137 SHORT COMMUNICATIONS ORNITOLOGIA NEOTROPICAL 19: 137–142, 2008 © The Neotropical Ornithological Society NOTES ON BIRDS THAT FOLLOW ARMY ANTS IN THE NORTHERN ANDES Margarita Rios 1,3 , Gustavo Londoño 1,4 , & Luis Biancucci 2 1 Fundación EcoAndina, Programa Colombia de Wildlife Conservation Society, Apartado Aéreo 25527, Cali, Colombia. 2 Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, Montana 59812, USA. E-mail: luis.biancucci@gmail.com Nota sobre las aves que siguen hormigas legionarias en los Andes del norte. Key words: Army ants, Labidus praedator, birds, specialized, opportunistic. Army ants flush small arthropods, which are important source of food for Neotropical birds (Willis & Oniki 1978, Swartz 2001). In Neotropical forests, there are two army ant species that are most often followed by birds: Eciton burchelli and Labidus praedator (Coates- Estrada & Estrada 1989, Swartz 2001). These two species have different activity patterns and life cycles (see below; Swartz 2001, Will- son 2004). Such differences might play an important role in shaping the ecological rela- tionships between birds and army ants. In addition, E. burchelli and L. praedator have different distributions in tropical forests _____________ 3 Current address: Instituto de Ecología, Universidad Autónoma de México. A. P. 70-275, México 04510, D.F., México. E-mail: gmargaritarios @gmail.com 4 Current address: Department of Zoology and Flo- rida Museum of Natural History, University of Florida, Gainesville, FL 32611-8525, USA. E-mail: galondo@ufl.edu (Willson 2004). Both ant species inhabit low- land forests, but only L. praedator is found in highland forests (Hilty 1974, Willson 2004). Birds vary in their dependence upon the ants for prey, ranging from occasional or irregular to obligate or specialist followers (Willis & Oniki 1978). Birds that specialize in following army ants are found primarily in lowland forests (Dobbs & Martin 1998), and have been studied extensively (Willis 1968, 1969, 1986a, 1986b; Gochfeld & Tudor 1978, Coates-Estrada & Estrada 1989, Willson 2004). Specialist refers to army ant followers that depend on army ants to flush the major- ity of their food and that are most often found with army ants (Swartz 2001). In high- land forests, however, no specialist ant fol- lowers have been identified. Highland birds that follow army ants are thought to do so only opportunistically (Vallely 2001). Rela- tively few studies have been carried out in highland forests (Hilty 1974, Gochfeld & Tudor 1978, Vallely 2001). Here we present