Continuity mistake: When Mrs. Brenner escapes the neighbor's farm after finding him dead with eyes pecked out, she is driving so fast that there is a half mile long dust storm trailing behind her pickup truck. She slides almost sideways to a stop in her yard. In the next shot she is seen bolting from the truck... with not a speck of dust stirring anywhere to be seen. (00:59:00)
Continuity mistake: Annie's position in the doorway changes between shots but Melanie's eyes stay fixed on one spot as she's speaking to her. (00:31:50)
Continuity mistake: The top magazine piled on the table to the left of Lydia is seen protruding out over the edge in front of the others. It's moved back after the birds fly out of the fireplace. (00:54:30)
Continuity mistake: In the final bird attack on the house Mitch runs to Lydia and Cathy huddled in the corner by the bookcase. The lighting has been moved and the shadow on the red books in the bookcase disappears in the next shot. (01:42:55)
Continuity mistake: As the store manager takes Melanie outside to look at Mitch's house, the dog license sign on the window of the door is reversed from when Melanie walked up. (00:13:05)
Continuity mistake: As Mitch runs to get the hammer and nails the shadow underneath the table next to the far wall changes between shots. First it's too dark to see under the table, than as Melanie watches him you can see the shadow of the table's leg against the wall. (01:43:40)
Audio problem: That is not a Martin outboard motor sound when Melanie is on the bay; it is a two-cylinder OMC outboard motor running (in neutral).
Continuity mistake: When the birds invade the house from the fireplace Melanie's hairdo is completely messed up. In the very next scene with the policeman, Melanie's hairdo is perfect. (00:55:32 - 00:56:00)
Continuity mistake: During the gulls' attack on Cathy's birthday party, Melanie sees a gull attacking a girl in a blue dress and takes her suit coat off to wave it at the gull to frighten it away. The next shot, from a distance, shows them running into the house and Melanie is wearing the coat again. A second later there's a closer shot of them running in and Melanie's coat is off again and she's carrying it.
Continuity mistake: When facing the exterior of Annie Hayworth's house, the bay window alcove to the left of the front door isn't deep enough to contain everything that we see in it when we later see it from the inside.
Other mistake: When Melanie is signing the card for Cathy on top of her car there is a brown paper bag underneath the card, she leaves it, when she drives out it's no longer there.
Revealing mistake: When hundreds of sparrows pour out of the fireplace, filling the house, they do not cast shadows on the furniture, walls or people.
Factual error: The firefighters arrive at the gas station and proceed to spray water on the fire. You cannot put out a gasoline fire with water; it requires firefighting foam. Water would only spread the fire even more.
Revealing mistake: In virtually all the outdoor attack scenes (but most noticeably in the phone booth sequence), the rotoscope seagulls and crows are proportioned about 150% to 200% of their natural size, about the size of turkeys.
Continuity mistake: As Melanie and Annie smoke their cigarettes you can see the shadow of her tree on the door post but when we saw this spot before as Melanie walked up to the house it wasn't there. (00:16:50)
Continuity mistake: Before Melanie walks up the stairs to the bedroom there's a shadow of a plant on her jacket. This is wrong because in the shot before we can see up the stairs and there's no plant with any light behind it. (01:46:50)
Continuity mistake: The shadow cast by the cage gets shorter between shots as she puts the card for Cathy up against it. (00:22:25)
Continuity mistake: As Mitch checks the doors and windows look closely at the table to the left of the brown chair on the bottom left of the screen, it has on it an ash tray very close to a plate and a silver box. The shadow of the brown chair falls on the silver box but the next time we see this table, after Lydia straightens up, the brown chair has been moved away to make room for the camera and its shadow no longer falls on the box. (01:36:50 - 01:39:10)
Visible crew/equipment: As Melanie walks into the living room a moving shadow appears where it shouldn't be, to the left of the fireplace next to the clock. (00:22:20)
Continuity mistake: Melanie cleans off all the blood on her forehead and in her hair with the Kleenex, but in the next shot there's more blood that appears in her hair than before. (00:27:20)
Answer: The movie takes place in the 1960s, so presumably gas pumps worked a bit differently back then. This is also a small town and probably the gas station had not modernized. There may not have been automatic shut-offs, or if there was, it was faulty.
raywest ★
The automatic shut off is in the handle of the hose. When a person grips the handle they have to lift a levered switch to allow gas flow; the lever is spring loaded so that if it is released the gas will stop flowing. I have looked at older antique gas pumps and they are all the same; even the visible glass gravity flow ones. If that hose was dropped the the gas should have stopped flowing.
michael g