Estudo da distribuição e movimento de elefantes e seu impacto nas machambas adjacentes à Reserva Especial de Maputo

Abstract

This study was carried out between January 1996 and March 1997. It aimed to study elephant movements within and adjacent to the Reserve; to determine the density of elephants in different habitats and relate this to the vegetation and the salinity of water available in and around the Reserve; and to estimate the destruction being done by elephants on adjacent farms. To study elephant movement, a young female elephant was monitored for a period of four months (between May and August 1996) using a collar containing a UHF satellite transmitter. The relative density of elephants in the plant communities in this Reserve was estimated by the elephant faecal bolus counting method. The salinity of water from major sources was determined twice; in the rainy season and in the dry season. To determine the percentage of destruction on fields adjacent to the Game Reserve by elephants, a survey was conducted beforehand. The fields of all farmers who responded positively to the surveys were surveyed, the cultivated area measured, the area destroyed by elephants and the crops grown on them recorded. At the same time, a survey was conducted to find out the methods used by farmers to drive elephants away; the efficiency of these methods as well as those proposed by them to mitigate conflicts. On the other hand, a record card of incursions was distributed in all areas. During the four months of the study, the elephant monitored by satellite frequently used the north-eastern part of the Reserve, and a stay area (Minimum Convex Polygon) of 129 Km2 was observed, and a significant preference for low and open forests. High and low brine as well as grassland were less preferred. Minimum velocity was equal during day and night as well as in the five vegetation communities used. No significant differences were observed between elephant location classes during day and night as well as in the five vegetation communities. No significant differences were found between elephant density in the wet and dry seasons. Faecal density varied between habitats, suggesting a higher preference for dry forest. Grassland was least preferred. Mean elephant density in the Reserve was 1.8 elephants/Km2 in an area of about half a square kilometre. The salinity of the studied sources ranged from 0 - 93.7%& However, no significant differences were found between the salinity of these sources in the two seasons. A significant positive correlation was observed between water salinity in the two seasons. The distribution of elephants was significantly related to water salinity. Foraging occurred throughout the year with peaks between March-April and September-October and was correlated with cultural stages. Massuane and Futi recorded highest Average Incursion Frequency throughout the year. Cassava, maize and pumpkin were the most preferred crops for elephants. The weighted average damage in the area studied was 22%> which means that each family living in the four areas covered by the study, lost on average about 85Kg of various products equivalent to 100 thousand meticais in January 1996 alone. In total, about 14 million meticais were lost. All the respondents use fatas rattles to scare the elephants away. However, this method is not efficient. 81% of them proposed electric fencing to reduce conflicts with elephants. These results suggest that the movement and distribution of elephants in the Reserve is governed by human activity, food quality and water quality. The extent of elephant damage is significant considering the size of the fields, the losses and the maximum yields obtained by farmers. The construction of an electric fence along the entire western boundary should be considered after consultation with local communities. However, it is worth in the short term to implement zoning programmes, taking into consideration a greater participation of local people in decision making to reduce conflicts between them and the Reserve.