Bertolino Sandro, Montezemolo Nicola Cordero di, Perrone Aurelio
DIVAPRA (Department of Protection and Exploitation of Agricultural Resources) Entomology and Zoology, Via L. da Vinci 44, Grugliasco, Torino 10095 Italy.
Zoolog Sci. 2011 Jun;28(6):414-9. doi: 10.2108/zsj.28.414.
We used radiotelemetry to investigate resting sites habitat selection by introduced eastern cottontail (Sylvilagus floridanus) and native European hare (Lepus europaeus) under sympatric conditions. We tracked 24 hares and 34 cottontails in a protected area of northwestern Italy. Hares were found in different sites every week, while cottontails used the same site for two weeks, and occasionally for longer. It is supposed that this periodic nest switching reduces the risk of predation and parasitism. Hares and cottontails forms were located in different habitats and characterized by dense vegetation cover near the ground. This cover increased from winter to summer in both species, while in autumn it continued to increase in cottontails only, and decreased in hares. Cottontails selected shrubby habitats near the river, and avoided crop fields in all seasons. Hares were more adaptive in their search, using high herbs and shrubs all year round, wheat fields in spring, maize in spring and summer, and stubbles in winter. Arguably, partial niche differentiation is necessary to allow the coexistence of similar species. In our study area, hares and cottontails differentiated in the use of resting sites habitats, presumably so as not to compete in this part of their ecological niche.
我们利用无线电遥测技术,研究了在同域条件下引入的东部棉尾兔(Sylvilagus floridanus)和本土欧洲野兔(Lepus europaeus)对休息场所的栖息地选择。我们在意大利西北部的一个保护区追踪了24只野兔和34只棉尾兔。野兔每周会出现在不同的地点,而棉尾兔会在同一个地点停留两周,偶尔停留更长时间。据推测,这种周期性的巢穴更换降低了被捕食和寄生的风险。野兔和棉尾兔的活动区域位于不同的栖息地,其特点是地面附近植被茂密。两种动物的这种植被覆盖度从冬季到夏季都有所增加,而在秋季,只有棉尾兔的植被覆盖度继续增加,野兔的则减少。棉尾兔选择了靠近河流的灌木丛生栖息地,并在所有季节都避开农田。野兔在寻找栖息地方面更具适应性,全年都会利用高草和灌木,春季利用麦田,春夏利用玉米地,冬季利用茬地。可以说,部分生态位分化对于相似物种的共存是必要的。在我们的研究区域,野兔和棉尾兔在休息场所栖息地的利用上存在差异,大概是为了在其生态位的这一部分不产生竞争。