Is this snowy building a nest?

[Dinusaur]

Today I saw this female snow owl diving into a bush and then flew back to a nearby mound clutching a bunch of twigs (see picture below). Is she trying to build a nest? Or simply thought she had grabbed a prey? After dumping these twigs on the mound and sitting there for a little while she flew away and sat on a nearby light post. Is there another explanation of her twig collection?

[Paul O'Toole]

Not nest building for sure, they only do that in there normal range during breeding season. Likely grabbed a rodent and took some grass with it.