Blackbirds live fairly short lives with a life expectancy of only 3 years. Many blackbirds do not live past their first year because of the environment. In captivity, blackbirds are known to live up to 20 years.
Blackbirds have such a high population because of their ability to find food in almost any habitat, making it able to live in a diverse setting. Blackbirds are even known to survive in harsh winters where other birds will starve.