Búfalos ferais na Reserva Biológica do Guaporé, RO: mapeamento e propostas de erradicação

Abstract

Impacts of feral water buffalo populations (Bubalus bubalis) have happened worldwide included Brazil. In this country the protected area of REBIO do Guaporé in the state of Rondônia (Amazon) has been affected by water buffalo. The buffalo’s introduction in this area occurred around the 1950s, when 66 animals were brought to a farm next to REBIO do Guaporé. When the farm was abandoned the Buffaloes remained unchecked, increased in number (currently estimated approx. 4.000 animals) and resulted in significant alterations in the region of the Reserve. Few steps dealt with this issue and almost nothing is known about the buffaloes of the region. This dissertation attempted mapping the area where the animals have been, as also providing proposals for the control of the population. In addition, it indicates how the likely environmental impacts of the buffaloes on the Reserve can be monitored and evaluated. For mapping of the area, three flights were conducted. The captured data from the GPS were transferred to softwares which provided a total area occupied of 49.311 ha (nearly 8% of Reserve area). From this total Area, 18.706 ha are heavily populated by buffaloes. The area used is composed predominantly of grasslands (62.5%), followed by 25.1% of forests and ecotones and 12.4% of palm forests. The presence of perennial water courses and large extensions forests, as well as aspects related to the species, contribute to the delimitation of the buffalo in one single area. The total of the occupied area in the Reserve plus the area of Pau D'Óleo farm (place of the initial introduction of the buffaloes) results a total of 60,300 ha occupied. There are different indications of environmental changes in the occupied area. Buffaloes are the main threat to the ecosystems of the Reserve. There is high dispersion potential of animals to bordering land of the occupied area. To solve that problem, two proposals are presented for the eradication of the Buffaloes. The first is the massive slaughter of animals. The second is successive rounds of sterilization. Ethical, economic and logistical aspects were evaluated. However, control measures can be adopted only if there are necessary conditions for implementation. Regardless of the decision, the buffaloes population monitoring is essential.