DEAR JOAN: In contrast to the reader who complained earlier this summer of having few if any hummingbirds returning to her feeders, I have had to increase my usual two 8-ounce feeders to five, filled twice a day for a food line of well over 100 birds.

My guess is this has been brought about by the drought and a lack of natural food supply. I had both Anna's and Allen's hummingbirds visit in large numbers, but also many others, some of which I cannot identify.

I understand the Anna's will tend to remain in our area if there is a food supply, but others will migrate. In order not to create a hummer winter-resident population similar to the goose problems at Vasona Park and Shoreline, what would be the best way -- if any -- to urge the migratory species to do so, yet still let the Anna's know they are welcome to stay the winter?

Hungry hummers.
Hungry hummers. (Courtesy of Joe Brennan)

Will the cooler weather and naturally shortening days be enough to trigger the migratory calling even though a stable, artificial food source remains?

Samantha Willis

Los Altos Hills

DEAR SAMANTHA: Research has shown that keeping hummingbird feeders filled year-round doesn't hinder migration. It actually helps it.

Hummers that migrate return to their breeding grounds year after year, to the exact same place. Nothing will deter them, which is why it's important to keep those feeders full, especially this year.


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The drought and the offseason rains are playing havoc with the native plants that many hummers rely on as they make their treks across the area. Some plants bloomed earlier than usual, others didn't bloom at all, and some bloomed later. The insect population, which is a main source of protein for hummers, also has been thrown out of kilter by the same factors. The hummers, however, kept to their schedule, meaning that on the migration south, they may not have found their typical food supplies, and they probably won't find them on their journey back.

Many of the birds you have been feeding likely arrived in the area nearly starved. They will need be looking for supplemental food sources as they make their journey back to their breeding grounds. The year-round hummers also are finding fewer natural sources of food and will appreciate those backyard feeders through the winters.

To learn more about those unknown visitors, you might want to pick up a copy of "Hummingbirds: A Life-size Guide to Every Species" (Harper Design, $29.99) by Michael Fogden, Marianne Taylor and Sheri L. Williamson. The book has profiles of all 338 known species. Pair it with a Bay Area-centric guide to narrow the focus.

DEAR JOAN: My yard has numerous wild plums around the borders. This time of year the plums have long been eaten or fallen to the ground. Each morning I find four to six plum pits in the birdbath. I suppose something is trying too soak them soft to get at the kernel inside. Do you have any idea what kind of bird or critter would do this?

Dick McCall

Woodside

DEAR DICK: Whenever strange things happen in the backyard, there's usually a raccoon involved.

In this case, however, I'd look to the skies for an answer. I think your plum dipper is a crow or perhaps a scrub jay. They are known for using birdbaths in unusual ways.

Contact Joan Morris at jmorris@bayareanewsgroup.com. Read the Animal Life blog at blogs.mercurynews.com/pets.