当前位置: X-MOL 学术Biol. Conserv. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Human- and risk-mediated browsing pressure by sympatric antelope in an African savanna
Biological Conservation ( IF 5.9 ) Pub Date : 2019-04-01 , DOI: 10.1016/j.biocon.2019.01.028
Tobias O. Otieno , Jacob R. Goheen , Paul W. Webala , Albert Mwangi , Isaac M. Osuga , Adam T. Ford

Abstract Human activity shapes landscape heterogeneity, which can influence where and how species interact. In African savannas, human-mediated changes to woody cover affect perceptions of risk and foraging decisions by large herbivores. Through cafeteria-style feeding trials, we presented two common, browsing ungulates (Guenther's dik-dik [Madoqua guentheri] and impala [Aepyceros melampus]) with branches from four tree species that varied in their relative investment in mechanical and chemical defenses. We conducted trials in habitats that were perceived as risky to either dik-dik (i.e., open habitat) or impala (i.e., bushland habitat). We found that dik-dik preferred to eat thorny trees low in tannin content within bushland habitats, while the larger-bodied impala preferred tannin-rich but thorn-less branches within open habitats. Risk-induced habitat use homogenized browsing pressure in the lower canopy, but increased heterogeneity in browsing pressure in the upper canopy. In addition, plant defenses neutralized the effects of risk, and foraging height on browsing pressure. Our results demonstrate how foraging experiments—typically the basis for field studies on species coexistence—can be extended to make inferences about consumer-resource dynamics in human-modified landscapes.

中文翻译:

非洲大草原中同域羚羊的人类和风险介导的浏览压力

摘要 人类活动塑造了景观异质性,这会影响物种相互作用的地点和方式。在非洲稀树草原,人为介导的木质覆盖变化会影响大型食草动物对风险的感知和觅食决定。通过自助餐厅式喂养试验,我们展示了两种常见的有蹄类动物(Guenther's dik-dik [Madoqua guentheri] 和黑斑羚 [Aepyceros melampus]),其分支来自四种树种,它们在机械和化学防御方面的相对投资各不相同。我们在被认为对 dik-dik(即开放栖息地)或黑斑羚(即丛林栖息地)有风险的栖息地进行了试验。我们发现 dik-dik 更喜欢在丛林栖息地内吃单宁含量低的带刺树,而体型较大的黑斑羚更喜欢在开阔的栖息地内富含单宁但无刺的树枝。风险诱导的栖息地在下部树冠中使用均质的浏览压力,但在上部树冠中使用浏览压力的异质性增加。此外,植物防御中和了风险和觅食高度对浏览压力的影响。我们的结果证明了觅食实验——通常是物种共存实地研究的基础——可以扩展到对人类改造景观中的消费者资源动态进行推断。
更新日期:2019-04-01
down
wechat
bug