DEAR JOAN: Our backyard patio, which sits below our neighbor's large maple tree, is littered with black droppings from birds every year, mostly during winter months.
I imagine it is the berries the birds are eating this time of year that makes for the black droppings, but this year they are excessive. Is there a surge in bird or berry population that is making this so bad this year? Also, my concern is if the dark stains will wash away once we get some good rains.
We added nice patio furniture last fall, which luckily I got covers for, but the covers and the patio are just a mess with all the droppings. I recall in past years that they mostly wash away, but there is so much this year I'm getting concerned.
I don't think we get as many during the summer months when we are outdoors more. What's that about? Are the berries causing excessive droppings? Or is it because there aren't leaves on the trees in the winter to catch the droppings?
DEAR PRISCILLA: The droppings consist of both uric acid (the white stuff) and the food waste (the dark stuff). Birds kidneys are designed to conserve water for the body, so instead of normal urine, they produce uric acid. But it's the dark stuff that is causing the stains.
The blackness most likely is from berries. Birds eat a wide variety of food, including berries, but once things pass through the digestive system, they could come out black or purple.
The droppings themselves should wash away with a good rain or a spray from the hose, but if the birds have eaten something that stains, such as berries, it will leave a reminder. There are a few ways of deal of with that.
First, scrape off the residue, and the sooner you attack the problem, the better. In dealing with the stain, you can try using soda crystals -- sodium carbonate -- and hot water. You should be able to find the crystals at a hardware or home supply store. Look for washing soda, soda crystals, "sal soda" or water softener. Mix it with hot water and scrub away.
You also can mix liquid detergent with hot water, then soak rags in it and put them on the spots. Let them set for an hour, then use a scrub brush.
Or you can try a product called "Poop-Off," sold at pet food stores.
The bird population increases and falls with regularity, but mostly when people notice an influx it is because the birds have simply found a neighborhood they like.
The absence of leaves on the trees probably contributes to the increase in droppings, but also the days are shorter in the winter, meaning the birds come home to roost earlier and stay in the trees longer.
In the summer, people are out in their yards more, too, making that environment less attractive to birds. And just in case you're wondering, birds poop right before taking flight -- it makes them lighter. They tend to make the biggest messes before leaving the trees at dawn.
Two cats are looking for their lost owners. The first one, called Lucky by the Caltrans worker who rescued him from the ledge beneath Interstate 680 near Contra Costa Boulevard, was found Feb. 6. He has injuries but is doing well. He is white with gray and black markings. If he's yours, contact me.
The other is a young harlequin faded calico kitten with green eyes and a kink in her tail, found Jan. 31 on Full Moon Drive in the El Sobrante-Richmond area. If she's yours, call her rescuer at 510-223-1657.
Joan Morris' column runs five days a week in print and online. Contact her at firstname.lastname@example.org; or P.O. Box 8099, Walnut Creek, CA 94596.