The document discusses different ways to determine the sex of birds. It notes that the author previously thought it required surgery or extensive observation by experts to tell males and females apart. However, it states that determining the sex of birds can actually be done through examining physical traits like feathers, beak size and shape, and without much experience. Readers are then instructed to look at images of two birds on the next page to see if they can identify which is the female based on visual cues.

1. How can you determine a bird’s sex? Until now I was never able to determine which was the male and which the female.

2. I always thought that it had to be determined surgically, while ornitoligsts spoke about the feathers, the size, the beak and other equally idiotic ways that required hours upon hours of observing them in their natural habitat and so on. Until now… Of two birds, which is the female? In the next page you’ll see two birds. Study them carefully. Have a look and see if you can determine which of the two is the female. It can be done. Even by people with limited experience in birdwatching

4. Now, send this to all the men you know. And to all the women that have a great sense of humour