The history of anthropogenic disturbance and invasive alien species impact on the indigenous avifauna of the Ogasawara Islands, southern Japan

Human-induced disturbances, particularly the introduction of invasive mammals, have significantly impacted the indigenous avifauna of the Ogasawara Islands. The study reveals that seven endemic bird species or subspecies have gone extinct, and five breeding populations have disappeared from the archipelago since modern colonization began in 1830. Key threats include habitat loss, overhunting, and predation by invasive species like goats, cats, and rodents. While eradication efforts for these invaders have shown partial success—such as goat removal leading to vegetation recovery and cat removal aiding the recovery of the Ogasawara pigeon (Columba janthina nitens)—unintended ecological consequences have also emerged. For instance, removing goats allowed invasive plants to proliferate, while eliminating cats may have increased rodent populations. The study underscores the need for adaptive management strategies that account for complex species interactions and monitor ecosystem changes to avoid counterproductive conservation outcomes.

KAWAKAMI, K. (2019). 小笠原諸島における撹乱の歴史と外来生物が鳥類に与える影響. Japanese Journal of Ornithology, 68(2), 237–262. https://doi.org/10.3838/jjo.68.237