Differential survival of two minnow species under experimental sunfish predation: implications for re‐invasion of a species into its native range

摘要: Summary Predators have long been recognised as important drivers of community structure, and there is a growing literature that suggests predation can affect invasion success by limiting survival or recruitment potential invaders. Effects apex predators are well known, but increasing evidence mesopredators may also success. In southern Oklahoma (USA), red shiners (Cyprinella lutrensis, which considered highly invasive outside their native range) disappeared from several streams in they had historically the most abundant species. Subsequent to major flood, reappeared repeatedly one stream (Brier Creek) not become re-established, lines suggest predators, including sunfish mesopredators, be inhibiting re-invasion range. Over this same time course, another midwater minnow, bigeye shiner (Notropis boops), has remained common Brier Creek. In mesocosm experiment conducted 2009, exhibited differential survival, results suggested underlying cause. To test specifically for predation, we 2010 exposed equal numbers (n = 15 per mesocosm) two species: green (Lepomis cyanellus; n = 2 longear (L. megalotis; n = 1 mesocosm). There was no minnow species units without 2010, significantly more than survived units. Survival rates mesocosms with ranged 80 100% (mean 93.3%) 33.3 93.3% 74.1%) shiners. Feeding trials aquaria showed both predator could consume prey species, suggesting result inability eat either species. Although occurred natural along sunfish, failed re-established following abrupt decline, despite occasional occurrence these creeks recent years. Increased abundance conjunction presence underlie seemingly paradoxical situation fail re-invade habitat, persist system.