Uso de hábitat y coexistencia de Penelope perspicax y Ortalis columbiana (Cracidae) en la Reserva Nacional Forestal Bosque de Yotoco (Bosque subandino), valle del río Cauca, Colombia

Abstract

Population size is mainly determined by the inter-specific interactions, in addition to the productivity of the system. Both determinants are affected by the disturbances to which a landscape is subjected. In the Cauca river valley, the reduction of natural vegetation cover has been more than 90% and currently there are only a few forest remnants within which is the Yotoco reserve with 559 ha. Two species of cracids, Penelope perspicax and Ortalis columbiana, are sympatric in the reserve. After having estimated population densities for both species and which resulted in differential encounter rates between the sampling units, the use of space was evaluated with co-occurrence models, evenness, dispersion and overlap indices. The sampling design was established with 32 sampling units that were visited 14 times. The analysis of the area used was done using maximum likelihood methods in the RPresence package of the R project with the model for two species one season. Evenness and dispersion were estimated on the Vegan package. O. columbiana uses less reserve area (0.59) than P. perspicax (0.91). The dispersion for Ortalis records is aggregated, while for Penelope it is random. Similarly, Ortalis's use of space is less equitable (0.25) than Penelope's. The probability of occupation of O. columbiana when P. perspicax is present decreases from 1 to 0.55. Management plans, even for areas, are usually oriented to focal species, in this regard, it is necessary to consider the interactions between species, when actions are formulated that may favor some, but affect others.