What is the plot of "Birds" by Du Maurier?

On December 3, Nat Hocken noticed that a huge flock of birds had gathered on the beach near his home. That night, birds began to approach his home and attacked Nat and his children when they were able to enter the house. The next day, the birds were gone, but Nat and others eventually realized that the birds waited for the flood tide to resume their attack of people worldwide. Nat and his neighbors (those who believed that the birds were a threat) made the changes necessary to protect their homes and families as best they could from the murderous birds, who had succeeded in killing many.

After living in terror for some time, Nat and his family learned the patterns involved in the birds' nightly attacks. They realized that the smaller birds attacked first, followed by the larger birds. They were also very aware of the daily schedule dictated by the birds' attacks and used that awareness to their advantage and gathered food, and other necessities when the birds presented relatively little threat. In the end, Nat and his family seem to have reached the understanding that they are among some of the last survivors and are no longer overwhelmed by their circumstances, but accept their position and do their best to deal with it.