The butterflies of Barro Colorado Island, Panama: local extinction since the 1930s

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 usedpublished lists and recent monitoring programs to evaluate changes in butterfly compositionon 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 the1923–2013 period, we estimate that 390 species are currently 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 couldnot be collected during the recent period, despite a much higher sampling effort in recenttimes. We consider these species locally extinct from BCI and they conservatively represent6% of the estimated local pool of resident species. Extinct species represent distant phylo-genetic branches and several families. The butterfly traits most likely to influence the proba-bility of extinction were host growth form, wing size and host specificity, independently ofthe phylogenetic relationships among butterfly species. On BCI, most likely candidates forextinction were small hesperiids feeding on herbs (35% of extinct species). However, con-trary to our working hypothesis, extinction of these species on BCI cannot be attributed toloss of host plants. In most cases these host plants remain extant, but they probably subsistat lower or more fragmented densities. Coupled with low dispersal power, this reducedavailability of host plants has probably caused the local extinction of some butterfly species.Many more bird than butterfly species have been lost from BCI recently, confirming thatsmall preserves may be far more effective at conserving invertebrates than vertebrates and,therefore, should not necessarily be neglected from a conservation viewpoin

Pervasive mimicry in flight behavior among aposematic butterflies

Flight was a key innovation in the adaptive radiation of insects. However, it is a complex trait influenced by a large number of interacting biotic and abiotic factors, making it difficult to unravel the evolutionary drivers. We investigate flight patterns in neotropical heliconiine butterflies, well known for mimicry of their aposematic wing color patterns. We quantify the flight patterns (wing beat frequency and wing angles) of 351 individuals representing 29 heliconiine and 9 ithomiine species belonging to ten color pattern mimicry groupings. For wing beat frequency and up wing angles, we show that heliconiine species group by color pattern mimicry affiliation. Convergence of down wing angles to mimicry groupings is less pronounced, indicating that distinct components of flight are under different selection pressures and constraints. The flight characteristics of the Tiger mimicry group are particularly divergent due to convergence with distantly related ithomiine species. Predator-driven selection for mimicry also explained variation in flight among subspecies, indicating that this convergence can occur over relatively short evolutionary timescales. Our results suggest that the flight convergence is driven by aposematic signaling rather than shared habitat between comimics. We demonstrate that behavioral mimicry can occur between lineages that have separated over evolutionary timescales ranging from <0.5 to 70 My