Impacts of Man-Made Structures on Avian Community Metrics in 4 State Parks in Northwestern Arkansas

Abstract

Avian community metrics often differ between areas with no human disturbance and areas with high levels of human disturbance. However, the relationships between avian community metrics and smaller-scale disturbances are not as clear. Our goal was to investigate if avian abundance, richness, evenness, and diversity differed in areas with and without small-scale human developments. We used fixed-radius 50-m avian point counts to compare points which contained a man-made structure (n = 47), such as a picnic area, road, or campsite to those that did not contain a man-made structure (n = 181) at 4 state parks in Arkansas during 18 May – 7 August 2015. We used paired t-tests to compare points at the park scale and one-way ANOVAs or Kruskal-Wallis tests to investigate differences among the hiking and biking trails within parks. At the park scale, avian abundance (t₃ = -1.44, P = 0.246), richness (t₃ = ˗0.86, P = 0.453), diversity (t₃= 2.02, P = 0.137), and evenness (t₃ =˗0.37, P = 0.733) did not differ between points containing man-made structures and points without man-made structures. Species richness (F1,11 = 5.03, P= 0.047) and diversity (X^2₁ = 4.20, P = 0.040) were higher at points with man-made structures (Simpson’s D mean = 0.13 ± 0.01SE; S mean = 8.99 ± 0.70SE) at Pinnacle Mountain than points without man-made structures (Simpson’s D mean = 0.18 ± 0.03SE; S mean = 7.17 ± 0.47SE); abundance (F₁, ₁₁ = 1.43, P =0.257) and evenness (F₁, ₁₁ = 0.16, P = 0.695) did not differ among points. Within the 3 remaining parks, abundance (F₁,7-9 = 0.11 – 2.59, P = 0.152 – 0.748), richness (χ^2 ₁ = 0.300 – 1.68, P = 0.195 – 0.584), diversity (χ2 = 0.300 – 1.05, P = 0.305 – 0.584; F₁,7 =1.82, P = 0.219) and evenness (F₁,7-9 = 0.35 – 4.28, P =0.077 – 0.570) did not differ between points with and without man-made structures. Given the results of our analyses both at the park scale and within parks, it appears that small-scale man-made disturbances may have limited or no impact on avian community metrics.