Butterflies of Barro Colorado Island, Panama: Local Extinction since the 1930s

• Published in: PloS one 2015-08, Vol.10 (8), p.e0136623-e0136623
• Main Authors: Basset, Yves, Barrios, Héctor, Segar, Simon, Srygley, Robert B, Aiello, Annette, Warren, Andrew D, Delgado, Francisco, Coronado, James, Lezcano, Jorge, Arizala, Stephany, Rivera, Marleny, Perez, Filonila, Bobadilla, Ricardo, Lopez, Yacksecari, Ramirez, José Alejandro
• Format: Article
• Language: English
• Subjects: Animals; Bar codes; Birds; Breeding; Butterflies; Butterflies & moths; Butterflies - genetics; Butterflies - physiology; Conservation; Cryptic species; Deoxyribonucleic acid; Dispersal; DNA; DNA barcoding; DNA Barcoding, Taxonomic; Ecosystem; Extinct species; Extinction; Extinction (Biology); Extinction, Biological; Forests; Gene sequencing; Genetic aspects; Habitats; herbs; Host plants; Host specificity; Invertebrates; Islands; Lepidoptera; monitoring; Panama; Phylogeny; probability; Protection and preservation; Rainforests; Species extinction; Tropical Climate; Vertebrates
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0136623

Few data are available about the regional or local extinction of tropical butterfly species. When confirmed, local extinction was often due to the loss of host-plant species. We used published lists and recent monitoring programs to evaluate changes in butterfly composition on Barro Colorado Island (BCI, Panama) between an old (1923-1943) and a recent (1993-2013) period. Although 601 butterfly species have been recorded from BCI during the 1923-2013 period, we estimate that 390 species currently are breeding on the island, including 34 cryptic species, currently only known by their DNA Barcode Index Number. Twenty-three butterfly species that were considered abundant during the old period could not be collected during the recent period, despite a much higher sampling effort in recent times. These species are considered locally extinct from BCI and conservatively represent 6% of the estimated local pool of resident species. Extinct species represent distant phylogenetic branches and several families. The butterfly traits most likely to influence the probability of extinction were host growth form and wing size, independently of the relationships among butterfly species. On BCI, our most likely candidates for extinction are small hesperiids feeding on herbs (35% of extinct species). However, contrary to our working hypothesis, extinction of these species on BCI cannot be attributed to loss of host plants. In most cases these host plants remain extant, but they probably subsist at lower or more fragmented densities. Coupled with low dispersal power, this reduced availability of host plants probably has caused the local extinction of some of the species that we report. Many more bird than butterfly species have been lost from BCI recently, suggesting that small preserves may be far more effective at conserving invertebrates than vertebrates and, therefore, should not necessarily be neglected from a conservation viewpoint.