First Primroses of 2013

Front-Yard Primroses February 2013

Primroses are hardy and pretty. I like them to fill in places that grass might otherwise grow, such as around the base of our clothesline. We have a couple blooming now even though it's still February.
One question: what is nibbling on the petals and leaves? It's too cold for bugs, but I see several kinds of small birds hopping around picking at the soil. Maybe they like a little salad on the side.