Complex sentence: One pack reintroduced into Etosha National Park was destroyed by lions, and a population crash in lions in the Ngorongoro Crater during the 1960s resulted in an increase in African wild dog sightings, only for their numbers to decline once the lions recovered.
Split into simpler sentences: One pack reintroduced into Etosha National Park was destroyed by lions. A population crash in lions in the Ngorongoro Crater during the 1960s resulted in an increase in African wild dog sightings, only for their numbers to decline once the lions recovered.