Chicken Anatomy: The Crop Impacted Crop and Sour Crop
Why do roosters crow in the early morning? - Quora
Frequently Asked Questions About Our Chickens
Study finds reason why roosters crow in the morning - Science & Tech - The Jakarta Post
Is the rooster, with its thuggish ways, a domestic animal?
Keeping Roosters Quietly and Responsibly - Murray McMurray Hatchery Blog
260 Gaini idei găină, păsări, păsări colorate
Why Roosters Are Important (And Crowing Makes Them Great – Get Over It!) – Rose Hill Farm
Understanding Sour Crop In Chickens