House finch (Haemorhous mexicanus), Florissant Fossil Beds National Monument, 2016.

American rosefinches form the genus Haemorhous. This includes Cassin's finch (H. cassinii), the purple finch (H. purpureus) and the house finch (H. mexicanus). Identify the house finch by its streaked flank feathers and sometimes, its streaked breast and belly feathers. Usually the adult male has reddish head, neck and shoulder plumage; color intensity varies with seasons and an individual's diet. As you probably guessed from this photo, these birds are usually permanent residents in their range, which has grown from Mexico and the SW United States to include most of the contiguous US as well as Hawaii. It was introduced to Hawaii as early as 1870 and then later, illegally sold in NYC in the 1940s. Unfortunately, both vendors and owners released their house finches to avoid prosecution. The house finch easily adapted and spread through much of the country's unforested lands, displacing native purple finches and even the non-native house sparrow.