Selva Nuria, Fortuna Miguel A
Institute of Nature Conservation, Polish Academy of Sciences, Mickiewicza 33, 31-120 Kraków, Poland.
Proc Biol Sci. 2007 Apr 22;274(1613):1101-8. doi: 10.1098/rspb.2006.0232.
Scavenging is a widespread phenomenon in vertebrate communities which has rarely been accounted for, in spite of playing an essential role in food webs by enhancing nutrient recycling and community stability. Most studies on scavenger assemblages have often presented an oversimplified view of carrion foraging. Here, we applied for the first time the concept of nestedness to the study of a species-rich scavenger community in a forest ecosystem (Białowieza Primeval Forest, Poland) following a network approach. By analysing one of the most complete datasets existing up to now in a pristine environment, we have shown that the community of facultative scavengers is not randomly assembled but highly nested. A nested pattern means that species-poor carcasses support a subset of the scavenger assemblage occurring at progressively species-rich carcasses. This result contradicts the conventional view of facultative scavenging as random and opportunistic and supports recent findings in scavenging ecology. It also suggests that factors other than competition play a major role in determining community structure. Nested patterns in scavenger communities appear to be promoted by the high diversity in carrion resources and consumers, the differential predictability of the ungulate carcass types and stressful environmental conditions.
食腐行为是脊椎动物群落中一种普遍存在的现象，尽管它通过促进营养物质循环和群落稳定性在食物网中发挥着重要作用，但却很少得到关注。大多数关于食腐动物组合的研究往往对腐肉觅食给出了过于简化的观点。在这里，我们首次将嵌套性概念应用于森林生态系统（波兰比亚沃维耶扎原始森林）中一个物种丰富的食腐动物群落的研究，采用网络方法。通过分析目前在原始环境中最完整的数据集之一，我们发现兼性食腐动物群落并非随机组合，而是高度嵌套的。嵌套模式意味着物种较少的尸体所吸引的食腐动物组合是物种逐渐丰富的尸体所吸引的食腐动物组合的一个子集。这一结果与传统观点中兼性食腐行为是随机和机会主义的观点相矛盾，并支持了食腐生态学的最新发现。这也表明，除竞争之外的其他因素在决定群落结构方面起着主要作用。食腐动物群落中的嵌套模式似乎是由腐肉资源和消费者的高度多样性、有蹄类动物尸体类型的不同可预测性以及压力环境条件所促进的。
