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:8/27/2014)... of studies have shown that excessive iron ... Parkinson,s disease. Previous studies from Chunyan Guo ... China have shown that baicalin prevented iron ... metal transporter 1 expression, and increased ferroportin ... rotenone-induced Parkinson,s disease rats. However, the relationship ...
(Date:8/27/2014)... has shown that piglets can be weaned later with ... outcome of the study at the University,s Roseworthy campus, ... is an important finding for pig producers. It allows ... production. , "Sows don,t usually start their oestrous cycles ... piglets have been weaned," says Ms Alice Weaver, PhD ...
(Date:8/27/2014)... is a dreaded bacterium that can be found ... few weeks, 28 persons in Denmark have been infected ... supermarkets. 13 have died. , The bacterium is notoriously ... ability to adapt to changes in its surroundings, says ... with colleagues from the Department of Biochemistry and Molecular ...
Breaking Biology News(10 mins):Piglet weaning age no bar to litter frequency 2Researchers discover why Listeria bacterium is so hard to fight 2Researchers discover why Listeria bacterium is so hard to fight 3
(Date:8/26/2014)... An analysis by Replikins, Ltd. of Pubmed data of ... Pubmed, has revealed extensive conservation and sharing of specific ... of specific Replikin gene structures has permitted the formulation ... for the H5N1 influenza vaccine and the Taura Syndrome ... be effective (1,2). This Dengue vaccine ...
(Date:8/26/2014)... 2014   Lycera Corp ., a biopharmaceutical ... to treat autoimmune disease and cancer based on ... appointment of Harinder Singh , Ph.D., as ... Singh will lead the board,s efforts to provide ... research programs and pipeline of therapies targeting unmet ...
(Date:8/26/2014)... San Francisco, CA (PRWEB) August 26, 2014 ... to reach USD 8,020.1 million by 2020, according to ... demand for personalized medicine and theranostics, and the subsequent ... be key factors driving market growth over the next ... population and chronic diseases such as cancer, coupled with ...
(Date:8/26/2014)... 26, 2014 Genedata, a leading ... and life science research, today announced the ... be held in Asia, Europe, and North America ... companies and leading research organizations will gather for ... case studies, and upcoming challenges in all areas ...
Breaking Biology Technology:Lycera Appoints Harinder Singh, Ph.D., as Chair of Scientific Advisory Board 2Lycera Appoints Harinder Singh, Ph.D., as Chair of Scientific Advisory Board 3World Molecular Diagnostics Market Is Expected To Grow To $8,020.1 Million From 2014 To 2020: Grand View Research, Inc 2World Molecular Diagnostics Market Is Expected To Grow To $8,020.1 Million From 2014 To 2020: Grand View Research, Inc 3World Molecular Diagnostics Market Is Expected To Grow To $8,020.1 Million From 2014 To 2020: Grand View Research, Inc 4World Molecular Diagnostics Market Is Expected To Grow To $8,020.1 Million From 2014 To 2020: Grand View Research, Inc 5World Molecular Diagnostics Market Is Expected To Grow To $8,020.1 Million From 2014 To 2020: Grand View Research, Inc 6Thought Leaders to Explore Innovations in SPR & Combination Screening at Genedata Screener User Group Meetings 2Thought Leaders to Explore Innovations in SPR & Combination Screening at Genedata Screener User Group Meetings 3
Cached News: