Cleaning House: Microbial ecology of passerine nest boxes in relation to environmental and nest constituent factor
B. Blevins, J. Caughron, J. Davis
Birds choose nest locations and construct nests out of varying materials for a variety of reasons, potentially including control of the microbial environment. Several studies have demonstrated that specific nesting materials may have antimicrobial properties, but the influence of nesting materials, nest location, and species influences on microbial populations remains relatively under-explored. In this study, bacterial samples were collected from bird boxes in southeastern Virginia in late summer, while recording various environmental features (orientation, age, construction materials, nest materials and type, and plants in the surrounding habitat). Bacterial samples were stored and analyzed using ethanol extraction and terminal restriction fragment length polymorphism (T-RFLP) assay to identify various bacterial colonies and how they differ between the bird nests. Here we describe our results, highlighting correlations between bacterial populations and features of the nest itself.
In vitro investigation of antimicrobial properties of
passerine nesting materials
Birds choose their nesting materials from a wide variety of options for a range of reasons. One of these reasons may be to control the microbial environment within the nest. While there have been various studies on the relationship between nesting materials and presence of parasitic hosts, few studies have attempted to show relationships with bacterial growth. In this study we compare the antimicrobial activity of several common nesting materials (e.g., red pepper, cedar, lavender, and straw). Each nesting material was ground to ensure consistency and then sterilized with UV light. Sterilized samples were added to nutrient broth containing a known quantity of Escherichia coli. After incubation, we performed serial dilutions and plated appropriate dilutions. We used eosin methylene blue agar plates to allow for selection and differentiation of E. coli. We calculated survival of E. coli for each nesting material and identified correlations between growth and antimicrobial activity. We will discuss initial results from our studies as well as implications for nest-structure and microbial ecology.