Assessment of avian communities for conservation potential in central sands Wisconsin agroecosystems

Background/Question/Methods Agricultural intensification has reduced the amount of suitable habitat for wildlife species. Bird populations are greatly impacted by habitat loss due to land use changes (Green et al 2005). Uncultivated areas have been shown to preserve ecosystem services (Bushkirk 2004), and are increasingly being viewed as places of conservation (Sotherton 1998). The Wisconsin Healthy Grown® Potato ecolabel encourages growers to incorporate restoration strategies into a whole-farm approach to management. Our research aims to inform these restoration plans by assessing the diversity of avian communities in uncultivated habitats surrounding potato fields in central Wisconsin. We hypothesized that 1) bird species richness would be highest in managed habitats that had undergone habitat restoration toward historical (ca. 1840) oak savanna, and 2) the richness of desirable bird species would be highest in these managed habitats undergoing restoration. During 2006 and 2007, we surveyed birds using 50-meter, fixed-radius point counts and measured various habitat characteristics on the non-crop habitats adjacent to potato fields of six Healthy Grown farms. Results/Conclusions An analysis of variance (ANOVA) test (p=0.02) and post Tukey HSD test on 2006 data showed that bird species richness was significantly higher in habitats that have undergone restoration to historical oak savanna and unrestored forested habitats than grassy field margins or pine plantations. The number of desirable bird species (as defined by Wisconsin's wildlife action plan) was highest in the grassy field margins and lowest in the pine plantations. In 2007, the pine plantation sites were excluded and two additional community types, wetland and oak woodland, were added. In 2007, bird species richness was found to be significantly higher in wetlands, forested and oak woodlands than in weedy habitats (p-value = 0.0001). Our research suggests that preserving or restoring non-crop lands on farms may improve their capacity to provide suitable habitat for many declining bird species, such as the Red-headed Woodpecker, Veery or Grasshopper Sparrow.