Large herbivores in rangelands

Ammonia in the large intestine of herbivores.

I. The object was to investigate the importance of urea as a source of ammonia in the large intestine of herbivores. Urea was present in small intestinal contents of slaughtered horses in concentrations similar to those in blood but, in the small intestine of slaughtered sheep, the urea was less than in blood. 2. There was little ammonia in small intestinal contents of slaughtered horses but co...

Resource-ratio theory applied to large herbivores.

The theoretical description of exploitation competition, known as resource competition theory (RCT) or resource-ratio theory, has been tested in terrestrial plant communities and microorganisms in laboratory cultures. Applications in animal ecology have been rare, although the theory itself is generic. A major difficulty is that the description of resources in RCT is fundamentally different fro...

How large herbivores subsidize aquatic food webs in African savannas.

Mass migration—the periodic, synchronized movement of large numbers of animals from one place to another— is an important part of the life cycle of many species. Such migrations are variously a means of avoiding climatic stress, escaping food and water scarcity, and satiating predators (thereby reducing individuals’ risk of being eaten). They are among the most spectacular of natural phenomena,...

Rangelands in Arid Ecosystem

Loss of Large Herbivores from an African Savanna

www.sciencemag.org (this information is current as of January 12, 2008 ): The following resources related to this article are available online at http://www.sciencemag.org/cgi/content/full/319/5860/192 version of this article at: including high-resolution figures, can be found in the online Updated information and services, http://www.sciencemag.org/cgi/content/full/319/5860/192/DC1 can be foun...