McCairns R J Scott, Fox Michael G
Département de Biologie, Université Laval, Quebec, QC, Canada, G1K 7P4.
Oecologia. 2004 Jul;140(2):271-9. doi: 10.1007/s00442-004-1580-9. Epub 2004 May 15.
We investigated habitat selection in a trophically dimorphic population of pumpkinseed sunfish (Lepomis gibbosus) to determine whether littoral and limnetic ecotypes exhibit habitat or site fidelity. A transplant experiment was conducted, in which 998 pumpkinseeds captured from littoral and limnetic sites were marked and released in either the site of capture, the nearest site of the same habitat type, or the nearest site of the opposite habitat type. Daily recapture attempts over the course of the reproductive and growing season provided a 25% recapture rate, 40% of which were recaptured on multiple occasions at the same site. Site fidelity was very high in both ecotypes. Results estimated with a multi-state transition model indicated that the probability of a transplanted pumpkinseed returning to its site of origin ranged from 74% for limnetic pumpkinseeds released into a different limnetic or littoral site, to 93% for littoral pumpkinseeds released into a limnetic site. Furthermore, the probability of a pumpkinseed being recaptured at its site of origin if not transplanted was estimated at 97 and 98% for limnetic individuals and littoral individuals, respectively. Discriminant Function Analysis of helminth parasite loads sampled from littoral and limnetic individuals could classify site of origin with 96-100% accuracy, suggesting that the habitat and site fidelity patterns observed with mark-recapture are indicative of long-term habitat segregation of the two forms. The results of our experiment provide compelling evidence of correlated habitat selection as a function of home range fidelity within both ecotypes of a subtly dimorphic species. Such behaviour could have a significant effect on present or future gene flow.
我们对具有营养形态二态性的蓝鳃太阳鱼（Lepomis gibbosus）种群的栖息地选择进行了研究，以确定沿岸型和敞水区型生态型是否表现出对栖息地或地点的忠诚度。进行了一项移植实验，从沿岸和敞水区捕获了998条蓝鳃太阳鱼，对其进行标记后，将它们放回到捕获地点、最近的相同栖息地类型地点或最近的相反栖息地类型地点。在繁殖和生长季节进行的每日重新捕获尝试获得了25%的重新捕获率，其中40%是在同一地点多次被重新捕获的。两种生态型对地点的忠诚度都非常高。用多状态转换模型估计的结果表明，移植的蓝鳃太阳鱼回到其原生地点的概率，对于放入不同敞水区或沿岸区地点的敞水区蓝鳃太阳鱼来说，范围在74%，而对于放入沿岸区地点的沿岸区蓝鳃太阳鱼来说为93%。此外，对于未被移植的蓝鳃太阳鱼，如果在其原生地点被重新捕获，敞水区个体和沿岸区个体的概率分别估计为97%和98%。对从沿岸区和敞水区个体采集的蠕虫寄生虫负荷进行判别函数分析，能够以96%-100%的准确率对原生地点进行分类，这表明通过标记重捕观察到的栖息地和地点忠诚度模式表明了这两种形态在长期的栖息地隔离。我们实验的结果提供了令人信服的证据，表明相关栖息地选择是一个微妙二态性物种的两种生态型内家域忠诚度的函数。这种行为可能对当前或未来的基因流动产生重大影响。
