| Time Period | Major Causative Event | Consequences |
| Before 1972 (the reign of Emperor Hailesellassie) | Immigration of the Ittu to Kereyou’s land | Population Increment around Kereyou settlements |
| Complaint of the community to the Emperor | Compensation of 600 “Gasha” (250 km2) of land | |
| “No man’s land” land tenure system (land belongs to the land lord) | Land alienation and expropriation of land for non-pastoral activities | |
| Between 1972 & 1986 (the “Derg” regime) | Boundary demarcation of ANP by the Derg | Enmity between the local communities and park workers |
| High poaching by Derge soldiers and Argoba people | Reduction of large mammal population | |
| Drought (1975/76) | Permission of grazing land, settlement and borehole construction inside the ANP | |
| Increased immigration of Ittu | Migration of the Kereyou toward the park | |
| Civil war and conflict | Less attention from the government and the loss of human lives and looting of livestock | |
| The 1975 land reform in principle granted pastoralists right to grazing land | Didn’t improve the land right position of pastoralists | |
| Between 1986 & 2006 (the present government (EPDRF)) | Expansion of government and private farms | Land alienation and pastoralists moved into the ANP |
| Excessive overstocking | Low forage yield and further expansion into the ANP | |
| High conflict | Insecurity became high and communities moved further into the ANP | |
| Infrastructure development (road and railway) | Killing of animals increased | |
| Expansion of sedentrization and agro-pastoralist way of life | High demand for firewood, charcoal and house construction | |
| Establishment of several institutional arrangements | In principle official recognition of the pastoral production system |