Effects of food quality, diet preference and water on patch use by Nubian ibex

• Published in: Oikos Vol. 112; no. 3; pp. 547 - 554
• Main Authors: Hochman, Valeria, P. Kotler, Burt
• Format: Journal Article
• Language: English
• Published: Copenhagen Munksgaard International Publishers 01-03-2006; Blackwell Publishers; Blackwell; Blackwell Publishing Ltd
• Subjects: Animal and plant ecology; Animal behavior; Animal feeding behavior; Animal, plant and microbial ecology; Biological and medical sciences; Cliffs; Deserts; Diet; Ecology; Food; Food availability; Food security; Foraging; Fundamental and applied biological sciences. Psychology; General aspects; Habitats; Mammalia; Predation; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Water; Water resources; Negev Desert; Vertebrata; Feeding behavior; Mammalia; Diet; Water use; Artiodactyla; Feeding preference; Ungulata; Feeding
• ISSN: 0030-1299; 1600-0706
• DOI: 10.1111/j.0030-1299.2006.14214.x

Measuring patch use of a forager can reveal not only its cost and benefits from foraging, but also the importance of environmental factors and the significance of energy, nutrients and predation risk to its fitness. In order to assess the effects of various variables that may affect the foraging behavior of free-ranging Nubian ibex in the Negev Desert, Israel, giving-up densities (GUD) in artificial food patches were measured following Kotler et al. In particular, we tested the effects of food quality and water availability on Nubian ibex foraging behavior. To do so, we (1) tested whether the tannic acid content of food affected diet preferences, (2) assayed their diet selection strategy, (3) tested if the foraging decisions of the Nubian ibex were affected by the availability of water and (4) determined the nutritional relationship between food resources and water. Nubian ibex had lower GUDs and used resources patches more intensively where water was available, the food quality was higher and the location was closer to the escape terrain. Nubian ibex showed an expanding specialist diet selection when exploiting resource patches with a mix of items that differ in quality. Overall, food and water were complementary resources for Nubian ibex, and tannins reduced food quality. These factors help to determine patch foraging behavior decisions in Nubian ibex and contribute to habitat quality.