The red head on Grupo Taca's planes have nothing to do with national birds or even Guatemala for that matter. Bear in mind that Grupo Taca is the fusion of 5 Central American Airlines from 5 Central American countries (Costa Rica, Nicaragua, Guatemala, Honduras, El Salvador). Therefore they have 5 Parakeets (Macaws if I'm not mistaking...Any ornotologists out there???) on the tails of their planes and therefore they have the red head!!! I love their color scheme and the red head!!! It looks awesome on the B767, A300 (Cargo) A320, A319, 737-200, ATR42 and Cessna Caravans!!!
The parakeet idea was originally chosen from Taca Airlines and multiplied by 5 since it's a usual sight in all these countries...
BTW: Now there are also TACA Peru planes flying for Grupo Taca now...(A319's)
Look out for Grupo Taca Mr. Federico Bloch has big visions for the airline!!!!