The Bacterial Community Found on the surface Purple Martin (Progne subis) Eggs

Beth A. Potter1, *, Mary M. Sperry1, Dan D. Hoang1, Kaitlin C. Pander1, Sean G. Weaver1, Aimee N. Day1, Kelly M. Hedderick1, Michael A. Rutter1, Robert A. Aeppli2
1 School of Science, The Behrend College, Pennsylvania State University, Erie, Pennsylvania, USA
2 Purple Martin Conservation Association, Tom Ridge Environmental Center, Erie, Pennsylvania, USA

© 2017 Potter et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: ( This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Penn State Behrend, 4205 College Drive, Erie, PA 16563, USA; Phone: 814-898-6510, Fax: 814-898-6213, Email:



The community of microorganisms that lines the surface of avian eggs is the first line of defense against infection by pathogenic bacteria. The protective role of this community is derived from its composition and several studies have focused on identifying the bacterial components. While a diverse group of avian species has been studied, multiple species within the same family have not been independently studied. This depth is necessary to determine the degree of flexibility or plasticity within the community.


The goal of this study was to identify the bacterial microorganisms found lining the eggshells of an avian species classified within the Hirundinidae family, the Purple Martin (Progne subis). Culture-dependent techniques revealed a predominance of Pseudomonas before and after clutch completion.


Interestingly our results correlate with studies involving Pied Flycatchers, House Wrens, and Eurasian Magpies rather than Tree and Violet-Green Swallows.


Given the variances between Pied Flycatchers, House Wrens, Eurasian Magpies and Purple Martins in regard to breeding habitat, diet, nest construction, and incubation behaviors, we hypothesize that a strong selective force may be provided by uropygial gland secretions or preen oil.

Keywords: Purple Martin, Eggshell Bacterial Community, Uropygial gland secretions, Culture-dependent techniques, Pseudomonas, Hirundinidae family.