Naturalist John Muir’s famous quote, “The mountains are calling and I must go …” could be the call of the Western tanager as the brightly plumed songbird makes its annual spring trek from the tropics of Mexico and Central America to the mountain forests of western North America.
“Western tanagers pass through Utah’s Cache Valley every spring but sometimes, as we’ve seen this year, they linger and build up in large numbers before heading to their mountain destinations,” says Utah State University ornithologist Kim Sullivan. “This is called ‘staging.’”
Much like human travelers crowd airports when inclement weather grounds flights, the migratory birds have been “stacking up” in Cache Valley and attracting notice with their colorful feathers. Males have bright yellow bodies and reddish orange heads, with black and white wings and tails. Cache Valley residents in online chats remark the birds “look tropical” and wonder if the birds are “escaped pets.”
“These birds are very sensitive to barometric pressure,” says Sullivan, associate professor in USU’s Department of Biology and the USU Ecology Center. “We’ve had some cold weather during the past few weeks and the tanagers have hunkered down here in Cache Valley, before venturing to breeding grounds in coniferous mountain forests.”
The overnight dusting of snow that stunned many human residents of northern Utah as they woke up on May 23, was no surprise to the Western tanagers.
“The birds feed on insects and need to keep their body temperature up,” Sullivan says. “It was too soon to forage in the mountains.”
Enjoy the birds while you can, she says, because as June brings warmer temperatures, the tanagers will head for higher elevations, beginning with the males, as they stake out territory for breeding and nesting.
“From their distinctive mating calls, we can hear that they’re full of testosterone and ready to breed,” Sullivan says. “We’ll still see the less brightly colored females, which are greenish yellow and brown, around the valley. They’ll join the males in the mountains, once their mates have settled into the forests.”
She says there will still be plenty of interesting bird-watching around the valley and recommends two free, online resources, created by the Cornell Lab of Ornithology with National Science Foundation funding, to aid everyone from beginners to experts in birding and citizen science.
“The Merlin Identification, All About Birds Guide takes you through easy, step-by-step questions to help you identify birds,” Sullivan says. “It’s a great resource for all ages.”
Another online tool, called eBird is an online database of bird observations that provides scientists and amateur bird enthusiasts with real-time data about bird distribution and abundance.
“You can upload information about your bird sightings, including images and audio files,” Sullivan says. “This helps other observers around the world.”
Both resources are a wonderful way to learn about birds, she says.
“As we’ll all be close to home this summer, these free tools provide ideal activities for individuals and families,” Sullivan says. “And they’re something fun and free we can pursue in our own backyards.”
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Department of Biology and USU Ecology Center