ECOLOGY. For the article “Magnetic alignment in grazing and resting cattle and deer,” by Sabine Begall, Jaroslav Červený, Julia Neef, Oldřich Vojtěch, and Hynek Burda, which appeared in issue 36, September 9, 2008, of Proc Natl Acad Sci USA (105:13451–13455; first published August 25, 2008; 10.1073/pnas.0803650105), the authors note that due to a printer's error, on page 13454, right column, in Analysis of Body Position of Deer (Field Observation), the first sentence, “Body position of 2,974 deer (in 227 localities) was recorded in the Czech Republic” should instead read: “Body position of 2,974 deer (in 241 localities) was recorded in the Czech Republic.” Additionally, on page 13455, right column, in Sun Position and Roe Deer Orientation, the first sentence “The position of the sun could be deviated by the exact time of the day” should instead read: “The position of the sun could be determined by the exact time of the day.”