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:
TAG: Winning neck Giraffes avoid competing with shorter browsers

(Date:4/15/2014)... CLEVELAND, Ohio (April 16, 2014)A new study from the ... vitamin D levels and menopause symptoms. The study was ... of The North American Menopause Society., The authors analyzed ... and a number of menopause symptoms, including hot flashes, ... women who participated in the calcium and vitamin D ...
(Date:4/15/2014)... in Greenbelt, Md., is home to hundreds of ... Goddard, some of the most cutting-edge Earth science ... that cutting-edge innovation has earned a Goddard scientist ... for Anthropology and Geography awards the Vega Medal ... shown excellence in the fields of physical geography, ...
(Date:4/15/2014)... Missouri researchers have previously shown that a genetic pre-disposition ... In a new study, Frank Booth, a professor in ... potential link between the genetic pre-disposition for high levels ... maturation occurs. , For his study, Booth selectively bred ... extreme laziness. Booth then put the rats in cages ...
Breaking Biology News(10 mins):Low Vitamin D may not be a culprit in menopause symptoms 2Goddard scientist receives Vega Medal from King of Sweden 2Genetic pre-disposition toward exercise and mental development may be linked 2
(Date:1/15/2014)... 2014 The Microcompetition with Foreign DNA ... disease. One of these latent viruses is the Epstein ... rheumatoid arthritis (RA). Rheumatoid arthritis (RA) is a chronic ... by the theory, a study found that RA patients ... (1). , What is Microcompetition? , Dr. Hanan ...
(Date:1/15/2014)... Sunnyvale, CA (PRWEB) January 15, 2014 ... of high throughput research solutions, today announced that ... companies, has received delivery of Freeslate’s CM ... form screening. , Lupin, headquartered in Mumbai, ... quality, affordable generic and branded formulations and Active ...
(Date:1/14/2014)... (PRWEB) January 14, 2014 Date: Friday, ... p.m. , Location: Warrington Country Club, 1360 Almshouse Road, ... Foundation, the only national nonprofit organization solely dedicated to ... quality of life for those affected worldwide, will host ... Warrington Country Club in Warrington, Pa. , Each ...
(Date:1/14/2014)... , Jan. 14, 2014  3D Communications, a leading provider ... major scientific, regulatory, business, and media events in ... , today announced its former associate Virginia Cox , ... office. Virginia Cox re-joins ... Commissioner for the Office of External Affairs at the U.S. ...
Breaking Biology Technology:Study: Rheumatoid Arthritis (RA) Patients Have EBV; The CBCD Says this is Consistent with Microcompetition 2Study: Rheumatoid Arthritis (RA) Patients Have EBV; The CBCD Says this is Consistent with Microcompetition 3Lupin Selects Freeslate’s CM Protégé PharmD System to Accelerate Polymorph Screening for Drug Development 2Lupin Selects Freeslate’s CM Protégé PharmD System to Accelerate Polymorph Screening for Drug Development 3Hepatitis B Foundation to Host Annual Crystal Ball Gala 2Former FDA Associate Commissioner Returns To 3D Communications 2
Cached News: