Nutritional ecology of Asian elephant (Elephas maximus) and human-wildlife interactions : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Conservation Ecology at Massey University, Albany, New Zealand

Abstract

Reducing human-wildlife conflict has recently been recognised as an important aspect of wildlife management and represents one of the most complex challenges currently facing conservationists worldwide. Conflicts between humans and wild animals arise as a result of the loss, degradation and fragmentation of wildlife habitats through anthropogenic activities such as logging, animal husbandry, agricultural expansion and infrastructure development. Habitat fragmentation results in reduced areas of habitat and increased probability of contact between people and wild animals as the animals move in order to meet their nutritional and other ecological and behavioural requirements. Habitat degradation has led to food-related problems in populations of many species of wildlife, and the Asian elephant (Elephas maximus) is particularly vulnerable because it requires such a large amount of food per day. Large herbivores, such as elephants, are especially likely to suffer during periodic food shortages when they cannot meet their nutritional targets. Understanding the dietary and nutritional needs of elephants is crucial for managing habitats in ways that will ensure their survival, in particular by minimising conflict with humans. However, obtaining information about the dietary requirements of wild animals is difficult. This thesis investigates the diets and nutritional priorities of captive, domestic and wild elephants through the application of nutritional geometry. Initially, I examined the food intake, food composition and the resultant dietary macronutrient and fibre intake in a captive female Asian elephant. My results showed that the proportions of the elephant’s daily macronutrient and neutral detergent fibre (NDF) intake were different than the proportions in the daily mixture of provisioned foods and were consistent across days, suggesting that she was selectively feeding on available foods. Results indicated that she prioritised the ratio of protein: non-protein energy in her diet, with the ratio of nonprotein macronutrients (fats and non-structural carbohydrates) to digestible fibre (NDF) being varied so as to maintain a more constant proportion of dietary protein. Similar results in which the proportion of dietary energy contributed by protein was prioritised. This was revealed in my study on domesticated elephants, with most elephants maintaining constant proportional protein energy in their diet, but different individuals achieving this by consuming different ratios of non-protein energy (NPE) to neutral detergent fibre (NDF) energy. I also carried out a food preference survey for the wild elephants. I found that 57 species of fodder plants in 28 families were consumed by wild Asian elephants, including 13 species of grasses, five shrubs, two climbers, one herb and 36 trees. The feeding preference index further showed that browse species are preferred during the dry season, while a browse and grass combination is favoured during the rainy season. These findings were used to test the hypothesis that the elephants are selectively feeding against a null hypothesis that feeding is proportional to availability. The difference in the availability and the utilisation supports the alternative hypothesis of selective feeding to obtain the required macronutrient intake. An investigation of human-elephant conflict through a questionnaire survey showed that the depletion of natural forage inside and outside protected areas leads to an increase in elephants raiding crops because the grain-laden cultivated food plants are more palatable and more nutritious than wild browse plants. This study concluded that among the many factors, dietary requirements and selective browsing habits are believed to be the root causes in precipitating destructive behaviour in wild elephants, leading to fatal human-elephant conflict. This study also found that locally in central Nepal, crop raiding was the main cause of conflict with humans. Respondents believed that humanelephant conflict could be minimised by re-vegetating internal parklands and park boundaries with native elephant food plants. The study also showed that regional conflict intensity as measured per elephant damage was high in western Nepal; however, conflict regarding human and elephant casualties was higher in central and eastern regions. In summary, this study substantially advances our knowledge of the nutritional ecology of elephants and makes a significant contribution towards understanding the dietary and nutritional aspects of three different groups of elephants (captive, non-captive domestic and wild), as well as the nutritional drive of human-elephant conflicts. My findings have implications for the management of habitats for the conservation of Asian elephants and the mitigation of human-elephant conflict.