Andy/Andy
We're just back from an effort at a "Best of Argentina Birding" trip that went exceedingly well.
I need to sort out photos, lists and follow ups with our local hosts and guides now the laundry has been done but I can probably offer some suggestions and local contacts in the coming days/weeks.
Our itinerary, developed with/by our local contact, Marcelo Gavensky, who we met on our previous visit to BA, was:
Fly into BA
Day to settle in
Night Coach to Mercedes (Corrientes)
transfer to Colonia Pellegrini - Ibera birding
transfer to Estancia Virocay, NE Corrientes - grassland/wetland birding
Misiones - La Araucaria PP, Cruce Caballero PP, Urugua PP, Iguazu NP and Falls, Karadya private reserve, Surucua private reserve.
Flight to Salta then transfer to Ecoportal de Piedra (nr Palma Sol, Jujuy)
Birding around local area nr Santa Barbara Mountains
Calilegua NP, Potrero de Yala PP, Tilcara, Abra Pampa, Yavi
Drive back to Jujuy and flight to BA then Trelew
Punta Tombo, Puerto Madryn, Las Grutas, San Antonio Bay, Cerro Banderita, El Jahuel, El Condor, Rio Negro Valley, Valdes Peninsula
I'll be able to fill that out a bit when I've got more time. BA and local day trips were done 2 years ago, as was Tierra del Fuego.
Timing off the trip was based on seeing the endemics and local breeders and it worked for the birding. The Southern Right Whales (lots of pics from shore and boat) were still off Puerto Madryn (mainly mothers and calves) and the Orcas are off Valdes Peninsula but we didn't see them - you need high tide and Elephant Seal pups, we had the seals but not the tide timing.