Raven takes over yard's 2 birdbaths

We have two birdbaths in our backyard, referred to as the lower spa and the upper spa. In the past, they've both been very popular with all the little birds in the yard. Lately, a rather large raven has taken to flying by several times a day and soaking a cracker or biscuit in the water, softening it so he could eat it.

He prefers the upper bath but uses the lower one regularly as well. Aside from making the water very cloudy, we've seen nary a chickadee, bushtit, finch or goldfinch in the baths since he began his culinary exploits.

Currently we've de-commissioned the lower bath and are putting a lower level of water in the upper (he likes to immerse the cracker completely), and we hope he'll find another source of water. We do see him flying by daily still.

Any suggestions as to how to discourage him from our yard? Are ravens put off by the “dead crow” maneuver?

— Michael Babcock,

Oakland

DEAR MICHAEL >> Ravens and crows are closely related, both belonging to the Corvus genus of the Corvidae family of birds. What works for the crows will work for the ravens.

While I've had many readers tell me hanging a fake dead crow in the yard has worked like magic, I've had a couple of others that said their crows just weren't buying it. For those who don't know what we're talking about, hanging a fake crow in a prominent place in your yard has been known to drive the crows — and ravens — away.

The theory is that crows and ravens, being exceptionally smart, see the “dead” bird and think there must be something terribly wrong and dangerous in this yard.

To avoid ending up the same way, they abandon the area. If you try this method, it's important that you put the fake bird out under cover of darkness so the birds don't see you doing it.

If you're OK with having the raven claim one bath for its own, you should place the crow effigy near the bath you want to reserve for the other birds.

DEAR JOAN >> Recently, I found a bird nest on the driveway and the remnants of four eggs that had fallen on the cement. There was a bit of a breeze, but the nest was in a very protected place, under the eaves on a beam that holds up the porch roof.

The splatter of the eggs and the bits of shell are about 2 feet from each other. I have not seen predatory birds in the front of the house where the nest was, but there are many crows in the neighborhood.

What do you think was the reason for the nest disaster? — Paul Boehm, San Jose

DEAR PAUL >> Without more evidence, it's hard to say with any confidence exactly what happened to your nest.

Because the nest remained intact, my best guess is that an animal — a roof rat or a squirrel accidentally knocked the nest off as it ran along the beam.

Although crows and jays are known for nest robbing, the placement of the nest makes it less likely they could get at it. However, because of their checkered past, it's a possibility.

Another possibility is a raccoon, trying to get to the eggs, took down the entire nest.