Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
This is a prequel to the four Hunger Games movies (starring Jennifer Lawrence) which chronicled with a televised competition in which teenagers from each of 12 districts fight to the death until only one is left alive. It's the origin story of Coriolanus Snow (Donald Sutherland's character) more than 60 years before he became the tyrannical president of the country of Panem. As you would expect from the title, there are several snake scenes in the movie.
Coriolanus Snow (Tom Boyth) is assigned to mentor a girl from the poorest district named Lucy Baird (Rachel Zegler) who was selected to represent her district in the Hunger Games. She's a singer in a traveling band - the songbird of the title, and they become romantically involved.
We first see Lucy at the District 12 selection ceremony. As she walks up to the stage, we see her holding a snake behind her back that she puts down the back of the dress of a rival girl who used her important father's influence to make Lucy get selected. The girl screams and falls to the ground as the snake falls out the bottom of her dress. The girl's father slaps Lucy who sings a protest song. All of this was viewed by the television audience. Later, when Lucy is kept behind bars with the other contestants, a young girl asks her where she got the snake. Lucy tells her the snake found her and must have been a music lover because her singing calmed it down.
The next snake scene is in the laboratory of Dr. Volumnia Gaul (Viola Davis) who is in charge of the Hunger Games. When Coriolanus and his classmate Clemensia Dovecote (Ashley Liao) go to the lab we see a large glass tank full of multi-colored snakes. When Clemensia lies and takes credit for a proposal to change the games that was actually written by Coriolanus, Dr. Gaul tells her the proposal is in the terrarium. We see a piece of paper in with the snakes. Gaul tells Clemensia to reach in and take it out of the cage but not to worry because the snakes will leave her alone if they know her scent from the document, but if she's lying they'll attack her. Clemensia puts her hand in the tank and a snake immediately bites her. She falls to the floor and a woman comes and injects her with antivenin then some men drag her away. This scene is setting us up for the next snake scene, teaching us that the snakes are killers but if they recognize someone's scent, they will not attack.
In the next snake scene we see some people in Gaul's laboratory moving the giant tank full of snakes outside the lab. Coriolanus sneaks over to the tank and puts a handkerchief with Lucy's scent on it inside the snake tank. He knows the snakes will be put in the Hunger Games arena and he's making sure the snakes won't harm Lucy. Then we see the tank picked up by a helicopter and dropped into the arena where the Hunger Games are taking place. A terrorist bomb destroyed parts of the arena but the games are still taking place in the ruins. The tank breaks open and the snakes pour out, swarming over and killing the remaining contestants. When the snakes get to Lucy, they surround her but don't kill her. We see her still alive on the television screen with snakes crawling over her, the winner of the contest.
When Gaul finds the handkerchief and learns that Coriolanus rigged the games for Lucy, he is sent away to become a soldier. He bribes someone to send him to Lucy's District, number 12.
Back in District 12 we see Lucy and her friends swimming in a lake. Then we see Lucy with another girl, her holding a snake in her hand.
After
Coriolanus turns in a good friend for working with the rebels, and he is hanged for it, and then they have a fight about their future, Lucy realizes that Coriolanus is a bad person and runs away from him. He goes to search for her and sees a shawl that he gave her on the ground. When he lifts the shawl, a snake jumps out and bites him on the arm. He pulls the snake off his arm and throws it away and falls to the ground. He screams to Lucy "Is that poisonous? Are you trying to kill me?" Then he sees Lucy and shoots at her, but misses. Later when he is being transferred to another district, we learn that he survived the snake bite with help from the military medics.
The first scene, with the snake put down a girl's dress is completely believable, and something I actually saw in grade school. The snake we see appears to be a real live snake, but I'm not sure what species it is. The snake Lucy is holding later at the lake in District 12 is also a real live snake, a species of harmless Milk Snake, common in the pet trade.
The giant glass tank full of multi-colored weaponized snakes is the usual ugly pile of badly-drawn badly-rendered CGI snakes that we've become used to seeing in movies. The travesty gets even worse when they release the snakes in the arena and they become a murky pile of garbage. I know I'm a snake snob, but I can't imagine for a minute that the audience, even those terrified of snakes, believes for even a second that they are watching real snakes. Releasing thousands of snakes to kill people in an arena is absolutely absurd, especially with the even more absurd explanation that the snakes won't hurt someone whose scent they know. (How could the snakes at the top and the bottom of the tank even smell the scent?) Unfortunately, they keep repeating this absurdity because movies like this one have taught the audience that snakes are basically insentient killing machines and not living breathing animals. I was wondering whose job it was to feed the tank full of snakes and worse, clean up their mess from the bottom of the tank. I guess that's what interns are for...