August 27-September 2, 2023

There were several days of rain early in the week that moistened the soil, cleared our smoky skies, and made the air smell fresh and crisp for the first time in a long while.

Week in Review

What a fun week this has been. We went from dousing rain and cold temperatures at the beginning of the week, back into glorious hot days just in time for the holiday weekend at the end of the week!

Tom Forker shared some wonderful photos from an outing to Harts Pass during the rain—it was a lovely reminder that it's always worth getting out when the weather seems the worst. Plus, it was exciting to see from his photos that huckleberry leaves have started turning red in the mountains!

There have been many other small reminders of the changing seasons this week as well. For example, at the end of the week a large flock of over 100 phalaropes showed up on Big Twin Lake. Our lakes and marshy areas attract a variety of migrating shorebirds, and this is the time of year when they stop briefly at these locations as they migrate south. (Later that same day, the phalaropes were joined by five gulls and a large flock of migrating northern shovelers!)

You might still be noticing juvenile birds at this time of year, such as the juvenile great blue heron that has been spotted at ponds on the Twisp-Carlton Road. While most juvenile birds can be recognized by their crisp, bright feathers, a larger bird like a heron can have a dingy, unkept look because it takes these birds longer to grow all their feathers.

This was also a good week to look for insects in these cooler temperatures. I posted a picture of a brilliant green swallowtail caterpillar two weeks ago, and this week I was surprised to find one that was brown! (I researched this and learned it means that the caterpillar is getting ready to spin a cocoon and pupate for the winter.)

And I don't know if this is tied to the seasons or not, but I also noticed an ant nest with winged adults emerging to fly off and start new colonies. I'm guessing that new queens need enough time to mate, find a hole in the ground, and start a new colony before winter sets in.

September is going to be a fantastic month for observing the changing seasons, as both plants and animals undergo a mad rush of preparation for the coming winter! Be on the lookout for changing leaves, migrating birds, and mammals eagerly eating as much food as they can find!

Observation of the Week: Denning Rattlesnakes

Our most feared and misunderstood animal is probably the western rattlesnake. In the past, and in many areas presently, these misconceptions have had a huge impact on rattlesnake populations, but we are fortunate in the Methow Valley that so many people respect and look out for rattlesnakes.

I say that we are fortunate because rattlesnakes can be the most significant predators keeping populations of small mammals—such as mice, ground squirrels, packrats, and even marmots—in check.

Rattlesnakes are relatively common in the Methow Valley, but they are also locally distributed because their life centers around their denning sites. Dens are usually located on rocky, south-facing slopes and they are places where dozens of snakes gather to spend the winter together under rock piles or in rock crevices where they can avoid freezing temperatures.

Rattlesnakes emerge from their dens on warm days in the spring. And after resting for several days or weeks around the den, males will wander a mile or so in search of feeding areas where they spend the summer.

Pregnant females, however, remain around the den, scarcely moving and rarely, if ever, eating as they bask in the sun and let their embryos grow. In fact, after females give birth to live young in September, they promptly re-enter the den for the next winter and may end up going 19 months without eating.

Rattlesnakes generally remain motionless, or move slowly, to conserve energy. Even in the best of times they might easily go weeks or months between meals because it's rare that a food animal walks within striking distance of a waiting rattlesnake, and even when this happens and a rattlesnake strikes, they miss their target half the time.

On top of that, a rattlesnake cannot obtain food and eat unless it has venom, but venom is a complex protein that takes a lot of time and energy to produce, which means a snake is very reluctant to waste venom, or to waste venom on a large animal (like a human) that it is not going to eat.

It's easy to think of rattlesnakes as fearsome, aggressive creatures that need to be fought back, but nothing could be further from the truth. They are actually extremely vulnerable and have little physical strength because they use venom to subdue their food. Their only defense is coiling up and rattling their tail, and only if threatened or scared will they strike as a last recourse.

Sadly, because of their lifestyle, rattlesnakes grow very slowly and females don't start breeding until they are four to seven years old, and after that they breed once every two to three years.

If only a handful of the older females are capable of producing young it means that killing a few snakes can have a devastating impact on their populations, but there's usually no reason to kill a rattlesnake anyway. They are largely sedentary, so if you find one in your yard it's far better to have someone safely move it anywhere from 100 yards to a quarter mile away.

They shouldn't be moved farther than that because they are utterly dependent on a winter den site that each snake uses for its entire lifetime, and if they get moved too far away they have no chance of finding another den site.

If you have questions, concerns, or would like assistance with a rattlesnake you can always contact John Rohrer, a retired biologist who has spent years moving rattlesnakes and helping people understand their lives. John can be reached at (509) 429-8970.