I’m not a biologist, but if you’re a Townsend’s vole and find yourself in this situation, you’re not having a good day.

Owls and hawks are important predators, as well as house cats, weasels, coyotes, foxes, skunks, snakes, and the great blue heron.
National Audubon Society Field Guide to North American Mammals description of the Townsend’s vole

Oh yes, and bitterns.

Pity the Townsend's vole, an important food source in the diet of a large variety of predators at Ridgefield

Although I failed in my quest to find a bittern in the frost on the last day of 2010, the first day of 2011 rewarded me with a bittern on the ice — a hunting bittern on the ice.

The day started out promising when I glimpsed a blacktail buck on the drive down through the canyon and onto the refuge at Ridgefield, but after putting on a show the day before the rest of the animals seemed to be sleeping in. While the early hours weren’t crowded, as the morning wore on the visitors picked up rapidly and the big lens attracted a small crowd whenever I stopped.

On the far side of the refuge, I like to drive slowly along Rest Lake to look for bitterns, so I pulled over to let an approaching car past so that I could move at my own pace. Even as I was pulling over I noticed this bittern down below in the frozen channel and settled in to watch. Within moments the bittern struck into the grass and brought out this terrified vole.

Bitterns often like to dunk their prey in the water and so it gingerly stepped down the rim of ice, struggling not to slip, and then dunked the vole into the water. Or tried to at least, but failed, since the water in this section was still frozen. It seemed mystified for a moment and stood motionless before eating its meal undunked.

After taking a few environmental portraits of the bittern on the ice, I moved ahead just slightly to another nice location and waited for the bittern to come past. But a Land Rover came up behind me and the couple got out of their car (a no-no on the auto tour during the winter) to set up their scope to view the distant ducks and swans.

Not surprisingly I didn’t see the bittern again.

When I got to the end of the auto tour, I was going to go around again but my heart sank when I saw a nearly solid line of cars between Horse and South Quigley Lakes. I learned my lesson from Christmas day, when I should have left when it got over-crowded but didn’t, and headed home.

Ellie got an extra walk and playtime in the park, and extra hedgehogging as well, so all-in-all a fantastic start to the year for everyone but the vole.

Neither bittern nor vole was happy with the outcome of this dunk attempt, but the vole got the worst of it

From what I’ve seen, bitterns are one of a small number of birds that could play in the NBA based on their propensity to dunk. I’ve seen them catch voles and salamanders and snakes and frogs and, if possible, all of them get quick dunks into the pond while the bittern applies constant pressure with its large beak. It’s much too fast to be an attempt to drown the creature, it really is just a quick splash in the water, but I’m not sure what purpose it serves. This Townsend’s vole is coming up from a dunking and as I recall, got at least one more before it finally stopped wiggling and the bittern swallowed it whole.

I have seen bitterns hold snakes under the water for an extended period of time, gripping them with their bare feet, and that may have been an attempt to drown the snake, get it so cold that it would move slowly, or just keep the bitey-bits away from sensitive areas until pressure killed it.

One of the things I love about the auto tour at Ridgefield is a chance to watch animals in their natural environment at close range without disrupting them, you get to see things you’d never see on the trails. I had a chance to watch this bittern over the course of a couple days around Christmas of 2009. The first day it made several strikes into the grasses at the edge of South Quigley Lake but came up empty each time. The next morning, however, I was startled when it came up with a Townsend’s vole. So startled that I barely managed a picture. I had no idea they would go after prey that large and figured that would be its last meal of the day.

So I was even more surprised when it struck a second time and caught another vole, as soon as I saw it strike I heard the vole shrieking and was better prepared for pictures. The bittern still wasn’t satisfied, it caught a large salamander a while later and only then decided to slip back under the cover of the marsh. The cattails grow so thickly here that with a few steps it was gone from sight.

I have mixed feelings watching herons hunt for voles, on the one hand I’m fascinated by the patience and then swiftness of their attack. But my soft heart feels for the little mammals when I see their struggle and hear their panicked shrieks in the last desperate moments of their lives. And even though the ordeal lasts but a few seconds, in pictures their stares and cries haunt me in perpetuity.

In consolation, from what I’ve read voles don’t usually live more than a year anyway, so perhaps the herons aren’t shortening their lives that much. At least it helps me sleep at night. ;)

Many people seem shocked by the idea that birds might have descended from a line of dinosaurs that didn’t die out with the rise of the little furry mammals. Spend some time watching herons take their revenge on those little furry mammals and the idea doesn’t seem so far-fetched.

This great blue heron had the most efficient hunting streak I’ve ever seen, I saw it strike the ground six times and catch something every time. Three times it caught a Townsend’s vole like the one it’s swallowing here, three times Pacific treefrogs. The little treefrogs hardly seemed worth the effort but I’ve seen herons catch them many times.