Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Killing only a few animals won't do any harm -- or will it?

25.07.2007
Using advanced mathematical modeling, researchers from Sweden and The Netherlands show in an article in the August issue of the American Naturalist that this statement is sometimes true.

Sometimes though, killing even a few individuals can have dramatic consequences, causing populations to fluctuate wildly. “The important question is: who gets killed" The effects of killing individuals crucially depend on the size of the victims,” says Tobias van Kooten, assistant professor at Umeå University in Sweden.

The regulation of populations is usually determined by the properties of one specific size class of individuals. In some species, this “crucial stage” consists of small individuals that can monopolize the available food, denying it to all other individuals.Alternatively, especially in fish populations, large individuals can limit the abundance of smaller individuals through cannibalism. It is when such a crucial size class is the target of mortality that unexpected things may happen.

Van Kooten and co-workers predict for example that in harvested cannibalistic fish populations, individuals may reach “giant” sizes, more than double the size of those in unharvested population. Indeed, such “giant cannibals” seem to occur frequently in heavily fished lakes. “Our results are directly applicable to conservation and management, since almost all human-induced mortality is size-selective,” van Kooten states. “Fishermen select gear to catch large fish, while deer hunters prefer the tender meat of calves.”

Unexpected effects of mortality have been reported before, but this systematic study, to be published in The American Naturalist, unravels the mechanisms behind the effects. Such “deep” understanding makes it possible to predict effects of size-dependent mortality for a wide range of species.

Patricia Morse | EurekAlert!
Further information:
http://www.uchicago.edu

More articles from Ecology, The Environment and Conservation:

nachricht Despite government claims, orangutan populations have not increased. Call for better monitoring
06.11.2018 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

nachricht Increasing frequency of ocean storms could alter kelp forest ecosystems
30.10.2018 | University of Virginia

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

Im Focus: Coping with errors in the quantum age

Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly

The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...

Im Focus: Nanorobots propel through the eye

Scientists developed specially coated nanometer-sized vehicles that can be actively moved through dense tissue like the vitreous of the eye. So far, the transport of nano-vehicles has only been demonstrated in model systems or biological fluids, but not in real tissue. The work was published in the journal Science Advances and constitutes one step further towards nanorobots becoming minimally-invasive tools for precisely delivering medicine to where it is needed.

Researchers of the “Micro, Nano and Molecular Systems” Lab at the Max Planck Institute for Intelligent Systems in Stuttgart, together with an international...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

In focus: Peptides, the “little brothers and sisters” of proteins

12.11.2018 | Life Sciences

Materials scientist creates fabric alternative to batteries for wearable devices

12.11.2018 | Materials Sciences

A two-atom quantum duet

12.11.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>