Department of Biology, Boston University, 5 Cummington Street, Boston, MA 02215, USA.
Biol Lett. 2012 Oct 23;8(5):887-9. doi: 10.1098/rsbl.2012.0468. Epub 2012 Jul 25.
Spatial contagion occurs when the perceived suitability of neighbouring habitat patches is not independent. As a result, organisms may colonize less-preferred patches near preferred patches and avoid preferred patches near non-preferred patches. Spatial contagion may thus alter colonization dynamics as well as the type and frequency of post-colonization interactions. Studies have only recently documented the phenomenon of spatial contagion and begun to examine its consequences for local recruitment. Here, we test for spatial contagion in the colonization of arboreal egg clutches of red-eyed treefrogs by a frogfly and examine the consequences of contagion for fly recruitment. In laboratory choice experiments, flies oviposit almost exclusively on clutches containing dead frog eggs. In nature, however, flies often colonize intact clutches without dead eggs. Consistent with predictions of contagion-induced oviposition, we found that flies more frequently colonize intact clutches near damaged clutches and rarely colonize intact clutches near other intact clutches. Moreover, contagion appears to benefit flies. Flies survived equally well and suffered less parasitism on clutches lacking dead eggs. This study demonstrates how reward contagion can influence colonization dynamics and suggests that colonization patterns caused by contagion may have important population- and community-level consequences.
当相邻生境斑块的可感知适宜性不独立时，就会发生空间传染。因此，生物可能会在偏好斑块附近的较不偏好斑块上殖民，而避免在非偏好斑块附近的偏好斑块上殖民。空间传染可能会改变殖民动态，以及后殖民化相互作用的类型和频率。研究人员最近才记录了空间传染现象，并开始研究其对局部招募的影响。在这里，我们测试了树蛙卵在树上产卵的空间传染现象，并研究了传染对蝇类招募的影响。在实验室选择实验中，蝇类几乎只在含有死蛙卵的卵上产卵。然而，在自然界中，蝇类经常在没有死卵的情况下殖民完整的卵。与传染诱导产卵的预测一致，我们发现蝇类更频繁地在受损卵附近的完整卵上殖民，而很少在其他完整卵附近的完整卵上殖民。此外，传染似乎对蝇类有利。蝇类在缺乏死卵的卵上的存活率相同，寄生率也较低。这项研究表明了奖励传染如何影响殖民动态，并表明由传染引起的殖民模式可能对种群和群落水平有重要影响。
