Essay: Tracking a hummingbird's arrival, for fun and science.

It’s that lovely time of year when folks—myself included—don floppy hats, binoculars and notepads to monitor our migrating feathered friends.

We're a big bunch: there are an estimated 47 million birders in the U.S. And we play an increasingly important role: scientists need more than our interest and camera phone pictures for one important pollinator, the hummingbird. They need our observations. As climate change threatens hummingbird habitat ranges they’re reaching out to birders to help track their habits and health.

Climate change creates imbalances in temperature and migratory bird timing, and scientists say hummingbirds, which are important wildflower pollinators in North America and food pollinators in tropical regions, are particularly vulnerable. A warming climate can alter when flowers bloom. This earlier blooming can create a mismatch between hummingbird arrival and flowers, which they suck nectar from throughout the day to stay alive.

A 2014 report from National Audubon Society scientists is grim: Hummingbirds could lose vast amounts of their current ranges over the next 60 years if climate change continues on its current path.

I'm still new to the past-time, but I love when a Ruby-throated hummingbirds make their way to Michigan around early May. It’s the only regular hummingbird visitor to the Mitten-state and watching them dip their straw-like beak into a flower or feeder while hovering like an overgrown insect is always special.

“Hummingbirds co-evolved with feeding sources, these nectar sources should be blooming to coincide with their arrival,” said Kathy Dale, Audubon’s director of citizen science. The flutterers are crucial pollinators, mostly wildflowers when they’re in North America. However, there are food system concerns as hummingbirds help pollinate some tropical crops such as bananas, papaya and nutmeg, according to an Audubon report.

Some dire findings from the Audubon report: The Allen’s hummingbird, a mostly rust colored bird that breeds in southern Oregon and coastal California, is projected to lose 90 percent of its current breeding range by 2080. The tiny Calliope hummingbird and the Ruby-throated hummingbird may find just 22 percent and 27 percent, respectively, of their current summer range stable come 2080.

University of Maryland researchers reported in 2012 that in the northern slice of the Broad-tailed hummingbird's breeding area in Colorado, glacier lilies were blooming about 17 days earlier than they did in the 1970s. The study found that the time between the first-arriving Broad-tail and the first flower had shrunk by almost two weeks.

Such timing mismatches could reduce nesting success, said Nickolas Waser, senior author of the 2012 study and an adjunct professor at the University of Arizona. “This is especially concerning in higher elevations,” he added.

Blooming differences high in the Rocky Mountain Biological Laboratory in Colorado, for instance, were not as pronounced in Arizona.

Droughts in places such as Colorado can worsen the problem: Waser reported last month that drought reduced both pollen and nectar production in scarlet trumpet flowers. 

David Inouye, professor emeritus at the University of Maryland, has been studying pollinators at the Rocky Mountain Biological Laboratory for more than 40 years. “I was just out hiking the other day and saw [a species of Indian paintbrush] flowers but didn’t see any hummingbirds,” Inouye said, adding he was hiking at about 5,500 feet altitude in Colorado.

Hummingbirds' ability to adapt remains to be seen. This is where us birders come in: Dale and colleagues are hoping some citizen science can help—through (what else?) an app called “Hummingbirds at Home.” As you monitor birds in your yard, log in and note when they’re visiting and what they're eating.

“We’re trying to get citizen scientists to tell us when birds are visiting nectar sources, when they’re feeding,” Dale said. “Some people do it everyday.”

That’s the nice thing about us birders—we’re an ardent bunch. Dale points to Audubon’s use of citizen science going back 100 years. “It’s always been people out in communities first raising the issue of challenges for birds and their habitat,” she said. “When I go talk with people they always want to talk about the first big sighting they had this spring.”

(Ahem, yellow-rumped warblers near Connor Bayou here western Michigan, 4/16/16)

This is Audubon's fourth year offering the app; about 25,000 people are signed up. Dale said they are starting to sort through the data and will start publishing some findings over the next year or so.

It shouldn’t be too hard a sell. Watching a hummingbird’s vibrating hover in a lush garden is one of nature’s great delights.