NATURE NOTES:
Keeping an Eye on the Winter Hummingbirds of the Trans-Pecos

By Andrew Stuart

West Texas boasts among the greatest diversity of hummingbirds of any region in the country. Each year in late summer, birders convene in Fort Davis for the Davis Mountains Hummingbird Celebration, as thousands of hummingbirds pass through on great migrations.

But in West Texas, hummingbirds aren’t just a summer phenomenon. Some of these charismatic, high-energy creatures winter here – and their numbers are growing.

For those who hang hummingbird feeders – and for other nature lovers – it’s a fact to be mindful of.

Hummingbirds are remarkable creatures. Peerless in their maneuverability, they’re also peerless in their metabolism – their hearts beat a thousand times a minute. Many migrate thousands of miles.

And they’re true New World creatures, found only in the Americas.

Hummingbirds eat small insects – baby aphids and spiders, gnats and midges. But plant nectar gives them energy for the hunt, and they likely evolved in the plant-rich tropics.

“And then some hummingbirds, as they ranged out over time, found niches that they could occupy in North America and all the way to Alaska.”

That’s Kelly Bryan, ornithologist and former Davis Mountains State Park superintendent. His study of birds has only intensified since his retirement from the parks, and he recently completed a 10-year hummingbird study.

The deck of his Davis Mountains home is lined with hummingbird feeders.

“Here in West Texas, we’ve got the highest diversity of any other location in Texas,” Bryan said, “and Texas as a state now has the highest hummingbird count for the U.S., because, at this location, on Oct. 14, 2016, an amethyst-throated hummingbird showed up right there on that feeder.”

That sighting brought the Texas count to 19 – of which 18 occur in the Trans-Pecos.

There are hummers that regularly nest in the region. But for many species, the Davis, Guadalupe and Chisos mountains are critical stopovers between northern breeding grounds and tropical winters.

For some hummers, however, West Texas is the winter home.

The first records were in the late 60s. But occurrences are increasing.

The use of hummingbird feeders may be a factor. But Bryan said the region has always supported winter populations. He spotted two species in remote Big Bend Ranch State Park 20 years ago.

“I found hummingbirds along several tributaries of Fresno Canyon,” Bryan said, “and those birds had no feeders whatsoever. They were feeding on insects and flowers that were persisting on the canyon walls. So that just shows you that the hummingbirds have been here all along.”

Insulated with feathers, with body temperatures of 106 degrees, hummers can handle cold.  And they’re uniquely adapted for freezing nights.

“Hummingbirds are built differently than other birds,” Bryan said. “The way they deal with cold weather, they go into a hybernetic state called torpor. That’s basically a metabolic-shutdown state, where they go into what looks like a coma, for the night. They can go from a normal heartbeat rhythm of 600 to 700 beats per minute down to 50, and respirations will be cut by 75 percent.”

In torpor, they conserve their energy. The adaptation allows hummingbirds like the rufous to nest in the high Rockies. A rufous was spotted in Lubbock County – in light snow and 18-degree temperatures.

Climate change may be contributing to increased winter populations. And though feeders may not increase wintering numbers, they definitely increase sightings. There are winter sightings at feeders in the Trans-Pecos and Llano Estacado.

Feeders won’t deter birds from migrating. But West Texans with feeders can do wintering hummers a favor.

The birds seek a sweet jolt at daybreak. Homeowners should ensure their feeders don’t freeze overnight.

Sugar water freezes at 27 degrees – warm solution can be added on cold nights. Bryan has his own technique.

“What I used to do is to take one of these cheap reflector lights,” Bryan said, “one of these things that has the clip-on handle – and just put a 40-watt bulb in it, and put your feeder in a position to where you can clip your light on to something, and have that light just radiate up to the feeder base. It will be sufficient to keep a feeder unfrozen all night long.”

Feeder solution should be one part sugar to four parts water, with no additives or food coloring. With a little care, a hummingbird feeder can bring the birds’ distinctive vitality into your West Texas winter.