The Indicator

As discussed on the indicator page, there are multiple approaches to reporting on animal species in farmland areas. One might be to report on the status of species that favor those habitats that existed before farmland was created in an area. Such an approach would, for example, focus on grassland birds in areas of the Great Plains— species that inhabited prairies that have now been converted to farmland. Another approach might be to focus on species that are able to take advantage of farmland landscapes—many game birds and small mammals, for example. Both of these approaches would be useful, but by themselves would be incomplete.

A more appropriate approach, recommended here, would be to focus on the full breadth of species that might inhabit farmlands. To follow the examples above, this would include both grassland birds and game birds and small mammals. Such an approach has been suggested, based on expectations that one might encounter a variety of birds in different regions of the nation. An index could be developed based on comparing this expectation with data on the presence of birds on farmlands in that region—data that may already be available for a significant percentage of farmlands (Breeding Bird Survey, http://www.mbr-pwrc.usgs.gov/bbs/bbs.html; additional information on such an approach toward determining an index of bird “integrity” can be found at htpp://landscape.forest.wisc.edu/LandscapeEcology/Articles/v7i2p137.pdf).

Several reviewers of this report recommended that this indicator focus on domestic animals—their numbers, condition, diversity, and the like. The Farmlands Work Group determined that it was appropriate to focus on the status and trends in wild species as part of this measure (which is intended to describe ecosystem conditions). A measure describing domestic animals would have been appropriate as part of the “human use” set of indicators, but was determined not to be of sufficiently high priority for inclusion.

The Data Gap

There are two major national-scale sources of information on species population status and trends. These include NatureServe’s compilation of information from state-based Heritage programs, which provides status information on a global, national, and state basis (www.natureserve.org) for a large number of species, and the U.S. Geological Survey’s Breeding Bird Survey (http://www.mbr-pwrc.usgs.gov/bbs/bbs.html), which provides population trend information for a large number of resident birds of North America.

Both programs provide information on a geographic scale that is usually larger than and is not limited to farmlands. Thus, it is likely that it would be necessary to undertake additional work to target these data only to farmlands.