A Gila Monster out and about on a spring day a couple of years ago. On mild days, these animals start to move away from often communal dens to springtime staging areas. They may take daily patrols, searching for nesting mammals and quail eggs. It’s common for hikers to report them on social media frequently within a few days’ time, usually in late February or early March, which is a reliable signal that the process has begun each year.
After a relatively unproductive weekend in the early Spring at higher elevation, I made a quick stop by a large rocky outcrop on the way home on a whim. I have been driving past this particular rock for more than a decade, always in a hurry somewhere or dead tired, always thinking “one nof these days, I’ll check that out; it has to be a den“. Well that day was the day, and of course, it was a winter den. This large blacktailed rattlesnake was laid out over a boulder getting some sun, with others another in the crevices behind it. I’ll check it out again next year in more prime conditions.
An Arizona Black Rattlesnake comes out of its den for the day on a warm Spring day. This site is shared by three species of rattlesnakes, and at least a few species of other snakes. As spring egress progresses, each will use the area slightly differently, emerging, staging, and eventually distributing on their own schedules.
A pair of Gila Monsters getting some of their first sun in the early spring, a couple of years ago. They had only recently made a short walk from an overwintering den, where they had buried themselves in dirt at the base of a boulder, to this staging area. Here, at least five individuals spend time doing, basically, this, for about a month before heading out to do their mysterious Gila Monster things.
One of a few Arizona Black Rattlesnakes hanging out at an overwintering site, ready and waiting for the cold to come. This was photographed in the fall at high elevation, where rattlesnakes gather in sometimes large numbers to den together in deep retreats.
This species is what locals often mistakenly refer to as “Timber Rattlesnake”, which it is not. Timber Rattlesnakes are a real snake, however, but not closely related to this one, and not found in the Western US.
A pair of Arizona Black Rattlesnakes take the prime spot at the den, with a half dozen or more shuffling throughout the day behind them. For these snakes, it’s early den egress time, when they stage at and near the den for awhile before heading out for the season. This den is shared by two other species of rattlesnakes, though, all using the rocky area slightly differently. These are the last to emerge, with the Western Diamondback Rattlesnakes and Blacktailed Rattlesnakes having already dispersed for the year.
This was photographed in the late Spring several years ago in southeastern Arizona.
A young Great Basin Rattlesnake I found high on a precarious rocky outcrop in the spring. Throughout the week, the remaining rattlesnakes yet to leave the den emerged and made their way down the hill. This one was one of the last to leave but eventually disappeared after a series of warm days.
There are at least five Arizona Black Rattlesnakes in this photo. It’s a winter den site, where multiple generations live together through the cool part of the year.
It’s not a great photo, but this is how these snakes are often seen. It’s a Striped Whipsnake; one of several seen cruising around a multi-species rattlesnake den in the spring. Personally, I’ve been clued into a good number of rattlesnakes hidden deep within crevices because of these much more observable snakes, and their preference for similar hibernacula.
I found this Blacktailed Rattlesnake with a few others hanging out around a winter den early in 2024. Unlike other rattlesnake overwintering sites in the area, this one does not seem to be shared with the other rattlesnake species that can be found there – just lots of blacktails.
Dens like this have been difficult to pinpoint in environments that are mostly open rock, but over time the specifics have become more apparent and sights like this come easier these days. I’m looking forward to a return visit this spring.
