This is a male in basic (non-breeding plumage). Its scapular feathers are raised as this bird actively chased off competitors. This is a common widespread Palearctic shorebird famous for forming leks in which polygamous males strut their flamboyant breeding plumes competing with other males for the attention of the much smaller females. In India, this species is a migrant and winter visitor. It was formerly placed in the monotypic genus Philomachus; but genetic studies support its inclusion in an enlarged Calidris. Clements, HBW, H&M and the AOU have adopted this change based on work by Gibson & Baker while IOC retains the old name. Digiscoped with Panasonic DMC-LX5 | Nikon FieldScope III | 30XWA | hand-held (no adapter).
References:
Gibson, R. & Baker, A.J. (2012) Multiple gene sequences resolve phylogenetic relationships in the shorebird suborder Scolopaci (Aves: Charadriiformes). Mol. Phyl. & Evol. 64(1): 66–72.
Rasmussen, PC & Anderton, JC (2005). Birds of South Asia. The Ripley Guide. Volume 2. Washington DC and Barcelona: Smithsonian Institution and Lynx Edicions.
Van Gils, J., Wiersma, P., Kirwan, G.M. & Garcia, E.F.J. (2016). Ruff (Calidris pugnax). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/53943 on 5 May 2016).