Department of Environmental Science and Policy, University of California, Davis, CA 95616, USA.
Proc Biol Sci. 2010 May 22;277(1687):1571-9. doi: 10.1098/rspb.2009.2128. Epub 2010 Jan 13.
Ecological invasions, where non-native species spread to new areas, grow to high densities and have large, negative impacts on ecological communities, are a major worldwide problem. Recent studies suggest that one of the key mechanisms influencing invasion dynamics is personality-dependent dispersal: the tendency for dispersers to have a different personality type than the average from a source population. We examined this possibility in the invasive mosquitofish (Gambusia affinis). We measured individual tendencies to disperse in experimental streams and several personality traits: sociability, boldness, activity and exploration tendency before and three weeks after dispersal. We found that mosquitofish display consistent behavioural tendencies over time, and significant positive correlations between all personality traits. Most notably, sociability was an important indicator of dispersal distance, with more asocial individuals dispersing further, suggesting personality-biased dispersal on an invasion front. These results could have important ecological implications, as invasion by a biased subset of individuals is likely to have different ecological impacts than invasion by a random group of colonists.
生态入侵是指非本地物种扩散到新的地区，生长到高密度，并对生态群落产生巨大的负面影响，这是一个全球性的主要问题。最近的研究表明，影响入侵动态的关键机制之一是个性依赖的扩散：扩散者比来源种群的平均个体具有不同的个性类型。我们在入侵的食蚊鱼（ Gambusia affinis）中研究了这种可能性。我们在实验溪流中测量了个体扩散的倾向以及几个个性特征：社交性、大胆性、活动性和探索倾向，在扩散之前和之后的三个星期进行了测量。我们发现，食蚊鱼随着时间的推移表现出一致的行为倾向，并且所有个性特征之间都存在显著的正相关关系。最值得注意的是，社交性是扩散距离的一个重要指标，不善于社交的个体扩散得更远，这表明在入侵前沿存在个性偏向的扩散。这些结果可能具有重要的生态意义，因为由偏向性个体组成的入侵比由随机的殖民者组成的入侵更有可能产生不同的生态影响。
