Bird Genders

This slideshow provides several examples of Iowa bird species with pictures of both genders for each species.

• Why do some species have males and females that look different and some not?

• What causes certain individuals to develop different characteristics over time?

Students could:

• Review the slides and have students guess which birds are male and which are female. 
• Conduct investigations about competition to reinforce the idea that sexual selection is driven by competition within populations. 

• The Cornell Lab | All About Birds: This a web unit students can go through and explore fancy males and the different ways they can be fancy. There are some great videos. It is very explanatory so I would save this as an extension or until later in the unit.
• The Cornell Lab | All About Birds: Why do female Belted Kingfishers have an extra rust-colored “belt” that the males don’t have?: Interesting article on origins of “pretty” females in Belted Kingfishers. Could be used to address questions on why some species have females that are more attractive.