Editing Chimney swift (section)

==History of observation==

In 1899, Mary Day of [[New Jersey]] observed a pair of chimney swifts nesting in a chimney, and noted the [[Egg incubation|incubation period]] was 19 days. The first detailed study of chimney swifts began in 1915 by self-taught ornithologist [[Althea Sherman]] in [[Iowa]]. She commissioned a 28 foot tall tower, of a similar design to a chimney, with ladders and peep holes installed to facilitate observation. Chimney swifts nested in her tower, and for over fifteen years, she meticulously recorded her observations, filling over 400 pages.<ref name=Kyle>{{cite book|title=Chimney Swifts: America's Mysterious Birds Above The Fireplace|author=Paul D. Kyle|publisher=Texas A & M University Press|year=2005}}</ref> Sherman remarked that although the tower had been designed with a limited knowledge of the nesting behavior of chimney swifts, after many years of observation she believed that the original design was ideal.<ref>{{cite book|title=Birds of an Iowa Dooryard|publisher=University of Iowa Press|year=1952|author=Althea Sherman|author-link=Althea Sherman}}</ref>