title: Droppings of wild birds
design: Microbial DNA was extracted from fecal samples using the E.Z.N.A. Stool DNA Kit (Omega Bio-tek, Norcross, GA, USA) following the manufacturers protocol. The V4V5 region of the bacterial 16S rRNA gene was amplified by PCR using primers 515F (5-GTGCCAGCMGCCGCGG-3) and 907R (5-CCGTCAATTCMTTTRAGTTT-3). Each 20 L PCR reaction contained 4 L of 5 FastPfu Buffer, 2 L of 2.5 mM dNTPs, 0.8 L of each primer (5 M), 0.4 L FastPfu Polymerase, and 10 ng of template DNA. PCR conditions were 95 C for 2 min, followed by 25 cycles of 95 C for 30 s, 55 C for 30 s, and 72 C for 30 s, with a final extension at 72 C for 5 min. Amplicons were purified from 2% agarose gels using the AxyPrep DNA Gel Extraction Kit (Axygen Biosciences, Union City, CA, USA).