• A recent study which analysed over 250 tropical and subtropical islands has pointed out that being isolated does not protect islands from alien species.
  • Rather, remote islands are more susceptible to alien invasion, be it from plants or mammals, the study found.
  • What really surprised us was to see that the isolation of an island had the opposite effects on native and non-native species richness.
  • Native species declined whereas non-native species numbers increased.
  • With the increase in anthropogenic activities like trade and transport, the biogeographical borders are broken down and the human-aided introduction of alien species has been on the rise.
  • The international team of researchers analysed large datasets of alien and native plants, ants, reptiles, mammals and birds on 257 tropical and subtropical islands, including India’s Andaman and Nicobar Islands and Lakshadweep.
  • Alien species bring in traits that native species lack.
  • They [alien species] have advantages compared to native island species due to their evolutionary history and the fact that they have evolved in a context where competition for resources is stronger and where other threats are more prominent
  • The report states that alien species have markedly changed fundamental biogeographical patterns of species richness on islands around the world.
  • There is also an urgent need to keep track of the already introduced alien species to save our islands, which are hotspots of biodiversity.