[The aerobic bacterial flora of songbird nests]

In the area around Ober- and Unterschleissheim, a medium term decrease in the singing bird population appears to be happening. Therefore, material from nesting-boxes (used for nesting or sleeping) was examined for bacterial contamination. Mainly gram positive bacteria were isolated which were considered to belong to the normal flora. The occurrence of Streptomyces spp. is described in the nesting material of Passeres probably for the first time. Enterobacteriaceae represent only a fraction of the total isolates, but are demonstrated relatively frequently in the nests of the Nuthatch (Sitta europaea) and nests of other non-identified bird spp., so that colonization of the intestinal tract with Enterobacteriaceae cannot be excluded. Surprisingly, bacteria of the aquatic habitats such as Alcaligenes, Bordetella, Aeromonas, Non-Cholera (NC)-Vibrio were isolated, although in small amounts. The occurrence of NC-Vibrio has not yet been described in singing birds. Nests with high numbers of gram negative rods were successful in most instances, therefore, there was no proof that aerobic bacteria are responsible for the decrease in the population.