Insect abundance and food intake by agama mwanzae in Serengeti national park, Tanzania

Abstract

The kopjes of Serengeti National Park, can be considered to be an understudied ecosystem although harbours a diverse distinct flora and fauna; even basic information such as knowledge about the food of Agama mwanzae is unknown. Thus, the study involved the investigation of the spatial and seasonal variation of insect abundance and agama food intake in the grass plain kopjes of Serengeti National Park. The insects were sampled by pitfall, sweep net and tray traps monthly within one year. A total of 58 175 individuals from 16 orders were collected. The most common orders were Hymenoptera (30.19%), Hemiptera (19.50%), Orthoptera (18.10%), Diptera (10.60%), Coleoptera (9.20%), Arachnida (4.40%), Dictyoptera (2.70%), Lepidoptera (2.50%), and Isoptera (1.90%). Insect abundance was higher during the wet period as compared to the dry season and Gol kopjes attained the highest insect abundance followed by Simba and lastly Barafu kopjes. A total of 2350 insect food items were identified from 120 agama lizard specimens whereby 1597 were found during the wet season and 750 in the dry season. The majority of the diet consisted of the Hymenoptera (47.03%), Isoptera (29.78%), Coleoptera (18.29%), and Orthoptera (2.63%). In addition to insects, A. mwanzae fed on plant materials. Insects comprised the majority of food items during the wet period when this prey was most common. During the dry season plant material was the dominant food type to agama lizards because of scarcity of insect food. It was found that there was statistical significant difference in agama food intake between seasons and locations. Due to the increase of destruction of agama lizard habitats the management authorities should ensure that the land management practices should not damage these fragile habitats.