GREGARIOUS NESTING BEHAVIOR OF THICK-BILLED PARROTS (RHYNCHOPSITTA PACHYRHYNCHA) IN ASPEN STANDS. - Monterrubio-Rico, Tiberio C.; Cruz-Nieto, Javier; Enkerlin-Hoeflich, Ernesto; Venegas-Holguin, Diana; Tellez-Garcia, Lorena; Marin-Togo, Consuelo (Wilson Journal of Ornithology, 2006)