If I'm not mistaken, the word "bird" represents individuals of both sexes. The sentence makes sence, if we say "The mail bird's tail..."
To avoid misinterpretations I would prefer: "helps attract femals" because "it" may refer to "tail".
If I'm not mistaken, the word "bird" represents individuals of both sexes. The sentence makes sence, if we say "The mail bird's tail..."
To avoid misinterpretations I would prefer: "helps attract femals" because "it" may refer to "tail".