Weather Watch

Anna’s hummingbirds adapt during rainy season

An Anna’s hummingbird’s beautiful hues are generated by microscopic platelet structures on its feathers, which give the appearance of changing color from different angles.
An Anna’s hummingbird’s beautiful hues are generated by microscopic platelet structures on its feathers, which give the appearance of changing color from different angles.

It’s been said that creatures on average have somewhere around 1 billion heartbeats over a lifespan.

The theory is that the bigger the animal, the slower its heartbeat.

Consequently, the longer it will live.

A blue whale has an average heart rate of less than 20 beats per minute as it swims through the ocean with slow grandeur with an average lifespan of 80 years. A house cat has a heart rate of around 150 beats per minute with a typical life span of 15 years. Of course, individual cats or dogs may live longer, but I’m referencing groups, not individuals.

At the other end of the spectrum are hummingbirds.

These high-energy critters have a heart rate that can reach more than 1,000 beats per minute while in flight. Excluding insects, they have the highest metabolism rate of any animal on Earth; and no wonder, with the hurried beat of their wings they can hover or dart through a garden as fast as 45 mph. Unfortunately, they have a relatively short lifespan, no longer than nine years.

Along the Central Coast, Anna’s hummingbird (Calypte anna) can often be seen in residential areas. Surprisingly, they don’t migrate very far. Some may travel to higher elevations in the summer, then back down to the coastal valleys in the winter. As many birdwatchers will tell you, many of them become permanent residents.

However, because of the planting of flowering shrubs and trees that provide nectar, increasing numbers of hummingbird feeders and a warming climate, these flying bright pink and emerald green ornaments have expanded their range from Baja and Southern California to as far north as British Columbia. In fact, these birds have been spotted in southern Alaska. The beautiful hues are generated by microscopic platelet structures on the hummingbird’s feathers, which give the appearance of changing color from different angles, much like oil on water.

Anna’s hummingbirds primarily eat nectar from flowers or drink sugar-water from feeders. They also eat sap from trees and catch small insects and spiders.

A few years ago, one of these hummingbirds built a nest and raised two chicks near the Ocean Lab at Diablo Canyon nuclear power plant. The nest was cleverly camouflaged with leaves, mosses and lichens. The eggs were white and about the size of a navy bean. After a few weeks, they hatched. The next time I saw them, they were covered in down and stayed in the nest for a few more weeks before they fledged. The mother and the two chicks flew around the area for days afterward.

During cold weather, these birds have an amazing way to protect themselves and save energy. They lower their internal thermostat, becoming hypothermic, by going into a state of torpor.

Marcia Beckley-Kane of Atascadero discovered that these hummingbirds love the rain and that her feeders are the busiest in heavy downpours. And no wonder, the rainy season usually signals the start of their courtship rituals. The bright-colored males climb as high as 130 feet in the sky and then nose dive while belting out chirps for their prospective mates.

Marcia is an amazing photographer and has a Facebook page called “Central Coast Hummingbirds.” She usually posts a new hummingbird photo once a day with some interesting hummingbird information.

“We are very lucky that the Anna’s hummingbird lives on the Central Coast year-round,” she said. “Please remember, if you have a hummingbird feeder it’s important to maintain them with fresh sugar water throughout the winter months so they can survive, breed and give them the energy they need to raise their babies.”

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Did you know that PG&E delivers to its customers some of the nation’s cleanest electricity? More than 55 percent of the power comes from sources that emit no greenhouse gases, including Diablo Canyon nuclear power plant. To learn more, please visit www.pge.com.

John Lindsey’s column is special to The Tribune. He is PG&E’s Diablo Canyon Power Plant marine meteorologist and media relations representative. Email him at pgeweather@pge.com or follow him on Twitter @PGE_John.

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