Fine-tuning the fruit-tracking hypothesis: spatiotemporal links between fruit availability and fruit consumption by birds in Andean mountain forests.
Fine-tuning the fruit-tracking hypothesis: spatiotemporal links between fruit availability and fruit consumption by birds in Andean mountain forests.
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微调水果追踪假说：安第斯山森林中水果供应与鸟类水果消费之间的时空联系。
DOI：
10.1111/j.1365-2656.2012.02011.x
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Josefina Haedo
中科院分区：
文献类型：
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作者：
P. G. Blendinger;R. A. Ruggera;M. G. Núñez Montellano;L. Macchi;P. Zelaya;M. Alvarez;E. Martín;Oriana Osinaga Acosta;R. Sanchez;Josefina Haedo
1. 水果追踪假说预测了食果鸟类的丰度变化与其肉质水果资源的丰度之间的时空联系。 2. 虽然已经探索了植物-食果动物相互作用的空间尺度，以了解观察到的和预期的水果-食果动物模式之间的不匹配，但尚未评估测量水果和食果动物丰度而不是水果可用性和水果消费的后果等方法学问题。 3.在这里，我们探讨了是否可以通过相互作用强度的近似测量来更准确地捕获预测的水果-食果动物时空联系。我们在安第斯亚热带森林中使用了 6 公顷的网格地块来研究 (i) 水果和食果鸟类丰度之间的联系； (ii) 水果供应情况和水果消费频率； (iii) 食果动物丰度和食果频率之间的协变。我们使用两年期间每两个月收集的数据评估了整个食果动物组合和四个最重要物种的这些联系。 4. 肉质果实的可用性和丰度随时间变化很大，并且呈斑块状分布，果实数量不同。水果的可用性和丰度也随着整个研究地块的空间梯度而变化。我们发现，随着时间的推移，整个食果鸟类群落对水果供应量有强烈的反应，而在局部范围内，与空间的关系则较弱。主要食果动物物种对果实丰度变化的反应差异很大，因此组合水平的反应不能被视为每个物种个体反应的总和。我们的研究结果表明，果食性食虫鸟类的水果追踪在很大程度上可以通过物种对水果和替代资源可用性变化的特定反应来解释。 5. 与我们的预测一致，对相互作用强度的更准确测量比传统测量更好地描述了水果与食果动物的关系。此外，我们表明，食果动物丰度、水果消费频率和水果可用性之间的协变必须包含在水果跟踪假设框架中，以证明（或拒绝）时空水果跟踪。我们建议，对水果中营养物质和能量可用性的估计可能是了解推动水果追踪的觅食决策的力量的新领域。
1. The fruit-tracking hypothesis predicts spatiotemporal links between changes in the abundance of fruit-eating birds and the abundance of their fleshy-fruit resources. 2. While the spatial scale of plant-frugivore interactions has been explored to understand mismatches between observed and expected fruit-frugivore patterns, methodological issues such as the consequences of measuring fruit and frugivore abundance rather than fruit availability and fruit consumption have not been evaluated. 3. Here, we explored whether predicted fruit-frugivore spatiotemporal links can be captured with higher accuracy by proximate measurements of interaction strength. We used a 6-ha grided plot in an Andean subtropical forest to study the link between (i) fruit and fruit-eating bird abundances; (ii) fruit availability and frequency of fruit consumption; and (iii) covariation between frugivore abundance and frequency of frugivory. We evaluated these links for the entire frugivore assemblage and for the four most important species using data gathered bimonthly along a 2-year period. 4. Fleshy-fruit availability and abundance varied sharply temporally and were patchily distributed in mosaics that differed in fruit quantity. Fruit availability and abundance also varied along spatial gradients extended over the whole study plot. We found a strong response of the entire frugivorous bird assemblage to fruit availability over time, and a weakly significant relationship over space at the local scale. The main frugivore species widely differed in their responses to changes in fruit abundance in such a way that response at the assemblage level cannot be seen as the sum of individual responses of each species. Our results suggest that fruit tracking in frugivorous-insectivorous birds may be largely explained by species-specific responses to changes in the availability of fruits and alternative resources. 5. In agreement with our prediction, more accurate measurements of interaction strength described fruit-frugivore relationships better than traditional measurements. Moreover, we show that covariation between frugivore abundance, frequency of fruit consumption and fruit availability must be included in the fruit-tracking hypothesis framework to demonstrate (or reject) spatiotemporal fruit tracking. We propose that estimation of nutrient and energy availability in fruits could be a new frontier to understanding the forces driving foraging decisions that lead to fruit tracking.