HOME >> BIOLOGY >> NEWS
Winning by a neck -- Giraffes avoid competing with shorter browsers

The giraffe's elongated neck has long been used in textbooks as an illustration of evolution by natural selection, but this common example has received very little experimental attention. In the January issue of the American Naturalist, researchers at the Mammal Research Institute in the Department of Zoology and Entomology at the University of Pretoria tested whether foraging competition with shorter herbivores could explain why giraffes feed mostly on leaves high in trees, despite being able to feed at lower levels as well.

"This [study] provides the first real experimental evidence that the long neck of the giraffe might have evolved as a consequence of competition, which provides support for a previously untested textbook example of natural selection," says Elissa Cameron (University of Pretoria), who coauthored the study with Johan du Toit (University of Pretoria and Utah State University).

Giraffes are well known for their unusual height, and they generally feed high in the tree canopy, above the height other herbivores can reach. Giraffes receive more leaves per bite by foraging high in the tree, but it's unclear whether this is caused by competition -- smaller browsers eating some of the leaves at lower heights -- or if more leaves grow at higher levels.

The researchers built low fences around trees in greater Kruger National Park to stop smaller browsers from eating leaves. After a complete growing season they found that the number of leaves on the fenced trees was roughly the same, revealing that small browsers are responsible for most of the foraging. Therefore, the researchers argue, it is competition from other herbivores, such as kudu, that appears to drive giraffes to eat leaves high in the trees.


'"/>

Contact: Patricia Morse
amnat@press.uchicago.edu
773-702-0446
University of Chicago Press Journals
22-Dec-2006


Page: 1

Related biology news :

1. Winning the oil endgame in America to be discussed at NJIT forum
2. Desertification: UN experts prescribe global policy overhaul to avoid looming mass migrations
3. The eyes have it! How box jellyfish avoid banging into things
4. Embryonic selection of sex avoids conceiving blind children
5. How to avoid a bat
6. Define precautionary principle to avoid clashes over biotechnology under World Trade rules
7. Elephants avoid costly mountaineering
8. How plants avoid feeling the burn
9. Heal thyself: Systems biology model reveals how cells avoid becoming cancerous
10. Female guppies risk their lives to avoid too much male attention
11. Altering genetic blueprint of receptors in brain could help stroke victims avoid brain damage

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:3/22/2016)... March 22, 2016 ... Sensors Market for Consumer Industry by Type (Image, ... Application (Communication & IT, Entertainment, Home Appliances, ... Forecast to 2022", published by MarketsandMarkets, the ... to reach USD 26.76 Billion by 2022, ...
(Date:3/15/2016)... --> --> ... Research "Digital Door Lock Systems Market - Global Industry Analysis, ... global digital door lock systems market in terms of revenue ... forecast to grow at a CAGR of 31.8% during the ... enterprises (MSMEs) across the world and high industrial activity driving ...
(Date:3/11/2016)... , March 11, 2016 ... market research report "Image Recognition Market by Technology (Pattern ... and Advertising), by Deployment Type (On-Premises and Cloud), by ... 2022", published by MarketsandMarkets, the global market is expected ... USD 29.98 Billion by 2020, at a CAGR of ...
Breaking Biology News(10 mins):
(Date:5/27/2016)... ... ... Weeks after hosting a carpal tunnel syndrome workshop with Dr. Oz on ... of the Fitzmaurice Hand Institute, has announced the addition of MRI diagnostic imaging services ... only 1 of about 3 currently available in the United States. Developed specifically for ...
(Date:5/27/2016)... NC (PRWEB) , ... May 27, 2016 , ... Doctors ... analyzing dozens of studies on the BRCA-1 associated protein (BAP1) gene and its link ... the website. Click here to read the full article now. , The ...
(Date:5/27/2016)... , May 27, 2016 At ... investors playing in this space know that volatility is what ... featured companies on ActiveWallSt.com: Synta Pharmaceuticals Corp. (NASDAQ: ... Lpath Inc. (NASDAQ: LPTN ), and Heat Biologics ... gain access to the technical alerts for these stocks at: ...
(Date:5/26/2016)... Jersey and READING, England ... Indegene ( http://www.indegene.com ), a leading global ... life science, pharmaceutical and healthcare organisations and TranScrip ... innovative scientific support throughout the product lifecycle, today ... the launch of IntraScience.      (Logo: ...
Breaking Biology Technology:
Cached News: