Which of these birds is known for significant sexual dimorphism?

The Kestrel is an example of a bird known for significant sexual dimorphism, meaning there is a pronounced difference in appearance between males and females of the species. In the case of Kestrels, males typically have a more vibrant plumage with a bluish-gray coloration on the wings, while females exhibit a more subdued brownish coloration, which is thought to provide better camouflage when nesting.

Sexual dimorphism can have important implications for behavior, mating rituals, and survival strategies. In many birds of prey, where the male and female may take on different roles during hunting and nesting, these differences can aid in their respective functions within a mating pair.

While the Peregrine and Gyrfalcon also exhibit some degree of sexual dimorphism, it is less pronounced compared to the Kestrel. Therefore, while the Kestrel is the most notable example among these birds in terms of significant differences in male and female appearance, the other options do not represent the same extent of sexual dimorphism evident in Kestrels.