It comprises a review article and eight primary studies addressing a variety of pigmentation systems in domestic, model and wild species of birds, mammals and fish. The cover features an assortment of pigmented bird eggs laid by diverse species from around the world. Egg specimens are from the Cornelis J. Marinkelle Oological Collection--Instituto Humboldt (IAVH-CJM), Villa de Leyva, Colombia. Photo by David Ocampo (Princeton University, NJ, USA).