Featured Research

from universities, journals, and other organizations

Researchers Establish Formula For Predicting Predator-Prey Populations

Date:
November 17, 2000
Source:
North Carolina State University
Summary:
The complicated population interactions of predator and prey species have long intrigued scientists, who have developed mathematical models that predict how those populations interact. They've had difficulty, however, demonstrating that such predictions reflect reality for species more complex than single-celled organisms. Now, a team of scientists from Cornell University and North Carolina State University has done exactly that.

The complicated population interactions of predator and prey species have long intrigued scientists, who have developed mathematical models that predict how those populations interact. They've had difficulty, however, demonstrating that such predictions reflect reality for species more complex than single-celled organisms.

Now, a team of scientists from Cornell University and North Carolina State University has done exactly that. Their laboratory research -- on the population interactions of tiny multicellular planktonic rotifers and the single-celled green algae on which they feed -- is highlighted in the Nov. 16 issue of the journal Science.

Their research is the first to use long-duration experiments of multiple interacting species to verify a mathematical population model. Their conclusion: a few straightforward rules can govern predator-prey population dynamics for species more complex than single-celled bacteria and protists.

"We combine theoretical and empirical approaches to demonstrate that a few simple mechanistic processes underlie complex multispecies dynamics and that a correspondingly simple model is a sound tool for investigating community properties," the researchers write in the Science article.

The co-authors on the Science paper are Dr. Gregor F. Fussmann, a post-doctoral associate at Cornell University; Dr. Stephen P. Ellner, formerly a professor of biomathematics at NC State and now at Cornell; Kyle W. Shertzer, a biomathematics doctoral candidate at NC State; and Dr. Nelson G. Hairston Jr., Frank H.T. Rhodes Professor of Environmental Science at Cornell.

Their research indicates that simple mathematical models may be useful in helping to predict the population dynamics of a variety of multicellular organisms in the natural world, such as during outbreaks of agricultural pest species. And it could serve as a launching point for studies on the possible co-evolution of predator and prey species, and on the possibility that some organisms have evolved in a way that reduces the likelihood of complex population dynamics.

The model developed by the researchers is a set of four equations designed to describe the dynamics of the system. They tested the model by running experiments using a water-containing apparatus, in which they placed the predator rotifers -- Brachionus calyciflorus -- and the prey algae -- Chlorella vulgaris. During 18 experimental trials, they varied the concentration of nitrogen pumped into the system and the dilution rate of the water in the system. The nitrogen concentration determined the birth rate of the algae, which, in turn, determined the rotifers' birth rate.

Those trials yielded results expected by the model, varying according to the nitrogen concentration input and the rate at which the water was diluted. At low nitrogen levels, the two species coexisted at an equilibrium or in cycles. At intermediate dilution rates, the populations oscillated, while they remained at equilibrium at high and low dilution levels.

Shertzer, the NC State biomathematics doctoral candidate, said the research indicates that internal population limitations -- such as predator-prey interactions -- can drive population cycles without any forcing from external limitations such as environmental conditions. And, he explains, the research team has demonstrated that researchers don't need to know everything about an environmental system to predict its population dynamics.

"It is a really simple model that's able to catch the important mechanisms of the system necessary to describe the system," he said. "This shows that you don't necessarily need to track every detail to make accurate predictions." Shertzer continues to work with Dr. Stephen Ellner to refine the model.


Story Source:

The above story is based on materials provided by North Carolina State University. Note: Materials may be edited for content and length.


Cite This Page:

North Carolina State University. "Researchers Establish Formula For Predicting Predator-Prey Populations." ScienceDaily. ScienceDaily, 17 November 2000. <www.sciencedaily.com/releases/2000/11/001117071629.htm>.
North Carolina State University. (2000, November 17). Researchers Establish Formula For Predicting Predator-Prey Populations. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2000/11/001117071629.htm
North Carolina State University. "Researchers Establish Formula For Predicting Predator-Prey Populations." ScienceDaily. www.sciencedaily.com/releases/2000/11/001117071629.htm (accessed September 22, 2014).

Share This



More Plants & Animals News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Cat Lovers Flock to Los Angeles

Cat Lovers Flock to Los Angeles

AFP (Sep. 22, 2014) The best funny internet cat videos are honoured at LA's Feline Film Festival. Duration: 00:56 Video provided by AFP
Powered by NewsLook.com
Raw: San Diego Zoo Welcomes Cheetah Cubs

Raw: San Diego Zoo Welcomes Cheetah Cubs

AP (Sep. 20, 2014) The San Diego Zoo has welcomed two Cheetah cubs to its Safari Park. The nearly three-week-old female cubs are being hand fed and are receiving around the clock care. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
Top 3 Outrageous Animal Stories Of The Week

Top 3 Outrageous Animal Stories Of The Week

Newsy (Sep. 19, 2014) This week's animal stories include a goldfish having surgery, a pizza chain giving out pets, and a tiger found on the side of the road. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins