Complex sentence: However, the Grenadan Euler's Flycatcher ("L. e. flaviventris") went extinct in the early 1950s for reasons insufficiently known, but probably related to habitat destruction and possibly introduced predators.
Split into simpler sentences: However, the Grenadan Euler's Flycatcher ("L. e. flaviventris") has not been recorded since the early 1950s, and is likely extinct. The reasons for this are insufficiently known, but probably related to habitat destruction and possibly introduced predators.