According to the narrator, how does Nat spend his days in the beginning of "The Birds"?

In the beginning of "The Birds," the narrator introduces Nat Hocken, a disabled veteran, and informs the reader how he spends his working day. He works for Mr Trigg, the farmer, three days per week and is given lighter tasks, like hedging and thatching. He tends to these jobs in the morning and then, at midday, Nat takes his homemade lunch and sits on the cliff's edge where he watches the birds. He watches the birds on the land and he watches those out at sea. 

He has watched the birds so regularly that he has memorised their seasonal behaviours. Autumn is the best time for bird-watching, for example, because the non-migratory birds develop a pattern of their own which interests Nat. 

On December third, however, while eating his lunch at the cliff, Nat observes a sudden change in the behaviour of the birds. Their "restless" demeanour is the most obvious change and this foreshadows the conflicts to come.