Detritus decorations as the extended phenotype deflect avian predator attack in an orb-web spider
Detritus decorations as the extended phenotype deflect avian predator attack in an orb-web spider
复制标题
球网蜘蛛中的碎屑装饰作为扩展表型偏转鸟类捕食者的攻击
DOI：
10.1111/1365-2435.13636
复制
发表时间：
2020-09-06
影响因子：
5.2
通讯作者：
Zhang, Shichang
中科院分区：
文献类型：
--
作者：
Ma, Nina;Yu, Long;Zhang, Shichang
许多转移视觉引导的捕食者（如鸟类）攻击的策略在动物中已经进化了多次。由某些圆网蜘蛛物种建造的碎屑网装饰被认为是将鸟类捕食者的攻击从蜘蛛转向它们的网装饰。然而，这一功能及其适应意义的经验证据仍然缺乏。圆网蜘蛛，山地环蛛，用线性碎屑装饰它的网，包括蜕皮，卵囊，猎物遗骸和落叶。在本研究中，我们调查了是否碎屑装饰构建的C。山地蜘蛛转移了鸟类掠食者对蜘蛛的攻击。我们首先采用颜色建模，比较蜘蛛的身体和碎屑装饰着色的角度来看，国内小鸡和蓝山雀。然后，我们在实验室中使用幼稚的小鸡作为捕食者，通过实验测试了偏转假设。我们将小鸡放在一个笼子里，笼子里有一个有（S+）或没有（S-）蜘蛛的网，有（D+）或没有（D-）碎屑装饰（总共四种类型的网：S+D+，S+D-，S-D+和S-D-）在自然栖息地背景和白色背景下。我们发现C.无论是幼鸟还是蓝山雀，在这两种背景下，都无法将山地蜘蛛与它们的碎屑装饰区分开来。实验室捕食实验表明，在两种背景下，当蜘蛛的装饰物出现在网上时（S+D+;自然栖息地：20%，白色背景：30%），小鸡攻击蜘蛛的频率要比没有装饰物时（S+D-;自然栖息地：95%，白色背景：85%）低得多，导致更大的蜘蛛生存优势。我们还发现，蜘蛛和它们的装饰物的攻击率不是随机的;当蜘蛛和装饰物都出现时，装饰物比蜘蛛更容易被攻击，而不管装饰物与蜘蛛身体的表面积比（S+D+）。因此，我们的研究结果支持一个偏转，而不是隐藏假设的网页装饰。总之，我们的研究提供了证据表明，动物身体以外的扩展表型，可以转移鸟类捕食者的攻击，因此，可能会提高动物的健身。在本文的支持信息中可以找到一个免费的简明语言摘要。
A number of strategies that divert attacks of visually guided predators, such as birds, have evolved multiple times in animals. Detritus web decorations built by certain orb-web spider species are thought to deflect avian predator attacks away from spiders and towards their web decorations. Still, empirical evidence for this function and its adaptive significance is lacking. The orb-web spider,Cyclosa monticola, adorns its web using a linear detritus decoration consisting of moults, egg sacs, prey remains and leaf litters. In the present study, we investigated whether detritus decorations constructed byC. monticolaspiders divert attacks of avian predators away from spiders. We first employed colour modelling to compare spider bodies and detritus decoration colouration from the perspective of domestic chicks and blue tits. We then experimentally tested the deflection hypothesis in the laboratory using naive chicks as predators. We put the chicks in a cage containing a web either with (S+) or without (S-) a spider and either with (D+) or without (D-) detritus decoration (a total of four types of webs: S+D+, S+D-, S-D+ and S-D-) under both natural habitat background and white background. We found that the colour ofC. monticolaspiders is indistinguishable from that of their detritus decorations for both chicks and blue tits with both backgrounds. Laboratory predation experiments showed that with both backgrounds, chicks attacked the spiders much less frequently when their decorations were present on the webs (S+D+; natural habitat: 20%, white background: 30%) than when their decorations were absent (S+D-; natural habitat: 95%, white background: 85%), resulting in greater spider survival advantage. We also found that the rate of attack of spiders and their decorations was not random; the decorations were more likely to be attacked than spiders, regardless of the ratio of surface area of decorations to spider bodies when both spiders and decorations were presented (S+D+). Therefore, our results support a deflection, rather than concealment hypothesis for web decorations. In conclusion, our study provides evidence that the extended phenotypes beyond the animal bodies, can divert avian predator attacks, therefore, may improve the fitness of animals. A freePlain Language Summarycan be found within the Supporting Information of this article.