The Effect of Capture Method on Microbial Abundance in Plumage of Eastern Yellow Robins (Eopsaltria australis)

Students: Larynn Cutshaw and Nadya Sotnychuk
Mentor: Laura Tuhela-Reuning (Department of Botany-Microbiology)

Bird plumage is an ecosystem of microbes within the avian host, most of which are soil-dwelling organisms. We questioned how method of capture influences the microbial loads in plumage. Understanding the effect trap types have on microbe abundances can help us better refine methodologies in avian microbiology studies.

Bird plumage is an ecosystem of microbes within the avian host. Most of these organisms are soil-dwelling bacilli so birds with more soil contact tend to have higher microbial loads. While investigating whether Bacillus species are present in plumage of Australian birds, we questioned if trapping method influenced microbial loads. We expected microbial abundance on birds caught with mist nets, a device used on birds in flight, would be of a lower abundance than those captured with snap traps, a tool which restrains the bird in the soil. The abundance of microbes on Eastern Yellow Robins (Eopsaltria australis) captured in both trap types was compared by sampling each bird with Tryptic Soy Agar contact plates at the back, tail, and venter. After statistical analyses using t-Tests in SPSS, the data were significant overall (p = 0.004), but when comparing data from specific parts of the bird, capture method was only a significant factor on the back (p = 0.039; p = 0.055 and 0.125 on tail and venter, respectively). We assume that our methodologies have created a detection limit in our data, leaving our results inconclusive to whether or not method of capture is a factor in microbial abundance.