[1] Alfred Otto Gross was born on April 8, 1883, in Atwood, Illinois, as the youngest of nine children to Henry, a merchant, and Sophia, both immigrants from Kadelburg, Germany.
He was one of the earliest practitioners of using binoculars in the field, and with an assistant he surveyed more than 3,000 miles of land across Illinois, using walking transects of 50 yards width, making the first attempts of any US state to estimate bird populations.
With his friend, James L. Peters, Gross birdwatched the local areas around him, including Mount Auburn, Middlesex Fells, and Fresh Pond.
Much of his work was centered around his fieldwork in two Arctic expeditions led by Donald B. MacMillan in 1934 and 1937, and the study of the remaining heath hens at Martha's Vineyard, Massachusetts in the late 1920s and early 1930s.
[1] He was the first director of Bowdoin College's Scientific Station located on Kent Island, in New Brunswick from 1936 until his retirement, and collected footage of the birds there.
He produced a silent film on the subject, The Heath Hen, to educate the viewers on the important role of the fragile bird populations he studied.
[citation needed] The Gross films displayed the final moments of the last heath hen, and it was the first species whose extinction was witnessed firsthand through a digital medium.