Butterfly flight morphology differs between canopy and understorey in a tropical rainforest community

1. Studies of altitudinal and latitudinal gradients in temperate areas often associate landscape structure and climate with animal morphology. In tropical rainforests there is a shift in conditions between the canopy and understorey. Butterfly communities have different compositions in these strata. This may imply that canopy and understorey butterflies may be under different selection pressures related to their flight morphology. 2. For riodinid butterflies in the Neotropics, it has been suggested that flight activities in the canopy and understorey are associated with different suites of morphological traits. However, this has rarely been tested in other groups of lepidopterans. 3. We examined data collected over five years in a long-term sampling project to describe the differences between canopy and understorey butterfly flight morphology in nymphalid species in the highly diverse Chocó rainforest. We measured variables including wing-area to thoracic-volume ratio, aspect ratio, and the relative distance to wing centroid. We explored whether canopy and understorey species had different allometric combinations of wing-areas and thoracic-volumes. Using independent contrasts based on a phylogeny of the Nymphalidae clade, we tested the hypothesis that low wing-area to thoracic-volume ratios were associated with a preference for living in the canopy in forest ecosystems. We also expected that understorey butterflies would have shorter distances to the wing centroid and higher aspect ratios as a possible compensation for a presumed higher wing-area to thoracic-volume ratios. 4. Butterfly species living in the canopy and understorey presented different combinations of wing-areas and thoracic-volumes. We confirmed the hypothesis that the preference for canopy of different butterfly species was significantly associated with low wing-area to thoracic-volume ratios. However, the preference for canopy was also associated with higher aspect ratios and no association was found with the relative distance to the wing centroid. 5. Our results suggest that marked differences in the environmental conditions between the canopy and the understorey subsystems in the tropical rainforests may be a factor shaping flight morphology of Nymphalidae butterflies

• Autor Principal: Mena González, Diego Sebastián (author)
• Formato: bachelorThesis
• Publicado: 2017
• Subjects: Butterflies; morphology; tropical rainforest; biodiversity; canopy
• Acceso en liña: https://repositorio.puce.edu.ec/handle/123456789/20543