One of the characters, Frank Norris, is named after the author whose book this film took inspiration from.
This film uses the characters and themes from Frank Norris's novel McTeague.
The caged bird is a Lady Gould's Finch from Australia. The average lifespan under ideal conditions is about 8 years. Long lived well cared for ones may live for 10 years. But kept the way this one is 6 years would be very long. So it interferes with the time line.