What can kill baby bluebirds in their nest?

Baby bluebirds in their nest can be vulnerable to several threats, including predation by snakes, raccoons, and larger birds like crows. Environmental factors such as severe weather, parasites, and diseases can also pose significant risks to their survival. Additionally, human-related factors like habitat destruction and pesticide use may further endanger their chances of reaching maturity. Keeping nesting sites safe and monitoring potential threats is crucial for their survival.