For many, if birds and climate change are mentioned in the same sentence, it conjures an image of the canary in the coal mine. These delicate, beautiful creatures are sensitive to ecosystem changes and respond to differences more quickly than we large, heavy bipeds do. These days, mining in the Roaring Fork Valley is minimal and oxygen saturation underground can be detected by handheld machines instead of songbirds. Yet birds still serve as warning signals for humans, at least to those who watch.
Some of the birds sending the clearest signal in the Roaring Fork Valley are also some of the most popular: hummingbirds and ptarmigans. Hummingbirds are a favorite for many people; some, who may do no other type of birdwatching, meticulously make note when the first hummingbird of the year arrives in their yard, and carefully maintain feeders for the tiny creatures to have consistent access to calories. Ptarmigans particularly captivate alpine enthusiasts as the smallest bird in the grouse family inhabiting treeline or higher elevations.
Increasing temperatures in the Colorado Rockies are affecting whether we’ll continue to encounter these birds. Our regional mountain valleys used to host more broad-tailed hummingbirds in warmer months than we see today. Experts and avid watchers have seen fewer and fewer of them, and not just anecdotally. This past spring, CBS Colorado covered reports from the Bird Conservancy of the Rockies and the Audubon Society regarding the change.
Broad-tailed hummingbirds are adapted to cooler climates than many other types of hummingbirds. Accordingly, they are inclined toward higher elevations when food sources are available. The reports indicate that broad-taileds have experienced a population decrease of almost 50% since 1970. The population has plummeted by 30% since 2014.
The decreasing numbers of broad-tailed hummingbirds doesn’t mean we’ll say goodbye to their cousins. It may mean saying hello. Black-chinned hummingbirds, typically adapted to desert climates, have been steadily moving into our mountain ecosystems as temperatures increase. Pollinators on the whole are in danger, though. Many pollinating insect species populations are also decreasing in Colorado, which has broad implications for ecosystems’ other plants and animals.
This includes ptarmigans. The decrease in food access is just one of many stressors for these seasonal color-changing birds. Rebecca Weiss is a birding guide and naturalist who works with the Aspen Center for Environmental Studies (ACES) and the Rocky Mountain Biological Laboratory in Gothic, Colorado.
“Ptarmigans are decreasing and their observed range is decreasing,” said Weiss. Insect abundance related to moisture levels is decreasing, she added, and that affects bird species. Increasing aridity and temperatures stress and reduce pollinator populations at altitude, affecting the plants available for ptarmigans to eat. Competition is a problem, too. “As other birds’ ranges expand and temperatures increase, ptarmigans lose available space,” Weiss stated.
Ptarmigans are the only North American bird species that dwell completely in the alpine zone. Like their neighbors, the adorable rodents we know as pika, rising temperatures represent a significant threat to their habitat. And mountains aren’t rising to create additional real estate for them.
Weiss wanted to reassure people that change isn’t always bad. “Locally, we are observing range expansions of birds previously only seen downvalley,” she shared. Species with expanding local ranges include great blue herons, osprey, Bullock’s orioles, Say’s phoebes, pygmy nuthatches and Lewis’s woodpeckers in addition to the aforementioned black-chinned hummingbirds. These expansions “show birds are capable of being flexible,” Weiss pointed out. “We just don’t know how far their adaptations [will] go.”
For readers interested in the science behind it, or some casual birdwatching, there are a number of opportunities in the Valley. Weiss enjoys teaching newcomers the practice through her programming at ACES. “We welcome people of all experience levels,” she said. “We cater to novices and what I call the bird-curious.”
The Roaring Fork Audubon Society also offers a variety of events throughout the Valley. Bird sightings on its field trips are carefully tallied so that numbers can be submitted to the Cornell Lab of Ornithology and National Audubon Society to help measure larger trends. If you want to take action to support stressed species that have historically called the Valley home, the Audubon Society can provide guidance on how to do so. Visit www.roaringforkaudubon.org for more information.
To help make a difference, folks can also look into rewilding their gardens by removing monocultural lawns and instead growing wildflower species and local grasses. For tips on that, visit www.fws.gov/story/how-build-pollinator-garden