Bluebird Update 7/3/2023

Bluebird Update 7/3/2023

By Kyle and Vicki

What purpose does our nestbox trail serve?

Mountain bluebirds are a cavity nesting species which rely mainly on holes in trees, often created by woodpeckers, to raise their young. This species of bluebird is believed to be on the decline in the West due to factors such as habitat loss and competition for limited cavity nests from invasive species like house sparrows and European starlings.

A fledgling bluebird from box 44 is fed by an adult on Monday at the Fish Hatchery. Photo Vicki Morgan.

Mountain bluebirds are among the first nesting songbirds to return to the Jackson Hole area each spring. There is likely some evolutionary strategy at play here; by returning when the ground is largely still snow covered bluebirds risk exposure to lack of food and cold temperatures, but gain an advantage over rival species when it comes to snagging limited nesting sites.

Our trail of volunteer-built nestboxes on the National Elk Refuge’s western boundary not only provides bluebirds with much needed nesting locations, but allows scientists a chance to gain a more complete understanding of the overall health of this sub-population.

How are the bluebirds faring this spring?

Overall, we’re confident 2023 has been a good year for bluebirds. While we won’t have a full dataset until the end of the summer, reports from our banding team and volunteers indicate bluebirds both returned to the trail and nested in relatively high numbers this spring.

While spring conditions imperiled some nestlings early in the season, wet conditions are likely to foster increased numbers of insects later in the summer which may benefit second rounds of nests. Photo: Vicki Morgan.

At one point, 16 active nests were recorded, more than were active over the entirety of last season. According to Lead Bird Bander Vicki Morgan, who surveys boxes and organizes volunteer data weekly, there are currently two to three boxes with nestlings about to fledge, and between four and six boxes where bluebirds are on their second attempts at nest building.

Several fledglings from box 44 were even “hanging out” at the Fish Hatchery parking lot, where they were being fed by their parents as of Monday morning (don’t all go to photograph them at once!).

The success of nestboxes this year can at least partially be attributed to last year’s batch of fledglings. At least four nest boxes contain female bluebirds which were banded last year as chicks. These birds migrated away last winter and have since completed successful return journeys back to the National Elk Refuge to build their own nests, usually within hundreds of meters from where they themselves hatched. The fancy phrase for this is “site fidelity.”

What are the challenges facing this year’s nesters?

Still, bluebirds on the nest box trail have faced challenges in 2023. While nest building jumped off to a quick start, insects were slow to emerge due to late-spring weather patterns and a handful of nests failed with a lack of available food for nestlings. While nest failure is a natural and normal process, it doesn’t mean it can’t be frustrating to witness young birds not make it, especially when you’re rooting for team bluebird! Several of our boxes have also experienced predation in recent weeks. Our best guess is that weasels are the culprit – snakes can also fit through nest box holes but generally devour young birds whole. Weasels on the other hand are prone to leaving  behind “nestling bits” as evidence of their transgressions.

A 2023 fledgling with this year’s diagnostic color-band combination. Photo: Vicki Morgan

Are the nestboxes helpful for the birds?

We believe they are. Although not all nestling birds survive (you’re welcome weasels – for the buffet), the fact that many bluebirds do successfully fledge indicates the Mountain Bluebird Nestbox Project is likely having a net positive effect. Two years ago, a bird banded on our trail was recaptured and released in Texas during winter migration. And each year more and more “resights” of birds banded in previous years pour in. It’s going to take more than one productive year to help ensure the longevity of this species in our region, but that doesn’t mean we can’t get excited about this season’s results!

Surveying Snakes on The Refuge

Surveying Snakes on The Refuge

GUEST BLOG: The Jackson Hole Wildlife Foundation asked our friends and fellow Nature Mappers, Betty and Chuck Mulcahy to share a bit with us about their current volunteer work at the National Elk Refuge. Betty and Chuck do a lot to educate the public about the wonders of snakes and demystify their wicked reputation. Don’t be afraid, read on and learn about our serpent friends:

“Count the snakes and keep your distance!” a friend warned in an email after we told her our new assignment for biological work on the National Elk Refuge was to survey reptiles, mainly counting the snakes.

Unknown to her, the snakes in Jackson Hole are comprised of three non-venomous species.  Because one species, the rubber boa, is nocturnal, we don’t expect to encounter it on our rounds, although our biologist mentioned he had seen one once during the day.

The other two species are the wandering gartersnake and the valley gartersnake.  The wandering gartersnake is the more numerous and is unlikely to bite if picked up.  Instead, this species prefers to defend itself by exuding a musk in your hand, much like pooping.  As we tell school children when we present a reptile program in their classrooms, this defense is very effective due to the pungent odor!  Their response is always the same:  “Eeeeeew!”

However, locating snakes on 25,000 acres can be tricky – perhaps likened to searching for the proverbial needle in a haystack.  Our long-time mentor in snake locating is a Denver Zoo reptile keeper, as well as rattlesnake researcher, who can find a snake with the ease of a professional.

In the past, we have spotted snakes on top of Miller Butte, thermoregulating across roads, swimming in creeks, and hiding in sidewalk cracks and under steps.  Now, scouring the Refuge, we flip rocks, turn logs, lift tarps, and trudge through thick vegetation in our search.

Because snakes have yet to be surveyed on the Refuge, no precedent is set for their documentation.  Consequently, we outline our search area on a map and record date and findings in a comment section.  Finding nothing is as important to record as our successes, according to our biologist, as is recording any dead serpents.

While the wandering gartersnake can often be found at a distance from water, the valley gartersnake is found more often near water and is believed to have declined in population over the years.

We hope to encounter each of these species!

̶ Betty and Chuck Mulcahy



To keep up-to-date on Betty and Chuck’s survey and other adventures you can follow along via their blog Have Snakes Will Travel: The Unconventional Lives of Volunteer Naturalists.

For more detailed information including photographs on the three snake species found in Teton County, WY visit the following links:

  • Northern Rubber BoaCharina bottae – looks like a fake rubber snake, with its lack of distinctive head or tail or any markings. In Wyoming, it is found only in the mountainous northwestern region.
  • Wandering GartersnakeThamnophis elegans vagrans – is by far the most common gartersnake in Teton County and ranges across the state. The body background color varies from brown to olive, and the stripes and markings can vary in intensity, but it will not have red.
  • The Valley GartersnakeThamnophis elegans fitchi – has a very limited range in Wyoming: the very western edge of Teton and Lincoln Counties. It is distinctive from the Wandering Gartersnake by its red accents.



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