The Microbial Ecosystem of Avian Plumage 160 140

The Microbial Ecosystem of Avian Plumage 160 140 120 100 80 60 40 20 0 R 2 = 0. 9527 0 100 200 300 400 Number of Birds Sampled per Species Methods χ2=9. 848, df=4, p<0. 05 20% 15% 10% 5% 0% 0 30% 20% 10% e in ar M bi ee -p Tr -p ud M ro ro ro ivo ct Ne ng bi ng us g in ch at Fly -c ou Gr g in an le -g ge nd 0% lia Percentage of Birds With Feather. Degrading bacilli Passeridae Fringillidae Ichteridae Cardinalidae Emberizidae Thraupidae Parulidae 40% Primary Foraging Strategy 30% 4 χ2=50. 61, df=2, p<0. 0001 25% 20% 15% 10% 5% 0% Discussion χ2=38. 491, df=7, p<0. 001 50% 1 2 3 Degree of Feather Wear on Tail Percentage of Birds With Feather-Degrading bacilli by Topography Percentage of Birds With Feather-Degrading bacilli by Foraging Strategy l Percentage of Birds With Feather. Degrading bacilli 60% Ptilogonatidae Mimidae Turdidae Regulidae Trogloditidae Sittidae Paridae Hirundinidae Vireonidae Tyranidae Picidae Colombidae Scolopacidae Family Results • Feather-degrading bacilli occur in 42. 2% of birds • Feather-degrading bacilli common and widespread among birds • Birds with higher feather wear more likely to have feather-degrading bacilli • Foraging techniques influence presence of feather-degrading bacilli 25% χ2=102. 37, df=30, p<0. 0001 Hydrobatidae • 80% 70% 60% 50% 40% 30% 20% 10% 0% Fo • 500 30% Percentage of Birds With Feather-Degrading bacilli by the Level of Wear on Tail Feathers Percentage of Birds With Feather-Degrading bacilli by Family Ae ria • Birds were captured in mist nets Tail feathers rated for wear on a scale of 1 (few or no nicks) – 4 (missing and broken barbs) Cultures from tail, back, and venter grown on TSA agar plates Colonies counted and identified Percentage of Birds With Feather. Degrading bacilli • Percentage of Birds With Feather. Degrading bacilli Number of Birds with Feather-Degrading bacilli per Species by the Number of Individuals Sampled per 200 Species 180 Trochlidae • Bacilli produce βkeratinase, which degrades feathers • Species include: Bacillus licheniformis, B. subtilis, and B. pumilus • Puts selective pressures on birds, possibly influencing molt, color, and behavior Number of Birds with Feather. Degrading bacilli per Species Cody M. Kent, Edward H. Burtt, Jr. Department of Zoology, Ohio Wesleyan University, Delaware, OH, 43015 Tail Back Topography Venter • Feather-degrading bacilli common and widespread among birds • Birds with higher feather wear more likely to have feather-degrading bacilli • More common in birds that forage on ground • Feather-degrading bacilli more common on the venter, less on the tail