Why were the high concentrations of DDT in the birds bodies?

because chlorinated hydrocarbons accumulate in fatty tissues, when a ton of contaminated fishes is turned into 200 pounds of seabirds, most of the DDT from the numerous fishes ends up in relatively few birds. As a result, the birds have a higher level of contamination per pound than the fishes.

btw :

stay safe! :3

the answer is yes, they are born/created, then they grow to their limit then produce offspring, then die.