Ground-Tyrants are a group of neotropical flycatchers (Tyrannidae) which tend to stand upright while foraging on or near the ground. These larger, gray birds resident on the Falkland's are of the nominate race. A smaller and browner migratory race, M. m. mentalis is found on the South American mainland. Canon PowerShot SX50 HS
References:
Farnsworth, A., Langham, G. & de Juana, E. (2018). Dark-faced Ground-tyrant (Muscisaxicola maclovianus). 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 https://www.hbw.com/node/57445 on 12 May 2018).
Jarmillo, A. (2003). Birds of Chile. Princeton Univ. Press. Princeton.