Influence of Agriculture on theResilience and Trophic Cascade ina Savanna Bird Community of theSerengeti Ecosystem, Tanzania

Abstract

Agriculture is one of the factors contributing to the global depletion of natural resources. Human activities such as overgrazing, deforestation, bush fires, mining, urbanization and cultivation as well as climate change have aggravated the ability of bird species to disperse into new habitat. This study investigated how agriculture altered the bird community in the Serengeti National Park. This park is structured along a rainfall gradient with highest rainfall in agricultural land northwest of the Serengeti National Park and lowest rainfall on the treeless plains in the southeast of Serengeti National Park. With respect to trophic level in agriculture there was a greater proportional decrease of species (compared to savanna) at the predator trophic level (vertebrate feeders) than at the insectivore and herbivore trophic levels. Therefore, higher feeding levels were less able to tolerate change in habitat structure due to agriculture than species at lower feeding levels.