Laboratory of Functional Morphology, Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Antwerpen, Belgium.
Behavioural Ecology and Ecophysiology Research Group, Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Antwerpen, Belgium.
Biol Open. 2024 Apr 15;13(4). doi: 10.1242/bio.060353. Epub 2024 Apr 11.
The dehusking of seeds by granivorous songbirds is a complex process that requires fast, coordinated and sensory-feedback-controlled movements of beak and tongue. Hence, efficient seed handling requires a high degree of sensorimotoric skill and behavioural flexibility, since seeds vary considerably in size, shape and husk structure. To deal with this variability, individuals might specialise on specific seed types, which could result in greater seed handling efficiency of the preferred seed type, but lower efficiency for other seed types. To test this, we assessed seed preferences of canaries (Serinus canaria) through food choice experiments and related these to data of feeding performance, seed-handling skills and beak kinematics during feeding on small, spindle-shaped canary seeds and larger, spheroid-shaped hemp seeds. We found great variety in seed preferences among individuals: some had no clear preference, while others almost exclusively fed on hemp seeds, or even prioritized novel seed types (millet seed). Surprisingly, we only observed few and weak effects of seed preference on feeding efficiency. This suggests either that the ability to handle seeds efficiently can be readily applied across various seed types, or alternatively, that achieving high levels of seed-specific handling skills does not require extensive practice.
食籽雀类对种子的脱壳是一个复杂的过程,需要喙和舌进行快速、协调和感觉反馈控制的运动。因此,高效的种子处理需要高度的感觉运动技能和行为灵活性,因为种子在大小、形状和种皮结构上有很大的差异。为了应对这种可变性,个体可能会专门针对特定的种子类型,这可能导致对首选种子类型的种子处理效率更高,但对其他种子类型的效率更低。为了验证这一点,我们通过食物选择实验评估了金丝雀(Serinus canaria)的种子偏好,并将这些偏好与喂食小的、纺锤形金丝雀种子和大的、球形大麻种子时的摄食表现、种子处理技能和喙运动学数据相关联。我们发现个体之间的种子偏好差异很大:有些个体没有明显的偏好,而有些个体几乎只吃大麻种子,甚至更优先选择新型种子(小米种子)。令人惊讶的是,我们只观察到种子偏好对摄食效率的影响很小。这表明,高效处理种子的能力可以很容易地应用于各种种子类型,或者,达到高度的种子特异性处理技能并不需要广泛的练习。