Moustachioed junco nest-building

That moustache doesn't help me know if this is a he-junco or a she-junco. (I'm assuming their pair is a he/she one!)

For the past couple of cold wet days, the couple has been gathering dried grass and bringing it to a spot underneath some goutweed leaves on our lawn, making a nest there. It seems a dangerous, wide-open spot. Usually the juncos around our house make their nests under the metre-high clumps of yew bushes and the like. But, there you go: it's their choice, iddinit?

After they gather their grass moustaches, they fly up to this branch or near-by, to survey the scene before they dive down to their secret walkway under the goutweed.

When I took this picture this morning, it was three degrees above freezing, and raining. Unpleasant weather to be out in, but it wasn't stopping them from their construction work.