Have you been to see the carnivorous plant Bog Garden in the Monkey Trails and Forest Tales habitat at the San Diego Zoo? If not, definitely make it a priority next time you're here. These fascinating insect-devouring plants are as beautiful as they are remarkable. The Bog has been one of our most challenging horticultural features and also one of the most satisfying. Only about 10 feet across by 6 feet wide (3 by 1.8 meters), the Bog gets more than its fair share of attention from horticultural staff as well as the public. Venus fly traps Dionaea muscipula (pictured), sundews Drosera species, and the spectacular North American pitcher plants Sarracenia species grace this small garden just left of the golden-bellied mangabeys on lower Monkey Trails.

The most challenging species is also the most recognized. Venus flytraps are endemic to North Carolina and ranging a bit into South Carolina. These predators of the Plant Kingdom endlessly fascinate both kids and adults. Many a child has brought home a Venus flytrap at some time and killed it. Many times what does the plant in is the wrong kind of water. Carnivorous plants can't take tap water. We run deionized, or DI, water through the Bog. Our challenges don't come from the water, but instead from people and other critters.

The first flytraps went into the Bog just before opening Monkey Trails in June, 2005. Flytraps do most of their growing in the warm season. One of the earliest issues we had was humans wanting to see the traps up close. It is, after all, an amazing thing to touch a plant and see it react so quickly, its jaws snapping shut. Unfortunately, though, this wastes a lot of the plant's energy without any reward. Actually, Charles Darwin theorized that the reason the jaws don't close all the way is to allow smaller prey to escape, since the payoff isn't worth the energy it takes to digest them. I used to find a lot of small pieces of grass or sticks that guests had thrown into the Bog in order to try to get the traps to close. I put up signs asking to please not throw things in, and for the most part, this seems to be working. Mostly it's just that folks don't know it will hurt the plants.

So, first humans, and then the ducks started coming! I walk by the Bog every morning around 6 a.m., and for months last fall and winter I found wild ducks happily trouncing around the bog, splashing in the watercourse, walking all over the plants, and, worst of all, leaving their " fertilizer" all over the Bog. I spent many a late morning with rubber gloves removing that duck stuff from the surface. Carnivorous plants grow in the poorest of soils, and they don't like fertilizer. While the duck excrement would probably be great for most plants, it was destroying many of the Dionaea and Drosera in the Bog.

For a solution, we started adding some mangled long sticks around the edges of the garden, hoping it would discourage the ducks. It looked like they were walking, as opposed to flying in. So we thought maybe we could artfully blockade the area. It did help. We also decided to completely remove the " watercourse," a small stream running through the center of the Bog providing all of the water circulating through. We ended up using a drip tube run across the area where the watercourse had been, with microjet risers to add water to the Bog, hopefully without too much pooling. So far, so good! The ducks have all gone back to Flamingo Lagoon, it seems. I haven't seen one in the Bog in months. Winter is coming, though. The flytraps are beginning to go into their dormancy period. If we can keep the ducks out, perhaps they will make it through the winter. Time will tell.

Mychael McNeeley is a senior gardener in Monkey Trails at the San Diego Zoo.

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