Growth of induced feathers in photostimulated American Tree Sparrows

Article Abstract:

The hypothesis that the use of ptilochronology as a measure of the nutritional status of free-ranging birds may be affected by non-nutritional factors of feather growth was tested by means of a photostimulation experiment done on Tree Sparrows (Spizella arborea). The results showed that light-induced hormonal interactions control the duration of rectrix growth while the growth rate as revealed by growth bar width is nutritionally controlled. This indicates that ptilochronology is a reliable measure of feather growth rate.

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Communities of cloacal bacteria in tree swallow families

Article Abstract:

The cloacal bacteria of tree swallows on the campus grounds of Grand Valley State University, Ottawa County, MI, were examined to determine the pathogenic development of bacteria communities, prevalence patterns and relationships between bacteria loads and nestling size for both adult and nestling cloacae. All sampled swallows were positive for at least one bacteria type, although cloacal bacteria presence may be greater in tree swallows than in black-capped chickadees.

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Cloacal microbes in House Sparrows

Article Abstract:

Research is presented concerning the occurrence of fungi and bacteria in the cloaca of adult House Sparrows. The connection between the transfer of microbes during copulation and egg failure is investigated.

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