Suffering at hands of one-two punch.

• Position: Butterflies

Butterflies are reeling from a one-two punch of climate change and land development, claims an analysis led by University of California, Davis, butterfly specialist Arthur Shapiro. "Butterflies are not only charismatic to the public, but widely used as indicators of the health of the environment worldwide," notes Shapiro, professor of evolution and ecology. "We found many lowland species are being hit hard by the combination of warmer temperatures and habitat loss."

The results are drawn from Shapiro's 35-year database of butterfly observations made twice monthly at 10 sites from sea level to tree line. This database is unique in science for its combination of attributes: one observer (which reduces errors); very long-term, multiple sites surveyed often; a large number of species (more than 150); and attendant climatological data.

The most significant findings include:

* Butterfly diversity (the number of different species present) is falling fast at all of the sites near sea level. It is declining more slowly or holding roughly constant in the mountains, except at tree line.

* At tree line, butterfly diversity actually is going up, as lower-elevation species react to the warming climate by moving upslope to higher, cooler elevations.

* Diversity among high-elevation butterflies is beginning to fall as temperatures become uncomfortably warm for them and, as Shapiro points out, "There is nowhere to go except heaven."

Shapiro and his colleagues--using a battery of statistical approaches--conclude that climate change alone cannot account in full for the deteriorating low-elevation numbers. Land-use...