The Xerces Society for Invertebrate Conservation last week petitioned the U.S. Department of the Interior to protect seven Hawaiian bee species under the Endangered Species Act. All seven species of these "yellow-faced bees" -- Hylaeus anthracinus, H. longiceps, H. assimulans, H. facilis, H. hilaris, H. kuakea and H. mana -- have seen tremendous declines since they were first observed just over a century ago. None exist outside the Hawaiian Islands.

The group is calling for "active management of natural areas" to protect these species in their native habitats to prevent them from disappearing

“Pollinators are keystone species in many ecosystems, but these Hawaiian yellow-faced bees are likely even more important since many Hawaiian native plant species are not well adapted to pollination by non-native pollinators,” Sarina Jepsen, endangered species coordinator at the Xerces Society in Portland, Ore., said in a statement.

The petitions were based on scientific surveys conducted by Karl Magnacca, a postdoctorate entomology researcher at the University of California, Berkeley. The research attempted to assess the population of the 60 known Hawaiian bee species. Magnacca's findings, published in the April 2007 issue of the journal Pacific Science:

•    Five of the 60 species still exist, but were not collected from one or more of the islands on which they were historically found

•    Seven were found to be restricted to endangered habitat

•    10 were considered to be very rare and potentially endangered

•    10 others could not be located and, according to Magnacca's paper "could be extinct"

According to the Xerces Society, threats facing these bees include habitat loss (especially coastal regions) caused by human development, wildfires, predation by invasive species (such as ants) and loss of native vegetation to invasive species. The bees "depend on an intact community of native plants and are mostly absent from habitats dominated by non-native plant species," Xerces says in its petitions.

Credit: Forest & Kim Starr