Seed husking time and maximal bite force in finches
Seed husking time and maximal bite force in finches
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DOI：
10.1242/jeb.02379
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发表时间：
2006-09
影响因子：
2.8
通讯作者：
M. A. A. V. D. Meij-M.-A.-A.-V.-D.-Meij-52019842;Ron G. Bout
中科院分区：
文献类型：
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作者：
M. A. A. V. D. Meij-M.-A.-A.-V.-D.-Meij-52019842;Ron G. Bout
总结许多关于雀的摄食效率的研究集中在脱壳时间与平均种子大小和鸟类大小的关系上。大型物种能够吃掉更大的种子，并且比小型物种更快地剥大种子。通常认为脱壳时间与咬合力有关。然而，很少有研究直接探讨脱壳时间，种子硬度和咬合力之间的关系。在我们的实验中，我们测量了两个类群的种子破碎鸟类的种子脱壳时间和最大咬合力。剥壳时间与最大咬合力以高度非线性的方式相关，并且在雌鱼和流苏鱼之间存在差异。具有与雌虫相同咬合力的鸡冠鱼需要更少的时间来破碎种子，但只有当种皮的强度接近它们的最大咬合力时。对于相对较软的种子，脱壳时间的差异变得非常小。初步的下颌运动分析提供的证据表明，这种差异，在脱壳时间之间的estrildids和fringillids是由脱壳技术的差异。这种技术差异不会影响咬合力，但会降低破裂尝试失败的可能性。最大咬合力的小幅增加的选择优势可能更多地与硬度低于最大咬合力的种子的脱壳时间的减少有关，而不是与鸟能够破解的种子硬度范围的增加有关。
SUMMARY Many studies on the efficiency of feeding in finches concentrate on husking time in relation to average seed size and bird size. Large species are capable of eating larger seeds and are able to husk large seeds faster than smaller species. It is generally assumed that husking time is related to bite force. However, there are very few studies that investigate the relationship between husking time, seed hardness and bite force directly. In our experiments we measured the seed husking time and the maximal bite force of two taxa of seed cracking birds. Husking time is related to maximal bite force in a highly non-linear way and differs between estrildids and fringillids. Fringillids with the same bite force as estrildids take less time to crack seeds, but only when the strength of the seed coat is close to their maximal bite force. For seeds that are relatively soft the difference in husking time becomes very small. A preliminary jaw motion analysis provides evidence that this difference in husking time between estrildids and fringillids is paralleled by a difference in husking technique. This difference in technique does not affect bite force as such, but decreases the chance of failed cracking attempts. The selective advantage of a small increase in maximal bite force may be related more to the decrease in husking time for seeds with hardness below the maximal bite force, than to the increase in range of seed hardness that the bird is able to crack.