A 40-year-old man is appealing his 580-year prison sentence for sexually abusing six children, including two Amish girls he and his girlfriend kidnapped in northern New York last year.

The public defender for Stephen Howells filed the appeal Tuesday in U.S. District Court in Syracuse, where he and 26-year-old Nicole Vaisey were sentenced Dec. 17 for sexually abusing children ranging in age from 5 to 11 and recording the acts on video.

Vaisey was sentenced to 300 years.

The victims included two Amish sisters, ages 7 and 12, who Howells and Vaisey abducted from a roadside farm stand outside the girls' home in August 2014. The girls were released a day later.

The couple pleaded guilty in May to federal charges that included conspiracy to sexually exploit minors.