FELINE CANINES - COMMUNITY-WIDE CHARACTER DISPLACEMENT AMONG THE SMALL CATS OF ISRAEL
FELINE CANINES - COMMUNITY-WIDE CHARACTER DISPLACEMENT AMONG THE SMALL CATS OF ISRAEL
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DOI：
10.1086/285081
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发表时间：
1990-07-01
影响因子：
2.9
通讯作者：
YOMTOV, Y
中科院分区：
文献类型：
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作者：
DAYAN, T;SIMBERLOFF, D;YOMTOV, Y
以色列的三种同域、同位的小型猫科动物都具有强烈的两性二态性。因此，如果每个性别在形态上都是不同的，作为一个“形态物种”，那么就有六个形态物种可能相互竞争。这些形态物种的平均犬齿直径在对数尺度线上是非常均匀的（即，在大小排名中相邻形态物种之间的大小比例惊人地相等）。髁突基部的长度没有这种模式。同样的三个物种占据了从尼罗河三角洲到印度西北部的狭长地带。信德在以色列的另一端，那里的三个物种都要小得多。然而，犬齿直径似乎又一次在相邻大小排序的形态物种之间产生相等的大小比例。一种稍大一点的猫（Felis viverrina）占据了信德，但不在以色列。虽然我们没有在野外捕获的这种雌性动物，但我们从信德找到的一只雄性动物表明，如果把这种动物和其他物种加在一起，它会产生一系列8种形态物种，它们的犬齿直径大小比例相等。这是一个站得住脚的假设，即种内和种间的食物竞争选择了这些相等的犬科动物大小比例，也选择了相对于以色列同种动物的体型减小。根据这种假设，一般来说，更大的牙齿被用来杀死更大的猎物。对于猫来说，犬齿的大小可能与猎物种类的关系比髁突的长度更密切。然而，竞争假说必须是初步的，因为我们对这些物种的营养生态学知识的主要经验差距。猎物的大小分布是未知的，没有证据表明更大的犬科动物与更大的猎物相关，也不知道猎物是有限的。另一种假设是犬类在战斗中的表现或使用介导的行为学相互作用，包括种内和种间。这种相互作用是合理的，很可能导致一种流离失所的模式。经验上的差距阻碍了在假设之间做出明确的选择。无论如何，我们的研究结果与早期对mustelids的研究结果惊人的相似表明了一种共同的解释。
Each of the three sympatric, syntopic small cat species of Isreal is strongly sexually dimorphic. Thus, if each sex is viewed as morphologically distinct, as a "morphospecies," there are six morphospecies potentially competing with one another. The mean canine diameters of these morphospecies are remarkably evenly spaced on a log-scaled line (i.e., the size ratios between adjacent morphospecies in a size ranking are surprisingly equal). Condylobasal lengths show no such pattern. The same three species occupy a narrow band from the Nile delta to northwestern India. The Sind is at the other end of this band from Isreal, and all three species are substantially smaller there. However, the canine diameters again seem to produce equal size ratios between adjacent size-ranked morphospecies. A slightly larger cat (Felis viverrina) occupies the Sind but not Israel. Although we lack a wild-caught female of this species, the single male we have located from the Sind suggests that this species would, when added to the others, produce a series of eight morphospecies with equal size ratios for canine diameter. It is a tenable hypothesis that intra- and interspecific competition for food has selected for these equal canine size ratios and also for the decrease in the sizes of Sind animals relative to Israeli conspecifics. By such a hypothesis, larger teeth are used to kill larger prey, on the average. For cats, canine size is likely to be more highly correlated with prey species than is condylobasal length. However, the competitive hypothesis must be preliminary because of major empirical gaps in our knowledge of the trophic ecology of these species. The prey-size distributions are unknown, it has not been shown that larger canines correlate with larger prey, and it is not known that prey are limiting. An alternative hypothesis would entail ethological interactions mediated by canine display or use in fighting, both intra- and interspecifically. Such interactions are plausible and could well contribute to a pattern of displacement. The empirical gaps prevent a definitive choice between the hypotheses. In any event, the striking similarity of our result with that of an earlier study of mustelids suggests a common explanation.