Island biogeography as a test of reproductive interference

Abstract

Theoretical studies have predicted that reproductive interference must exclude either of the interacting species, but no testing of this prediction has ever been reported for natural populations. This study surveyed the distribution patterns of herbaceous Veronica plants, including one native and three alien species, to test whether the invasion of the alien species exerting reproductive interference excluded the native species. Results showed that the native species was repeatedly excluded from islands where an alien species invaded, exerting reproductive interference, and that other alien species had no significant effect on the native population survival. This survey also demonstrated that the native species altered its habitat from the ground to stone walls on the mainland where the alien species had been predominant. In the mainland populations, the fruit morphology differed from that of the islands, and the morphology in the mainland population seemed suitable for seed dispersion by ants at a stone wall habitat. We also surveyed the genetic differentiation among populations, the results of which did not support the native species genetically differentiated between mainland and island populations before the alien species invasion.These results strongly suggest that the reproductive interference excluded the recipient species at the population level and facilitated the habitat change. Additionally, results indicated that a series of field surveys of islands close to the mainland can be a powerful tool to test the ecological importance of reproductive interference.

When does reproductive interference occur? Predictions and data

“…In this sense, although this study used naturally coexisting species (at a regional scale), the experimental setting was similar to (1, 1) in Table . Similar study designs can be found in other work that has observed reproductive interference between coexisting species at the regional scale (e.g., Friberg et al, ; Hochkirch, Gröning, & Bücker, ; McLain & Pratt, ; Okuzaki et al, ; Takakura & Fujii, ).…”

Reproductive interference: ecological and evolutionary consequences of interspecific promiscuity

“…The final two contributions are empirical study reports. Takakura and Fujii (2015) report on the effect of reproductive interference on species distributions based on the field survey of biogeographic distribution patterns on various Japanese islands of four congeneric herbaceous plant species: a native species and three invasive species. They also provide evidence for habitat partitioning between the native species and an invasive species driven by reproductive interference on the Japanese main island of Honshu, where the invasive species is abundant.…”

When rarity has costs: coexistence under positive frequency‐dependence and environmental stochasticity

“…Rarity of conspecifics also increases the likelihood and costs of reproductive interference, in which mating attempts by one species have fitness costs on reproductively isolated co‐occurring heterospecifics (Gröning and Hochkirch, , Burdfield‐Steel and Shuker, , Tastard et al., , Kyogoku, ). Negative effects of heterospecific mating pressure can reduce use of otherwise suitable habitat (Takakura and Fujii, ), may be mediated by gamete interactions that reduce fertility (Hettyey et al., ), or even cause death. Each of these effects can impact population demography (Ting and Cutter, ).…”