The Birds
On the apocalyptic ending, political subtexts in the diner scene, and the surprising parallel between birthday surprises and bird attacks.
I would love to look at the apocalyptic ending of The Birds by referring back to two scenes earlier in the film, one that is more in the political and serious context, and the other one on a more playful note. The key question at the surface level is whether the birds will attack again, and if so, what could be the reason of attack? I think referring back to how people in town discussed it and the concept of "surprise" would be helpful in interpreting the ending.
Firstly, earlier in the film, after Melanie reported the school incident to her father, we saw a sequence of different people in the diner who had different opinions about the bird attack. The old lady who is a bird enthusiast maintained that birds would not attack for no reason; a drunk alcoholic claimed this is the end of the world; another man thought they should just shoot up the birds. There are definitely much deeper political subtext (the pacifist; the pragmatists; the pessimists; the warmongers) that we can dive into more, but what could be sure is that none of these arguments hold true before they witnessed the attack. But even after the incidents, the hostility emerges not against the birds, but rather against Melanie. We could say that the reason behind the bird attack is a McGuffin in this film, but what really matters is how characters' behaviors are catalyzed and driven by these incidents. I think maybe the message at the end of the film is not so much about the potential future attack, but rather a sense of exclusion and opposition that were never resolved and will continue.
Secondly, I kept connecting the unknown surprise attack from the birds with the event of Cathy's birthday that was one of the narrative threads in the first half of the film. When Melanie just arrived in the town, she mainly asked the post office staff two questions: one about the surprise way leading to Brenner house, and the other question on the exact name of Mitch's sister. I found that the contrast or tension between the desire of knowing the exact details and the efforts of producing a surprise has an underlying connection with the surprise nature of the bird attack. And the human desire of planning surprises occurred again when Cathy told Melanie exactly how her "surprise" birthday party would be like. In contrast, the mysterious nature and the birds could not be understood by humans. The surprises by humans and nature presented is a really powerful foil theme pair.