Dylewski Łukasz, Yosef Reuven, Myczko Łukasz
Institute of Zoology, Poznań University of Life Sciences, Poznań, Poland.
Eilat Campus, Ben-Gurion University of the Negev, Eilat, Israel.
PeerJ. 2017 May 31;5:e3288. doi: 10.7717/peerj.3288. eCollection 2017.
The number of species that specialize in pre-dispersal seed predation is relatively small. Examples of specialized pre-dispersal seed predators adapted to feeding on closed cones include vertebrate species like Crossbills, Squirrels, Nutcrackers and Woodpeckers. Seed predation selects against certain phenotypic features of cones and favors another phenotypic features. In this study, we document preferences of the Great Spotted Woodpecker () for specific traits in the cones of Norway spruce () and Scots pine (). We found that the Great Spotted Woodpecker prefers to feed on medium sized Norway spruce cones. The results suggest a disruptive selection that favors the extreme cone lengths in Norway spruce. In Scots pine, the woodpeckers avoided cones with large apophyses. Further, the selectivity for the specific characteristics of the cones is probably related to the configuration of the anvil, a place at which woodpeckers extract seeds from the cones. We think that the Great Spotted Woodpecker preferences in relation to the morphological characteristics of cones are a key to the design of the anvil in order to maximize the use of it as a tool for processing cones of both the Norway spruce and the Scots pine.
专门进行扩散前种子捕食的物种数量相对较少。适应以闭合球果为食的专门扩散前种子捕食者的例子包括交嘴雀、松鼠、坚果雀和啄木鸟等脊椎动物物种。种子捕食会淘汰球果的某些表型特征,并有利于其他表型特征。在本研究中,我们记录了大斑啄木鸟对挪威云杉和欧洲赤松球果特定特征的偏好。我们发现大斑啄木鸟更喜欢取食中等大小的挪威云杉球果。结果表明存在一种有利于挪威云杉极端球果长度的分裂选择。在欧洲赤松中,啄木鸟会避开具有大鳞片的球果。此外,对球果特定特征的选择性可能与砧座的结构有关,砧座是啄木鸟从球果中取出种子的地方。我们认为,大斑啄木鸟对球果形态特征的偏好是设计砧座的关键,以便最大限度地将其用作处理挪威云杉和欧洲赤松球果的工具。