Two field projects conducted during 1999-00 included a roadside bird- and vertebrate highway mortality survey in south-central Florida and an armadillo track census at Archbold. During 1974-81, counts of 21 bird species and road-killed vertebrates were conducted (Jan. & July) on a 505-km route including portions of 5 counties. These surveys were repeated in 2000 (Jan. & July) to detect any changes in bird populations and in species composition and in frequency of vertebrate highway mortality in the 18-year interval. Cattle Egret numbers were slightly to greatly reduced in 2000 compared to 1974-81 (see Fig., this page). Of nine raptor species surveyed, five showed declines and four species increases or no significant change. The northern harrier and burrowing owl experienced the most marked declines, 79% and 100%, respectively, while the osprey exhibited the greatest increase (11-fold) in 2000 compared to 1974-81. The observed trends in abundance of bird species were not obviously associated with long-term habitat changes along the route.

The coyote was added to the list of road-killed vertebrates in 2000, reflecting the recent increase of this species in south-central Florida. Among mammals, which account for about 74% of all road-killed vertebrates, armadillos were significantly fewer in 2000 than in the earlier years. The frequency of armadillo tracks in track censuses at Archbold was substantially lower in 2000 than in earlier years (1974-96). The evident reduction in armadillo numbers in the region is paralleled by a reported recent population decline in Texas and is not obviously correlated with any environmental factor.

Long-term data sets on the ecology of the herpetofauna of Archbold Biological Station and the southern Lake Wales Ridge are the source of two collaborative projects with James Layne. The first project, a manuscript in press with Florida Scientist, examines the relationship of species diversity and evenness with a 70-year absence of fire on Archbold’s sandhill habitat. The results of the study provide an important test for a conservation approach to sandy upland habitat management. Our second project concerns the ecology and biogeography of the herpetofauna of southern Florida. We are analyzing field and museum data for the region from the southern end of the Lake Wales Ridge south to the Florida Keys. We hope to update a similar study published 50 years ago.