ABSTRACT The expansion of oil palm (Elaeis guineensis) cultivation has been recognised as a major threat to tropical biodiversity. Smallholdings, however, unlike large-scale conventional monoculture oil palm plantations, often practice polyculture which may resemble an agroforestry system. These private holdings provide more heterogeneous vegetation which may support greater a greater diversity of birds. This study compared species richness and abundance of birds detected perching in oil palm (both dead and living trees) and seven other planted crop species within oil palm smallholdings. Using transect line surveys, we recorded a total of 816 birds of 39 species from 20 families. Our results indicate that bird species richness and abundance differed significantly between oil palm and the other planted tree species. Non-oil palm trees cumulatively increased bird species richness and abundance. Although birds overall perched more frequently on living oil palm trees (probably reflecting relative abundance), other species including breadfruit, mango, papaya, banana, and coconut, as well as dead trees, were also used. By measuring effect size, we also found that both bird species richness and abundance rely on tree structure and type of tree species. These findings tentatively suggest that providing a larger diversity of tree species within intensively managed oil palm plantations may support a wider variety of local bird species compared to monocultures.

中文翻译：

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马来西亚油棕农林景观中与不同树种和结构相关的鸟类

摘要 油棕（Elaeis guineensis）种植的扩大已被认为是对热带生物多样性的主要威胁。然而，与传统的大规模单一种植油棕种植园不同，小农场通常采用可能类似于农林业系统的混养。这些私人财产提供了更多样化的植被，可以支持更多种类的鸟类。该研究比较了在油棕（死树和活树）和油棕小农场内其他七种种植作物物种中检测到的鸟类物种丰富度和丰度。通过样线调查，我们共记录了 20 个科 39 种 816 只鸟类。我们的结果表明，油棕和其他种植树种之间的鸟类物种丰富度和丰度存在显着差异。非油棕树累积增加了鸟类物种的丰富度和丰度。虽然鸟类总体上更频繁地栖息在活的油棕树上（可能反映了相对丰富的数量），但也使用了其他物种，包括面包果、芒果、木瓜、香蕉和椰子，以及枯树。通过测量效应大小，我们还发现鸟类物种丰富度和丰度都依赖于树结构和树种类型。这些发现初步表明，与单一栽培相比，在集约化管理的油棕种植园内提供更多种类的树种可能支持更多种类的当地鸟类。还使用了香蕉、椰子以及枯树。通过测量效应大小，我们还发现鸟类物种丰富度和丰度都依赖于树结构和树种类型。这些发现初步表明，与单一栽培相比，在集约化管理的油棕种植园内提供更多种类的树种可能支持更多种类的当地鸟类。还使用了香蕉、椰子以及枯树。通过测量效应大小，我们还发现鸟类物种丰富度和丰度都依赖于树结构和树种类型。这些发现初步表明，与单一栽培相比，在集约化管理的油棕种植园内提供更多种类的树种可能支持更多种类的当地鸟类。