This report analyzes long-term trends in the abundance of 24 species surveyed by park staff and volunteers from September 1992 through May 2021. Trend graphs and statistical analyses are included for each of the 24 species, as well as discussions of other factors that may explain the observed trends. The report also analyses trends for three shorter time periods defined by significant perturbations to the upper Wakulla River ecosystem: (1) invasion of the exotic hydrilla spurred by excess nitrogen in the spring (1992-2000), (2) the hydrilla management period (2000-2012) when mechanical harvesting and herbicides were aggressively used to combat the invasive exotic plant, and (3) the post-hydrilla management period (2012-2021) following the cessation of herbicide treatment in 2013.

Aggregate wildlife abundance, measured as total numbers of individual animals counted per survey both for all 24 species and for the six year-round resident species, decreased significantly over the 29.5 years of this monitoring project. Five species increased in abundance over this period, 14 decreased, and five exhibited no statistically significant long-term trend.

Upper Wakulla River Wildlife Abundance Trends 1992-May 2021.final