wildlife

I know it’s irrational but these things continue to terrify me. From Sherman Ave.

Photo via Wikipedia by Quadell

Urban Wilds is written by Lela S. Lela lives in Petworth. You can read Lela’s first post on Wood Frogs here.

Eastern Skunk Cabbage

Skunk cabbage is called that for a reason, and you can sniff out these wetland plants with your eyes closed. But in early spring, they’re most visible as some of the very first plants to begin to flower, sometimes when there’s still snow on the ground. In a reversal of my last post, they do this by actually generating their own heat. In the process of warming themselves up, the plants burn through a huge amount of oxygen – as much by weight as a hummingbird would use. This thermal mechanism is two kinds of good for the skunk cabbage. The heat protects their developing tissues from the cold, letting them actually melt through layers of snow or ice and get a jump on other plants. It also warms and helps to disperse the molecules that make up the plants’ particular smell, attracting early-hatching insects. That fragrance contains chemical compounds similar to those in rotting flesh, wonderfully called putrecine and cadaverine. I think the smell is kind of delicious, in a woodsy way.

Look for young skunk cabbages in low-lying, wet areas in early March – Rock Creek is always a good bet. Their purple and green spathes (bizarre, twisted pods containing the flowers) should be visible now, and the plants may be leafing out. Later in the spring, the big, vigorous leaves can completely dominate an area, crowding out the competition in a thick blanket of green.

Now that we know there really are owls in DC do you think these plastic owls really work? If so, what do they scare away – mice? rats? pigeons? squirrels?

Photo via Wikipedia by W-van

Urban Wilds is written by Lela S. Lela lives in Petworth. You can read Lela’s first post on Great Horned Owls here.

For wood frogs, our recent warmer-than-usual temperatures must be existentially boring. These pretty little brown frogs are widespread along much of the East Coast and Midwest, across a swath of Canada into Alaska. They’re the only amphibians that live north of the Arctic Circle. In winter, wood frogs hibernate near the forest floor, digging under leaves or shallow layers of soil, where they are still exposed to freezing air temperatures. When the mercury drops, they perform a trick we still don’t entirely understand: freezing almost solid. The frogs’ bodies produce cryoprotectant substances including glucose, which protects their cells from being damaged by ice crystals. As they grow colder, the water in their body cavities turns to ice; their hearts stops beating; and even the lenses of their eyes freeze and turn white. Eventually, more than half of the water in the frog’s body can be solid ice. Wood frogs can freeze and thaw multiple times in a season, and we know they can survive at least four weeks of being continuously frozen.

In the DC area, wood frogs mate in March and lay their eggs in vernal ponds, temporary pools that appear during the spring thaw. At only about two inches long, they’re hard to spot – try listening instead. Rainy nights are the best time to hear them chorusing en masse, with distinctive calls that sound, weirdly, a little like the quacking of ducks.

Photo by PoPville flickr user mosley.brian

Urban Wilds is written by Lela S. Lela lives in Petworth.

Great Horned Owls

Why now:

The biggest owls in DC are nesting right now, making it the perfect time to hear them. Great Horned Owls are at their noisiest in late winter, hooting back and forth to each other as they try to find a mate. Once they pair off, the owls will build nests inside hollow trees, or take over abandoned hawk nests. Over the next few months, they’ll raise two or three owlets, feeding them with selections from the city’s rat population and other choice edibles.

The Great Horned call is a classic “who who whooo, who, who,” though they can also bark and (unnervingly) shriek. Despite their size – with wingspans of up to four feet – you’re more likely to hear an owl than to see one. If you’re lucky, you could spot one at twilight, flying over fields close to the edge of the woods.

Where and how to find them:

Great Horned Owls are residents of Rock Creek and the National Arboretum, and have been seen in other parts of town. Listen for them calling between dusk and midnight, or just before dawn. During the daytime, sometimes crows will ‘mob’ an owl to drive it off. If you hear a group of crows making noise, chances are good that they’re heckling an owl, and you might catch a glimpse of it flying away.

(You’ll probably never come face to face with an owl. Just in case, keep in mind that owls and their nests are protected under federal law. Enjoy from a distance.)