Thomas, JA, MG Telfer, DB Roy, CD Preston, JJD Greenwood, J Asher, R Fox, RT Clarke, and JH Lawton. Comparative losses of British butterflies, birds, and plants and the global extinction crisis. Science 303:1879-1881.
RELEVANT TO: SPECIES
MONITORING
DESCRIPTION
This article describes "the most comprehensive data sets in the world of changing status" for butterflies, birds, and plants. Using more than 20,000 volunteer recorders over Britain's 228,073 square kilometers, researchers compared presence of all 1,254 native vascular plant species (1954-1960 compared to 1987-1999); all 201 native breeding butterfly species (1970-1982 with 1995-1999); and all 58 native breeding butterfly species (1970-1982 and 1995-1999). Each survey achieved 98% to 100% cover of the 28,61 10-km grid squares of England. For each species, change in status was measured as the difference in the total number of 10-km grid squares occupied in each census period. Earlier studies have shown that range changes at this scale are closely correlated with trends in the mean size of individual butterfly and bird populations. Range changes are thus a surrogate for abundance.
MAJOR FINDINGS
- Declines:
- 28% of native plant species
- 54% of native bird species
- 71% of butterfly species
- The insect population decreases may foreshadow future, similar decreases in birds and plants because "insect populations typically respond more rapidly to adverse environmental change than longer-lived organisms or those with dormant propagules." (p. 1880).
- The declines in Britain are notable because "few exotics have colonized British ecosystems" compared to many other locations with higher rates of native endemism.
- The authors note that freshwater invertebrates (mussels, crayfish) have "much the highest recorded extinction rates among all listed taxa." (p. 1880)
- "Certainly the main drivers of change in British plant, bird, and butterfly populations are the same processes responsible for species' declines worldwide."
(p. 1880)
QUESTIONS RAISED FOR THE THREE FORESTS
- Does this study heighten a sense of responsibility regarding the special role for federal public lands in providing habitat for the nation's declining native biodiversity?
- Do the Three Forests deny that declines in native species similar to those recorded in this British study would be happening in the Three Forests? If so, on what basis?
RELEVANCE TO FOREST MANAGEMENT
- Use of volunteer, quality-controlled data (e.g., Audubon breeding bird surveys, independent studies) must be incorporated into Forest management, because Forest monitoring is currently vastly under-funded.
- Analogous data, e.g., that from Britain, must be considered applicable to management decisions on the three Forests in the absence of evidence that insect, plant, and bird declines are not occurring.
- The Biotic Condition Index is important for stream surveying, as invertebrate populations respond sensitively to habitat change.
- All native species are of importance in Forest management.
- Commitments to monitoring species decline must be mandatory in the Forest Plan. Otherwise, species silently slide toward extinction, with no accountability by the Forest Service.