O potencial de algumas espécies de mamíferos e de aves como dispersores de sementes em paisagens fragmentadas do leste amazônico (região Bragantina, Pará)

Abstract

A study was conducted on the potential of some species of mammals and birds as seed dispersers, by evaluating the effect of ingesting guava (Psidium guajava L.) seeds on the germination rate and speed. The animals were kept in captivity at the Museu Paraense Emílio Goeldi, where they were provided with fruits, their feces were collected and the seeds were separated and taken to the greenhouse (27°C). It was observed that 86.25% of the seeds ingested by the agoutis (Dasyprocta prymnolopha) germinated and 81.25% of the control germinated. The opposite happened with the seeds ingested by birds, where the germination rate was low, ranging from 17.85% to 50% and the control 80.35%. The germination rates (GI) and speed coefficients (CV) of the agoutis did not differ statistically from the control. In the case of birds, the GI did not show significant difference, but the CV of the species Piriquito Rei (Aratinga aurea), Maitaca de Cabeça Azul (Pionus mestruus), Jandaia Sol (Aratinga solstitialisy, Papagaio do Mangue (Amazona amazonicai) and Papagaio da Mangueira (Brotogeris versicolurus) were statistically lower than the control. In other studies with mammals, such as the Guaribas (Alouatta belzebuti), it was observed that there was also no change in the rate and speed of germination. However, in the case of other bird species such as the Tucumaçu (Ramphastos toco) and Gralha-do-Campo (Cyanocorax cristellus) the rate and speed of seed germination increased or remained unchanged. The conclusion was reached that mammals and birds are good seed dispersers, but the speeds are different, not implying, therefore, in the alteration of their viability.