kingdom" television series, the dynamics of predator-prey relationships seemed clear enough: predators thinned out prey populations, which enabled a smaller, but stronger, population to survive and reproduce.

However, a new paper by University of Notre Dame biologist Gary Belovsky appearing in the prestigious journal Ecology Letters suggests that predator-prey relationships are much more complex than originally thought.

The paper arose out of pioneering studies Belovsky, who also is director of the Notre Dame Environmental Research Center (UNDERC), has been conducting on grasshopper populations since 1978 at Montana's National Bison Range, now a location for one of UNDERC's national undergraduate programs.

Belovsky conducted an experiment to examine how behavioral responses of grasshoppers to avian predators affected grasshopper survival and reproduction at different grasshopper population densities. A series of cages containing grasshoppers were enclosed within a tent constructed of aviary netting, creating a "no threat" area because its design prevented birds from approaching the cages and "scarring" the grasshoppers. A second set of cages provided a "threat" area because it was not enclosed in a tent, which allowed birds to feed around the cages, perch on top consuming grasshoppers caught outside the cages and "scare" the grasshoppers inside the cages.

The research demonstrated that grasshopper behavior changed with the threat of predators, reducing grasshopper feeding, and this was apparent at all grasshopper densities. The behavioral changes with the threat of predation increased survival at low grasshopper densities, as reduced feeding made food available to more individuals, while the changes decreased survival at higher densities, as severe food shortages were made worse by reduced feeding. However, the behavioral changes decreased per capita reproduction over all grasshopper population densities, as grasshoppers traded off survival and reproduction as competition among the grasshoppers increased with greater population densities.

This type of variable response is generally overlooked when prey behavioral changes with predation are considered in how predation affects prey populations," Belovsky said. "Resource availability may need to be considered when assessing how prey behavioral changes with predation threat affect population and food web dynamics."

Belovsky also notes that the new paper reinforces the importance of his western prairie research, which is now the longest running experimental study at a site examining what controls grasshopper populations. Although it isn't feasible to conduct a population study like this with populations of larger animals, such as elk and wolves in far-flung areas such as Alaska, the more easily observable field work with grasshoppers and birds offers important predator-prey insights that can be applied to these types of populations.


Contact: Gary Belovsky
University of Notre Dame

Related biology news :

1. Caltech biologists spy on the secret inner life of a cell
2. Biologists, educators recognize excellence in evolution education
3. Caltech geobiologists discover unique magnetic death star fossil
4. Biologists discover gene behind plant sex mystery
5. NYU biologist Bonneau named among 20 "visionary" scientists under 40 by Discover magazine
6. Queens University biologists find new environmental threat in North American lakes
7. Biologists learn structure, mechanism of powerful molecular motor in virus
8. Biologists discover link between CGG repeats in DNA and neurological disorders
9. Biologist enhances use of bioinformatic tools and achieves precision in genetic annotation
10. Biologists solve mystery of black wolves
11. Biologist receives the 2008 AAAS Public Understanding of Science and Technology Award
Post Your Comments:
(Date:11/9/2015)... JOSE, Calif. , Nov. 9, 2015  Synaptics ... human interface solutions, today announced broader entry into the ... vehicle-specific solutions that match the pace of consumer electronics ... and biometric sensors are ideal for the automotive industry ... vehicle. Europe , ...
(Date:10/29/2015)... RESTON, Va. , Oct. 29, 2015 ... announced today that it has released a new version ... Daon customers in North America ... gains. IdentityX v4.0 also includes a FIDO UAF ... customers are already preparing to activate FIDO features. These ...
(Date:10/27/2015)... , Oct. 27, 2015 In the present ... of concern for various industry verticals such as banking, ... to the growing demand for secure & simplified access ... ,sectors, such as hacking of bank accounts, misuse of ... equipment such as PC,s, laptops, and smartphones are expected ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... ... 25, 2015 , ... Jessica Richman and Zachary Apte, founders ... initial angel funding process. Now, they are paying it forward to other microbiome ... investments in the microbiome space. In this, they join other successful entrepreneurs-turned-angels ...
(Date:11/24/2015)... 2015 Halozyme Therapeutics, Inc. (NASDAQ: HALO ) will ... New York on Wednesday, December 2 at 9:30 a.m. ... and CEO, will provide a corporate overview. th ... at 1:00 p.m. ET/10:00 a.m. PT . Jim Mazzola ... a corporate overview. --> th Annual Oppenheimer Healthcare ...
(Date:11/24/2015)... CITY , Nov. 24, 2015 /PRNewswire/ - Aeterna ... request of IIROC on behalf of the Toronto Stock ... news release there are no corporate developments that would ... --> --> About ... . --> Aeterna Zentaris is ...
(Date:11/24/2015)... ... ... The Academy of Model Aeronautics (AMA), led by its Executive Council, has officially ... to represent the First–Person View (FPV) racing community. , FPV racing has exploded in ... racing and several new model aviation pilots have joined the community because of their ...
Breaking Biology Technology: