We rarely get to see the snowy owl when it moults. Normally in August the owl is far away from Ottawa and on its breeding grounds in the Artic.

Link to study on snowy owl moulting.
https://www.uqar.ca/uqar/recherche/unites_de_recherche/chaire_biodiversite_nordique/publications/2017_robillard_et_al._jab.pdf