Université Paris-Sud, Bâtiment 362, Orsay Cedex, France.
Oecologia. 2013 Sep;173(1):169-78. doi: 10.1007/s00442-013-2600-4. Epub 2013 Feb 13.
Predator-prey and host-parasite interactions and mutualisms are common and may have profound effects on ecosystems. Here we analyze the parasitic and mutualistic associations between three groups of organisms: the plant Artemisia maritima, bacteria, and a colonial seabird (the sandwich tern Sterna sandvicensis) that breeds in dense colonies covered in feces produced by both adults and chicks. A disproportionately large fraction of colonies of the sandwich tern in Denmark were located in patches covered by A. maritima. This association was specific for the densely colonial sandwich tern, but was not present for four other sympatric species of terns that breed in much less dense colonies. A. maritima reduced the abundance of pathogenic Staphylococcus on chicken eggshells in a field experiment. Recruitment by sandwich terns breeding in patches of A. maritima was 18 % higher than for sandwich terns breeding in the absence of A. maritima. A. maritima benefitted from the association with sandwich terns due to the supply of nutrients from feces and uneaten food lost by young. These findings are consistent with sandwich terns exploiting the association with A. maritima and its antimicrobial properties to improve their reproductive success, while sandwich terns and A. maritima are involved in a mutualistic interaction.
捕食者-猎物和宿主-寄生虫相互作用和共生关系很常见，可能对生态系统产生深远影响。在这里，我们分析了三组生物体之间的寄生和共生关系：植物黄花蒿、细菌和一种在密集的粪便覆盖下繁殖的群居海鸟（斑嘴鹈鹕）。在丹麦，大量的斑嘴鹈鹕繁殖地位于黄花蒿覆盖的斑块中。这种关联是针对密集繁殖的斑嘴鹈鹕的，但对于其他四种在密度较低的繁殖地繁殖的共生燕鸥来说并不存在。在一个野外实验中，黄花蒿减少了鸡蛋壳上致病性葡萄球菌的数量。在有黄花蒿的斑块中繁殖的斑嘴鹈鹕的繁殖成功率比在没有黄花蒿的地方繁殖的斑嘴鹈鹕高 18%。黄花蒿得益于与斑嘴鹈鹕的共生关系，因为它从粪便和幼鸟丢失的未食用食物中获得了营养。这些发现与斑嘴鹈鹕利用与黄花蒿及其抗菌特性的共生关系来提高其繁殖成功率一致，而斑嘴鹈鹕和黄花蒿则参与了互利共生的相互作用。
