SnakeOnce upon a time, you couldn’t see tarantulas or snakes or monkeys at Shedd Aquarium. Then, in 2000, Amazon Rising opened a new era of exhibits at Shedd. In the curving gallery’s big floor-to-ceiling habitats you can see animals that live in the river, on the floodplain forest floor and even up in the canopy—together—in a portrayal of the most diverse and complex freshwater ecosystem in the world.

In another departure from traditional exhibits, Amazon Rising not only transports you to the steamy floodplain forest, but it also walks you through a complete year on the same stretch of river. Moving through the seasons—and corresponding levels of the Amazon—you can see exposed riverbanks at low-water season and a stilt-leg house up to its porch in piranhas during the annual floods.

The rhythmic rising and receding of floodwaters bring dramatic changes to the floodplain forest.

Ten years have also brought changes to Amazon Rising, perhaps none more breathtaking than the growth of the green anaconda.

When the female constrictor moved into the Floating Meadow habitat, shortly before the exhibit opened, she was 5 feet long and no bigger around than a broomstick. In fact, she looked skinny. "That’s normal for a 1-year-old anaconda," says Jim Watson, a senior aquarist who has worked in Amazon Rising since the beginning and watched the snake grow.

Today Jim estimates that she’s 14 feet long, between 100 and 150 pounds and 12 inches at the thickest section of her body. That makes her Shedd’s longest animal, ahead of the green sawfish in Wild Reef and beluga whale Naluark, both about 13 feet long.

And she’s still growing.

The green anaconda (Eunectes murinus) is the largest snake in South America and one of the world’s top three big snakes (the other two are Asian and African pythons). Most herpetologists, or reptile experts, consider 26 feet to be the species’ maximum length, but anacondas longer than 15 feet are rare in the wild these days.

If it is not the longest snake species, the green anaconda definitely is the heaviest. A 26-footer can weigh 400 pounds or more. Shedd’s exhibit can handle that. But the snake has outgrown regular hands-on interactions with staff members.

Jim says, "She was raised by a breeder, and he got her accustomed to frequent handling for us. We handled her regularly, up until she got to 9 feet long and it took five of us to do a physical. She is a big, powerful animal, and she doesn’t go along with being touched as much as she used to."

He points out that positive reinforcement, the training technique used with so many of Shedd’s animals, using treats and pats to reward desired behaviors, doesn’t work as well with an animal that can go weeks between meals and doesn’t enjoy being touched.

Instead, Jim continues, "We have a reserve space behind the exhibit, and she’s used to going there to sleep. We can gate her there, so it’s easy to get a good look at her and keep track of her condition." All of the aquarists who work with the anaconda have been trained in handling large constrictors and, Jim says, "We would handle her if it was necessary, if we felt something was not right with her."

Another gauge of the snake’s health is her appetite. Anyone can see that it’s robust—during public feedings every other Wednesday at 11:30 a.m. She’s fed either a small-to-medium-sized rabbit or a couple of extra-large rats (all commercially raised for food).

The semiaquatic snake loosely loops herself around submerged logs in her 3,300-gallon pool the same way her counterparts in the wild would lie in ambush for prey coming to a stream bank to drink, so some part of her is usually visible underwater. The habitat’s side window sometimes offers a good angle to see her face. Watch for just her eyes and nostrils above the water’s surface.

Karen Furnweger, web editor