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Also, some species have a lip which does not flare outwards thatvisibly but is clearly thickened when viewed from the underside of shellaperture – examples are Partula navigatoria and P. garrettii
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除此之外,有些种类的壳唇在成熟时并不明显向外翻卷,但当从壳口下方观察时能发现它的壳口变得很厚——如Partula navigatoria和P. garrettii。
1.8 Behaviour
1.8.1 Activityand locomotion
In dry weatherpartulid snails seal themselves to their substrate but emerge and are moreactive after rain, especially at night, when they tend to move from restingunderneath leaves to actively foraging.
Experiments havedetermined the rate of dispersal of Partula taeniata at a mean of 2.8m (SD1.6m) movement from the sites of their original capture (Murray and Clarke1984) after 5 years. The maximum recorded gene flow measurements of 10 m after1 year, and 27 m after 13 years have been obtained. These measurementsconfirmed the hypothesis of very small neighbourhoods - approximately 200 m2 .Accelerated range expansion has occurred through the establishment of populationsby rare long-distance movements (passive dispersal) (Nichols and Hewitt, 1994).Recent re-introductions to the wild have shown strong upward dispersal afterrelease (Coote et al 2019)
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1.8 行为
1.8.1 活动
在天气较干燥时树蜗牛会把它们自己粘在附着的地方,但在雨后会探出壳外并变得更加活跃,尤其是在夜里,此时它们多从栖身的树叶下爬走并开始积极觅食。
经过5年的实验,已经由实验确定了Partula taeniata从原捕获地(以这样的方式)向周围扩散的范围均值为2.8米(标准差1.6米)(来自Murray和 Clarke1984),测量了两个基因流动距速率极值:1年10米和13年27米,证实了关于树蜗牛“小型种群”的假说——一个种群仅生存在约200平方米的狭小范围内。罕见的长距离移动能建立新的种群,加速该种生存范围的扩展(来自Nichols和Hewitt,1994)。
(除此之外),近年放归野外的树蜗牛展现了强大的垂直扩散能力。
1.8.2 Predation
Naturalpredators of Partulid snails would have been few but included native birds andlizards. Polynesians used to collect the snails for ornaments such as necklacesknown in Tahitian as ‘hei’, but there was no evidence of this significantlyaffecting wild populations. The introduction of alien predators has been themain recent threat (see 1.5).
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1.8.2 捕食
波利尼西亚树蜗牛的天敌原本很少,包括一些本地的鸟类和蜥蜴。波利尼西亚人收集蜗牛并制作成装饰品,如在塔希提岛被称为“hei”的项链。不过,没有证据表明这显著影响了树蜗牛的野外种群数量。
外来物种的入侵才是近代以来主要的威胁(见1.5)。
Also, some species have a lip which does not flare outwards thatvisibly but is clearly thickened when viewed from the underside of shellaperture – examples are Partula navigatoria and P. garrettii
——————————————————分割线—————————————————
除此之外,有些种类的壳唇在成熟时并不明显向外翻卷,但当从壳口下方观察时能发现它的壳口变得很厚——如Partula navigatoria和P. garrettii。
1.8 Behaviour
1.8.1 Activityand locomotion
In dry weatherpartulid snails seal themselves to their substrate but emerge and are moreactive after rain, especially at night, when they tend to move from restingunderneath leaves to actively foraging.
Experiments havedetermined the rate of dispersal of Partula taeniata at a mean of 2.8m (SD1.6m) movement from the sites of their original capture (Murray and Clarke1984) after 5 years. The maximum recorded gene flow measurements of 10 m after1 year, and 27 m after 13 years have been obtained. These measurementsconfirmed the hypothesis of very small neighbourhoods - approximately 200 m2 .Accelerated range expansion has occurred through the establishment of populationsby rare long-distance movements (passive dispersal) (Nichols and Hewitt, 1994).Recent re-introductions to the wild have shown strong upward dispersal afterrelease (Coote et al 2019)
——————————————————分割线—————————————————
1.8 行为
1.8.1 活动
在天气较干燥时树蜗牛会把它们自己粘在附着的地方,但在雨后会探出壳外并变得更加活跃,尤其是在夜里,此时它们多从栖身的树叶下爬走并开始积极觅食。
经过5年的实验,已经由实验确定了Partula taeniata从原捕获地(以这样的方式)向周围扩散的范围均值为2.8米(标准差1.6米)(来自Murray和 Clarke1984),测量了两个基因流动距速率极值:1年10米和13年27米,证实了关于树蜗牛“小型种群”的假说——一个种群仅生存在约200平方米的狭小范围内。罕见的长距离移动能建立新的种群,加速该种生存范围的扩展(来自Nichols和Hewitt,1994)。
(除此之外),近年放归野外的树蜗牛展现了强大的垂直扩散能力。
1.8.2 Predation
Naturalpredators of Partulid snails would have been few but included native birds andlizards. Polynesians used to collect the snails for ornaments such as necklacesknown in Tahitian as ‘hei’, but there was no evidence of this significantlyaffecting wild populations. The introduction of alien predators has been themain recent threat (see 1.5).
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1.8.2 捕食
波利尼西亚树蜗牛的天敌原本很少,包括一些本地的鸟类和蜥蜴。波利尼西亚人收集蜗牛并制作成装饰品,如在塔希提岛被称为“hei”的项链。不过,没有证据表明这显著影响了树蜗牛的野外种群数量。
外来物种的入侵才是近代以来主要的威胁(见1.5)。