Male-biased dispersal in a fungus-gardening ant symbiosis.

For nearly all organisms, dispersal is a fundamental life-history trait that can shape their ecology and evolution. Variation in dispersal capabilities within a species exists and can influence population genetic structure and ecological interactions. In fungus-gardening (attine) ants, co-dispersal of ants and mutualistic fungi is crucial to the success of this obligate symbiosis.

Feather mite abundance varies but symbiotic nature of mite-host relationship does not differ between two ecologically dissimilar warblers.

Feather mites are obligatory ectosymbionts of birds that primarily feed on the oily secretions from the uropygial gland. Feather mite abundance varies within and among host species and has various effects on host condition and fitness, but there is little consensus on factors that drive variation of this symbiotic system. We tested hypotheses regarding how within-species and among-species traits explain variation in both (1) mite abundance and (2) relationships between mite abundance and host body condition and components of host fitness (reproductive performance and apparent annual survival).