Did hummingbird abandon her recently hatched babies?

DEAR JOAN >> A mama hummingbird that built a nest in our yard has disappeared. We haven’t seen her feeding the babies for several days.

Is it common for hummers to abandon their babies? One possibility is a cat may have taken the mother. We have several strays in the neighborhood. This makes us feel terrible that those poor little hummers will starve to death.

Would too much human activity (the mailman, UPS and FedEx delivery drivers) scare the mama away? That human activity didn’t prevent the mama from making her nest there, or scare her away while tending the eggs and doing first days of feeding them. It’s a mystery. Can you shed some light on this?

— Chuck and Betse, San Jose

DEAR CHUCK >> I want to let readers know that when I first got your question, I contacted you with some suggestions on wildlife rehabilitation centers nearby for you to call for help and advice. I think your experience will be helpful for other would-be bird rescuers.

Wildlife Center of Silicon Valley asked you some very important questions, and it turns out the mother had not disappeared and the babies were thriving.

Hummingbirds are among the most cautious of parents, working hard to keep predators from finding nests. After the eggs hatch, mom stays on the nest about 10 days to keep the babies warm, but once they’ve got a few ounces and some feathers on them, she keeps her distance, staying nearby and making quick trips in to feed her young. For their protection, she never lingers.

If humans aren’t watching the nest all day, they’ll likely never see that and worry something has happened to the mom.

It’s good to be alert and help, but often we rush in where we aren’t needed or wanted. Before rescuing any creature, make sure, as you did, that they really need saving. Thankfully, this pair of hummingbird babies will soon leave the nest and help fill the skies with beauty.

And don’t worry, activity around the nest shouldn’t drive a mother away from her babies.

DEAR JOAN >> Will you please check with your cat experts about large cats not purring, which you mentioned in your Monday column? At the zoo sometime back I heard a large cat, I think a leopard, purring.

— Francie Wise, Bay Area

DEAR FRANCE >> There is some debate on whether the smaller of the big cats can actually purr. The entire cat world once was divided between the purrers and non-purrers, all based on a single bone in the throat known as the hyoid bone.

In housecats, the hyoid bone is ossified and rigid, so when the cat’s larynx vibrates, the hyoid bone resonates and produces what we recognize as the purr. The hyoid in cougars, bobcats, lynxes and cheetahs also is ossified, so experts put them in the purring family. In the big cats — lions and tigers — the hyoid bone is only partially ossified, so no purr.

Over time experts began to question whether those wild cats actually are producing a purr, or if they’re making other grumbling sounds that imitate a purr but is not technically a purr.