INTERSPECIFIC AND INTRASPECIFIC CHARACTER DISPLACEMENT IN MUSTELIDS
INTERSPECIFIC AND INTRASPECIFIC CHARACTER DISPLACEMENT IN MUSTELIDS
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DOI：
10.2307/1938210
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发表时间：
1989-10-01
期刊：
影响因子：
4.8
通讯作者：
YOMTOV, Y
中科院分区：
文献类型：
--
作者：
DAYAN, T;SIMBERLOFF, D;YOMTOV, Y
在寻找可能的社区范围内的字符位移（表现为相邻形态种之间的大小比例相等的大小排名），我们研究了黄鼠狼（Mustela）的北美和以色列的mustelid-viverrid公会。我们测量了髁基头骨长度（CBL）和最大直径的上犬齿（CsupL）的博物馆标本的两个或三个黄鼠狼物种同域在每个北美网站。我们发现大量的地理变异，并在每个网站，每个物种的性别二型性，以及性别二型性的程度的地理变异。同种男性和女性被视为单独的“形态种”，我们发现在每个站点的形态种的平均测量值的差异很小，几乎没有重叠的同域形态种之间的分布。尽管在地理上的变化，在7个网站的大小排序相邻的形态种之间的CsupL的比例是非常平等的，而CBL的类似分析表明，只有四个网站的比例趋于平等。当对性别进行单独分析时，两个变量基本上不存在相等比率的迹象。对于一个分类学上更多样化的“mustelid-viverrid”公会在以色列的5个物种，10个排名morphospecies有非常平等的大小比CsupL，但不是CBL，结果保持如果性别分别进行分析。这些结果，加上信息的mustelids的喂养行为，似乎与竞争性的性格位移的假设一致，但许多关键的数据仍然没有收集。没有直接的证据表明猎物仅限于任何一个公会，关于形态种实际吃什么的数据很少，也没有对这些物种的犬齿或头骨大小在杀死不同大小和类型猎物的能力中的作用进行功能分析。基于犬科动物展示或打斗的性选择很可能导致了两性异形。虽然缺乏直接观察，但犬科动物也可能在种间遭遇中用于威胁或战斗。然而，这种犬科动物的使用似乎不太可能解释体型比例相等的整个模式，因为物种内两性之间的性别选择的体型比例碰巧等于每个物种的雄性和下一个更大物种的雌性之间的体型比例，无论如何选择。
In a search for possible community-wide character displacement (manifested as equal size ratios between adjacent morphospecies in a size-ranking), we examined the weasles (Mustela) of North America and also the mustelid-viverrid guild of Israel. We measured condylobasal skull length (CBL) and maximal diameter of the upper canine (CsupL) on museum specimens of the two or three weasel species sympatric at each of eight North American sites. We found substantial geographic variation and, at each site, pronounced sexual dimorphism of each species, as well as geographic variation in the degree of sexual dimorphism. With conspecific males and females viewed as separate "morphospecies", we found little variance about the mean measurement for a morphospecies at each site, and almost no overlap of distributions between sympatric morphospecies. In spite of the geographic variation, at seven of the eight sites the size ratios for CsupL between adjacent morphospecies in a size-ranking were remarkably equal, while the analogous analysis for CBL showed ratios tending towards equality at only four sites. Indications of equal ratios were largely absent for both variables when sexes were analyzed separately. For a more taxonomically diverse "mustelid-viverrid" guild of five species in Israel, the 10 ranked morphospecies had extraordinarily equal size ratios for CsupL but not for CBL, a result maintained if sexes were analyzed separately. These results, plus information on feeding behavior of mustelids, seem consistent with a hypothesis of competitive character displacement, but many critical data remain uncollected. There is no direct evidence that prey are limiting to either guild, data are scant on what the morphospecies actually eat, and there is no functional analysis for these species of the role of canine or skull size in ability to kill prey of different sizes and types. Sexual selection based on canine display or fighting might well contribute to sexual dimorphism. Though direct observation is lacking, it is also possible that canines may be used in threats or fighting in interspecific encounters. However, it seems unlikely that such canine use could account for the entire pattern of size ratio equality, as it would be quite coincidental that size ratios sexually selected between sexes within species should happen to equal those, however selected, between the male of each species and the female of the next larger species.