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The Thermal Preferences of Ecuadorian Butterflies of the Amazon
Checa, M.F., Barragan, A., Rodriguez, J. and Christman, M. 2009. Temporal abundance patterns of butterfly communities (Lepidoptera: Nymphalidae) in the Ecuadorian Amazonia and their relationship with climate. Annales de la Société Entomologique de France (NS) 45: 470-486.

What was done
Working within areas surrounding the Yasuni Scientific Research Station in the Ecuadorian Amazon inside the Yasuni National Park -- which together with the Huaorani Ethnic Reserve comprise 1.6 million hectares of forest and were declared by UNESCO in 1987 to constitute a Biosphere Reserve -- the authors studied the composition and structure of butterfly communities of the "rotting-carrion guild" of the Nymphalidae family over a period of 13 months (April 2002-April 2003), based on data obtained using traps baited with rotten shrimp that had been fermenting for 11-20 days.

What was learned
Checa et al. captured a total of 9,236 individual Nymphalidae butterflies representing 208 different species, two of which species had not previously been found in Ecuador, and two of which were determined to actually be "new" species that had not previously been found anywhere. In further analyzing their data, they discovered there was "a constant replacement of species throughout the year," and that "these communities had the highest species richness and abundance during the months with high temperatures [italics and bold added]." What was especially noteworthy about this finding was the fact that the mean temperature of their study area, as they describe it, "only varies over one degree during the whole year."

What it means
In discussing their results, the four researchers comment on "temperature's central role in the biology and life history of butterflies," noting that "several key processes for butterfly survival depend on regulation of internal temperature," including mimetism and fast flight (Chai and Srygley, 1990), and fecundity and longevity, which they say have been found to be "higher at higher temperatures (Karlsson and Wiklund, 2005)." Hence, they conclude that "the tight relationship between temperature and butterfly population levels" or abundance, which they observed, as well as butterfly species richness, which they also observed, will likely be "of major importance" for tropical butterflies within the context of surviving potential future global warming, prompting such butterflies to continually adjust their ranges throughout the year and between years, we would presume, so as to maintain themselves within the thermal regimes to which they are best adapted.

Chai, P., Srygley, B. 1990. Predation and the flight, morphology and temperature of neotropical rain-forest butterflies. The American Naturalist 135: 748-765.

Karlsson, B. and Wiklund, C. 2005. Butterfly life history and temperature adaptations: Dry open habitats select for increased fecundity and longevity. The Journal of Animal Ecology 74: 99-104.

Reviewed 16 June 2010