United States ornithologist John Cassin, 1813-1869

This video from the USA says about itself:

Cassin’s Finch (Haemorhous cassinii) Sitting in the Snow – Colorado – April 27, 2016

From the Cornell Lab of Ornithology in the USA, 5 September 2019:

Five American Birds Are Named for Him. So Who Was John Cassin?

Carrying on the work of luminaries Alexander Wilson and John James Audubon, John Cassin described nearly 200 bird species and ushered in a new level of rigor in American ornithology. His life was cut short from years poring over specimens preserved with arsenic—but even so he became one of the most admired ornithologists of the 19th century. Ever see a Cassin’s Kingbird, Vireo, Finch, Auklet, or Sparrow? Meet John Cassin.