Unusual Bird: Fox Sparrow with pied leucism

I count birds for Feederwatch and spotted this Fox Sparrow on March 22 (not my count day) under the feeder. He was one four fox sparrows that day. Since then he reguarly shows up. I submitted the pictures first to Bird Studies Canada’ Kerry Wilcox who referred me to this site.
I hope you find my pictures worthwhile.

Best Regards,
Nicola Visser
Feederwatch # 92055