Male cowbirds sing a variety of types of songs, demonstrating a wide range of vocal capabilities. Basing their judgment on the fact that different local populations of cowbirds of the same species sing in styles particular to their populations, ornithologists have concluded that the cowbirds' singing styles are culturally acquired, rather than genetically transmitted.
Which of the following, if true, would most strengthen the conclusion drawn by the ornithologists?
【选项】
Younger cowbirds are not proficient at singing and have been observed watching their mothers sing for years before themselves starting to sing.
选项是否正确？