Featured Research

from universities, journals, and other organizations

Human Taste For Rarity Spells Disaster For Endangered Species

Date:
November 28, 2006
Source:
Public Library of Science
Summary:
A model shows how the value that humans place on rarity fuels disproportionate exploitation of rare species, rendering them even rarer and thus more desirable, ultimately leading them into a vortex of extinction.

By placing an exaggerated value on rarity, humans can drive rare species into a vortex of extinction, through a process called the anthropogenic Allee effect.
Credit: Image Maria Angulo / Courtesy of PLoS Biology

The shady pursuit of endangered bird eggs made international headlines in May 2006 when Colin Watson, widely considered Britain's most notorious illegal egg collector, died after falling from a 12-meter tree, allegedly while hunting a rare egg. The Royal Society for the Protection of Birds estimates that up to 30 of Britain's most vulnerable species are targeted by collectors. Classical economics theory predicts that such exploitation is unlikely to extinguish a species because the cost of finding the last individuals would outweigh the benefits. But a new theoretical study in PLoS Biology shows that adding human behavior to the equation--specifically, the human penchant for rarity--reveals an unexpected mechanism of exploitation, with alarming implications for species survival. Franck Courchamp, Elena Angulo, and their colleagues incorporated the assumption that rarity increases a species' value into a classic model of resource exploitation used to manage fisheries. Prizing rarity, they found, triggers a positive feedback loop between exploitation and rarity that drives a species into an extinction vortex.

This phenomenon, the authors explain, resembles an ecological process called the Allee effect, in which individuals of many plant and animal species suffer reduced fitness at low population densities, which increases their extinction risk. The authors' model now shows that humans can trigger an "anthropogenic Allee effect" in rare species through a paradox of value. When rarity acquires value, prices for scarce species can skyrocket, even though continued exploitation will precipitate extinction. And as long as someone will pay any price for the rarest of the rare, market price will cover (and exceed) the cost of harvesting the last giant parrot, tegu lizard, or lady's slipper orchid on Earth.

The authors describe multiple human activities that could precipitate the anthropogenic Allee effect. Hobby collections of the sort Watson allegedly gave his life for top their list. Overhunting for food and feathers pushed the great auk (Pinguinus impennis)--a flightless, now-extinct bird that laid only one egg a year--to the brink of extinction. But it was likely scientists and museum collectors anxious to nab an increasingly rare specimen, the authors suggest, that finished the bird off. And trophy hunting collectors have placed increasing pressure on rare species as their focus has shifted from killing the most dangerous animals to killing the rarest. The pursuit of social status and health can also trigger the anthropogenic Allee effect, as many rare species are coveted as luxury items--whether for handbags, exotic cuisine, or dining room furniture--or traditional medicines. The exotic pet trade continues to threaten orangutans, monkeys, reptiles, birds, and wild cats, as well as a wide variety of arachnids, insects, and fish. And it appears that pet trade dealers read the scientific literature for clues to the next hot species: immediately after an article recognized the small Indonesian turtle (Chelodina mccordi) and Chinese gecko (Goniurosaurus luii) as rarities, their prices soared. The turtle is now nearly extinct and the gecko can no longer be found in its southeastern China niche. Even well-intentioned activities like ecotourism may destabilize threatened populations.

How to conserve biodiversity when simply declaring a species endangered catalyzes its exploitation? Since many collectors, pet owners, and ecotourists actually care about biodiversity, the authors hope that education may go a long way toward curbing these human activities. Education could even mitigate the damage of trophy hunting and luxury consumption if society stigmatized activities responsible for driving a species to extinction and people could no longer take pride in displaying such "treasures." But for those who prize rarity above all else, only strengthened regulations and interventions will decrease the probability of a coveted species' extinction. And until those protections are firmly in place and enforceable, biologists may do well to think twice before reporting a species' decline.

Citation: Courchamp F, Angulo E, Rivalan P, Hall RJ, Signoret L, et al. (2006) Rarity value and species extinction: The anthropogenic Allee effect. PLoS Biol 4(12): e415. DOI: 10.1371/journal.pbio.0040415.


Story Source:

The above story is based on materials provided by Public Library of Science. Note: Materials may be edited for content and length.


Cite This Page:

Public Library of Science. "Human Taste For Rarity Spells Disaster For Endangered Species." ScienceDaily. ScienceDaily, 28 November 2006. <www.sciencedaily.com/releases/2006/11/061128084509.htm>.
Public Library of Science. (2006, November 28). Human Taste For Rarity Spells Disaster For Endangered Species. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2006/11/061128084509.htm
Public Library of Science. "Human Taste For Rarity Spells Disaster For Endangered Species." ScienceDaily. www.sciencedaily.com/releases/2006/11/061128084509.htm (accessed July 30, 2014).

Share This




More Plants & Animals News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Raw: Otters Enjoy Water Slides at Japan Zoo

Raw: Otters Enjoy Water Slides at Japan Zoo

AP (July 30, 2014) River otters were hitting the water slides to beat the summer heatwave on Wednesday at Ichikawa City's Zoological and Botanical Garden. (July 30) Video provided by AP
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