DEAR JOAN: We enjoyed your story about Annie, the peregrine falcon that lives on the Cal bell tower, and it sparked a discussion about how old Annie is and how long she can keep laying eggs.
We started wondering if birds go through menopause. We know that chickens stop laying after a couple of years, but how long will Annie continue to hatch chicks?
— Jack R., San Mateo
DEAR JACK: First, an update on Annie, who has lost several mates, including her first, Grinnell. Another male has entered Annie’s life, and the early stages of courtship have begun. Until the relationship is on solid ground, we’re just calling him the New Guy.
As long as Annie stays healthy, she will continue to lay eggs through to the end of her life.
Menopause in mammals is an interesting phenomenon. Humans go through menopause, but only four other mammals are known to experience it as well. Surprisingly, it’s not chimps and apes that we share the trait with, but marine mammals – orcas, short-finned pilot whales, beluga whales and narwhals.
While primates can lose their fertility, they do so at the end of their lives, dying shortly afterward. Mammals that go through menopause live many years after they lose the ability to reproduce.
Scientists believe it’s related to something called the grandmother hypothesis, and it might apply to humans, too. In whales, if both the mother and her adult daughters are giving birth and raising calves simultaneously, the likelihood increases of the mother’s calf dying. That’s because the mother is trying to feed her new calf while helping to feed her adult children and their offspring.
Nature apparently sees this as wasteful, so the mother whale takes on the grandmother role, helping her daughters as well as her sons and sacrificing her fertility for the good of the pod.
This hypothesis doesn’t carry over to other mammals. Elephants, for example, continue producing offspring throughout their lives, and grandmother elephants are wonderful role models, providers and caregivers to others in their herd. Researchers believe mother elephants have more support from other females in the herd.
Bird feeder tips
Just a reminder to keep close watch on your bird feeders during these rainy days. Wet seed in the feeders can quickly mold and become dangerous to birds. If you know a storm is coming, bring in your feeders. If they get caught in the rain, empty them when the rain passes, dry them and replace the seed.
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Pet love
If you’re looking for a new furry friend, you might want to attend the “Unleash the Love” Adopt-a-Thon and Celebration which runs from 11 a.m. to 3 p.m. Feb. 17 at Animal Rescue Foundation, 2890 Mitchell Drive in Walnut Creek. ARF will host more than a dozen other animal rescue groups who are bringing adoptable dogs and cats, puppies and kittens.
The celebration also will feature food trucks, music, face painting, free ice cream and other giveaways. Therapy animals also will be on hand, and free microchipping will be offered to the first 100 pets.
Animal Life runs on Mondays. Reach Joan Morris at [email protected].
