Through a comprehensive analysis of 1,302 bird species residing in nine different archipelagos, the researchers examined 265 extinct species and 355 newly introduced species from 143 distinct species. The results demonstrated that bird communities on islands were once more morphologically diverse before human presence. Human-induced extinctions have disproportionately impacted certain types of birds, resulting in the loss of specific ecological roles.
Sayol highlighted that some extinct species had vital roles within their ecosystems that have not been effectively filled by other birds. For instance, giant flightless species like New Zealand’s moas and Madagascar’s elephant birds likely played the role of large terrestrial herbivores, similar to ungulates on continents, before being driven to extinction by human activities. The implications of such extinctions go beyond their direct effects, as functions like pollination and seed dispersal, crucial for maintaining a balanced ecosystem, can also be disrupted.
The study further revealed a disconcerting trend: as native birds face extinction and introduced alien species take their place, different archipelagos are gradually becoming more uniform in terms of trait diversity. Professor tіm Blackburn, co-author of the study, noted that certain bird groups, such as parrots and starlings, have been notably successful in establishing themselves outside their natural habitats. This phenomenon has led to increased homogeneity among islands as these same bird species populate various regions.
The study’s implications are clear: conservation efforts should prioritize the protection of functionally distinct threatened species. Co-author Alex Pigot, a senior research fellow at UCL, emphasized that it’s crucial to address the harmful losses to biodiversity driven by human actions. The study serves as a stark reminder of the need for comprehensive strategies to mitigate the ongoing impact of human activity on avian ecosystems.
