Lots of bird action on the river this morning.

-- A goose, probably one of the family that lives up by the Sanitation garage about a mile north. They had five chicks last year.

-- The pair of bufflehads, out in the deep water they like.

-- Six mallards flying around urgently, scoping out the piers: five just arrived to join the skinny advance-duck from a few days ago.

-- A wood duck, who doesn't even live here, feeding and taking a breather on his way north.

Also lots of chirping going on in the trees, and the seagulls can't sit still. Maybe spring is coming after all.

So you bird people out there, tell me this: birds go south not because the days get shorter or colder, but because the food runs out, right? So why do they come back? If there's still lots to eat in the south, what's the mechanism that tells them it's time to go north?