Aerobic performance does not affect social rank in female Red Jungle Fowl

1. Exercise capacity ultimately constrains behaviour, and therefore may inf luence social interactions. The hypothesis was tested that individual diffe rences in maximal rates of oxygen consumption ((V) over dot(O2max))- a prim ary determinant of sustainable exercise capacity - affect dominance hierarc hies in experimental all-female flocks of the highly social Red Jungle Fowl (Gallus gallus). It was also examined whether social rank could in rum inf luence (V) over dot(O2max) (which is quite plastic in most vertebrates), an d whether these relationships were influenced by a common and relatively be nign parasite, the intestinal nematode Ascaridia galli. 2. Substantial between-individual variation was found in (V) over dot(O2max ) that was significantly repeatable over time, but there was no indication that (V) over dot(O2max) was affected by A. galli infection. Stable social hierarchies were quickly established in 26 of 28 experimental flocks (each contained three females previously isolated from each other). Infection sta tus affected social rank, but there was no consistent pattern between rank and infection. 3. No indication was found that individual differences in (V) over dot(O2ma x) either predicted the social rank in newly formed flocks, or were affecte d by social status in established flocks.