Range contraction in the pampas meadowlark Sturnella defilippii in the southern pampas grasslands of Argentina

por Gabelli, F.M., Fernández, G.J., Ferretti, V., Posse, G., Coconier, E., Gavieiro, H.J., Llambías, P.E., Peláez, P.I., Vallés, M.L., Tubaro, P.L.