High plant diversity stimulates foraging motivation in grazing herbivores

作者：Feng, Chao; Ding, Shiwen; Zhang, Tianyuan; Li, Zhiqiang; Wang, Deli; Wang, Ling^*; Liu, Chen; Sun, Jinyan; Peng, Fugang

来源：Basic and Applied Ecology, 2016, 17(1): 43-51.

DOI：10.1016/j.baae.2015.09.004

• Food intake
• Grazing sheep
• Foraging behavior
• Plant diversity

One of the main challenges of studying grazing ecology is to predict food intake of herbivores. Plant species diversity may have important consequences for regulation of food intake by generalist herbivores. To reveal the regulation processes underlying food intake affected by plant species richness, we investigated sheep foraging during a 2-h foraging period (subdivided into four 30-min intervals) in response to altered plant species richness (2, 4, 6, and 8 species) using an indoor cafeteria trial. Our results showed that high plant diversity significantly improved a sheep's intake during each of the lime intervals, and the extent of improvement for intake gradually strengthened as foraging proceeded. Furthermore, we found that dynamics of food intake was modified as plant species richness increased. At lower plant diversity, intake of sheep was highest at the beginning and then decreased continuously as satiation proceeded. But this decreasing trend gradually slowed as the available plant diversity increased, and sheep even maintained high and constant intake during all intervals for the 6 and 8 species level. Fasting is generally thought to be an important endogenous factor affecting herbivore foraging motivation, and effects of fasting decreased as satiation proceeded. Our study indicated that diet diversity could be an important exogenous factor, and the diversity effects significantly increased with time. The complementary effects of endogenous and exogenous factors resulted in high herbivore intake during the entire 2-h grazing bouts under conditions of high plant diversity. We concluded that diet diversity can greatly increase foraging motivation of sheep, and improving foraging motivation, especially at the later phase of the meal, seems to be a key factor for stimulating food intake by the herbivore. Our study also indicates that conserving grassland plant diversity is critically beneficial not only to plant productivity, but also to animal productivity.

• 出版日期2016-2
• 单位黑龙江省农业科学院; 东北师范大学