Early Onset of Incubation and Eggshell Bacterial Loads in a Temperate-Zone Cavity-Nesting Passerine

[摘要] Abstract. It has been hypothesized that incubation begins before laying is completed because it controls bacterial growth on eggshells and infection of eggs. If so, early incubation should be associated with decreased abundance of bacteria on eggshells. There is no detailed information on incubation during daytime or nighttime during laying and its association with bird eggshells' bacterial loads. We used temperature sensors placed in contact with eggs and connected to data-loggers to measure early incubation by females of the Pied Flycatcher, Ficedula hypoleuca, a hole-nesting passerine, beginning with laying of the third egg (day 3). Incubation usually began with laying of the fourth egg (day 4), the modal clutch size in our population being six. We sampled heterotrophic bacteria on eggshells from the whole clutch soon after it was completed. We used colony-forming units counted on trypticase soy agar to estimate bacterial loads. Clutches incubated more intensively during daytime on day 4 and also durin...

[学科分类] 动物科学

[关键词] behavioral antimicrobial defenses;culturable heterotrophic bacteria;eggshells;Ficedula hypoleuca;onset of incubation