Complex sentence: He was also known for his dry wit, and an habit to think aloud and abruptly change subjects, in one instance he commented of another ornithologist, aged 85: I think he is beginning to get old.
Split into simpler sentences: He was also known for his dry wit and a habit of thinking aloud and abruptly changing subjects. In one instance he commented of another ornithologist, aged 85: I think he is beginning to get old.