The theme of revenge could also be present. Maybe the murder was committed as an act of revenge for something that happened in the past. The story could then explore the motives and consequences of seeking revenge, as well as how it all ties in with the mystery of the murder.
One possible theme could be justice. Since it's a murder mystery, the search for the killer is often about bringing justice to the victim.
Well, 'The Hound of the Baskervilles' by Arthur Conan Doyle is a great mystery novel. It has a spooky atmosphere and a complex plot full of twists and turns.
The contrast between the joyous Christmas season and the dark act of murder is also a typical theme. The bright lights, presents, and celebration provide a sharp contrast to the grim nature of the crime. For example, in many such novels, the murderer may strike during a Christmas party or while the family is opening presents. It adds an element of shock and irony to the story.
Jealousy can be a big motive. For example, if one student is getting all the attention and good grades, another student might be driven to murder out of envy.
The theme of the femme fatale is quite common. A beautiful and mysterious woman may be involved, either as a victim or as the murderer herself. Another is the theme of the haunted past. The murderer's actions could be rooted in some traumatic event from their past. Also, the theme of the hidden identity is often seen. A character may not be who they seem, and this is closely related to the mystery of the murder.
Power struggles are also common. There are hierarchies and battles for dominance in the Wall Street world. A murder could be part of a power play, where someone wants to eliminate a rival to rise to the top. It could be about who controls the biggest deals or has the most influence in the financial world.
Love and aging could be a theme. Since it's an old bird, it might explore how love is different or the same in old age compared to youth.
One possible theme could be survival. If the bird catcher is in a tough situation, catching birds might be a means of survival, either for food or to trade for other necessities.
One possible theme could be isolation. If the boy is singled out by the bird in a scary way, he may feel extremely alone and cut off from the rest of the world.
Well, one possible theme could be nature and man's connection to it. Since it involves a 'bird man', it might show how humans can co - exist and interact with the natural world of birds.
Another theme could be freedom. Maybe the little bird was caged at first and then managed to escape and regain its freedom in the true story. It could show the longing for freedom that all living beings have.