Population status and ecology of common hippopotamus (hippopotamus amphibius, linnaeus, 1758) in boye wetland, Jimma, Ethiopia, with special reference to the human and animal conflict

Abstract

A study on the population status, ecology and human conflicts of hippopotamus (Hippopotamus amphibius) was conducted in Boye wetland between February and August, 2013. Total ground count, field observations, interviews and questionnaire techniques were used to collect data. The behavioural activity and event patterns were studied with 30 minutes interval following a male and female focal individual. The average of 14.75 ± 1.89 of hippopotamus was recorded in the study area. Among them, 32.20% was males, 44.07% females and 23.73% young. However, the population composition had no statistical differences (F = 0.683, df= 2, P = 0.518). The male to female sex ratio was 1.00:1.37. But, young to adult age individual ratio was 1.00:3.21. During the rainy season, hippopotamus migrated into Gibe River. The population size of hippopotamus counted at Boye wetland and Gibe River had no significant difference (P>0.05). Resting comprise the majority of their activity with 42.50%, followed by moving 34.16%, feeding 19.63% and mating 3.71% of day time. Barking and yawning events took 51.18% and 48.82% of their time, respectively. Males spent more time in resting than females, while females were active in all behavioural activity and event patterns except mating activity. Feeding and moving peak activities were observed early in the morning and late afternoon hours with resting peak during the mid-day. Barking and yawning events were mostly increased in the afternoon. Hippopotamus consumed a total of 26 species of plants. Of these, Eriochloa fatmensis (11.68%), Typha latifolia (9.91%), Echinocloa pyramidalis (9.59%) and Cynodon dactylon (8.45%) were the top four species of plants contributing for 39.63% of their overall diet. Hippopotamus’s footprint had an average of 81.00cm circumference and 84.94cm distance of slips. Footprint circumferences and distance were positively correlated (r=0.795). Among the respondents, 47.3% had negative attitude towards hippopotamus, while 37.3% and 15.5% had positive and neutral attitudes, respectively. Conflicts with human and other anthropogenic factors influenced hippopotamus distribution in the study area. Therefore, it is recommended that prohibit the expansion of human settlements should not be encouraged in the hippopotamus habitat. Awareness creation around this local people and community participation in the conservation programme also recommended.