The UCM Bird collection numbers over 12,000 specimens and document changes in biodiversity over the last 200 years. With global coverage and strengths in Colorado avifauna, the collection dates from the early 1800s to the present. Nearly 6,000 specimens were donated by the Colorado College Museum in Colorado Springs in the 1960s. This material includes the collection of Charles E. Aiken, a pioneer ornithologist in Colorado, and dates back to 1805. The Bird collection is also home to several specimens of iconic extinct species such as Passenger Pigeons and Carolina Parakeets.