International Rock-Flipping Day

When was the last time you flipped over a rock (or a log) to see what was underneath? You can find all kinds of cool creepy-crawly things under there, if you're lucky. Our coolest finds over the years have included salamanders and enormous beetles. You never know until you look.

In this spirit, Dave Bonta and Bev Wigney started International Rock Flipping Day in 2007. This year, it is being observed on Sunday, September 20. To inspire you to get out there and flip some rocks this weekend, we've started our rock-flipping a few days early. All of these critters (and one cool patch of mycelium) were found as we flipped the many rocks in our backyard in Silver Spring, Maryland, this week:

Now get out there and join in!

• Find a rock and flip it over.
• Marvel at what you find.
• Replace the rock as you found it.
• Repeat.
  

Remember, your rock is likely someone's home. Be gentle, and if there are critters underneath, don't squish them when you replace it. It's better to move the animals to the side if you can, then replace the rock and let them scurry back.

If you'd like to share what you find with the rest of the rock-flipping community, here's how:

• Record it in still photos, video, sketches, prose, or poetry.
• Load images to the Rock-Flipping Day Flickr group, post observations on your own blog, or just leave a comment on this post. We'd love to hear about what you found!
  
• For anything besides a comment here, send a link to the coordinator, Susannah Anderson at Wanderin' Weeta, via email or a comment to her post on Rock-Flipping Day.

Whether you share your observations or not, you can check back with Wanderin' Weeta to see what everyone sent her. She'll collect all the links and post them in one place.

Now get outside and flip some rocks!

LOOK FOR: Goldfinches

Goldfinches are one of the most brightly colored common birds in the DC area. If you saw one in a tropical area, you might be transfixed...but here, it's just a goldfinch. Well, stop and let yourself be transfixed anyway. They're lovely birds.

It's the male goldfinch that's a showy yellow-and-black bird. The female is the same size and shape, but is much duller-colored. You'll often see them together in pairs (they're monogamous) or groups. During the winter, the males will molt and take on the duller colors of the female. They'll grow brighter feathers again in the spring in time for mating season, which is the real purpose of all that color, after all.

Unlike most birds, goldfinches rely almost entirely on seeds; they don't seek out insects for food at all. In fact, you could call them "thistle birds" -- the first part of the Latin name Carduelis tristis comes from Carduus, a genus of thistle found in Europe and Asia. (The species name, tristis, comes from the Latin for "sad," which makes no sense to me - anyone?)

Around August, the goldfinches start to regularly come to our yard to eat the seeds of our summer flowers. Among the flowers we offer, they seem to be particularly attracted to anise hyssop, purple coneflower, oxeye sunflower, and black-eyed susan. In the spring it also brings in the goldfinches when we let the kale and cilantro go to seed in the vegetable garden. Other flowers reported as attractive include milkweed, asters, and sunflowers. They'll also feed on grasses and the seeds of trees, including alder, birch, western red cedar, and elm.

Besides looking for the distinctive yellow markings, you can learn to listen for the song of the goldfinch. This video has a good example:

In the wild: Look for meadows on edges of woods. Goldfinches will feed on the seeds of the sun-loving flowers in the meadow (where you'll be able to see them better), but nest in the trees and shrubs.

In your yard: You can purchase birdfeeders specially designed for goldfinches, and fill them with thistle or nyjer seed. Squirrels seem less interested in these tiny seeds than in a typical birdseed mix, but be careful -- those plants may start growing where you don't want them from spilled seed. Goldfinches will also eat sunflower seeds out of a more typical birdseed. Or, just plant yourself a goldfinch garden with some of the native flowers listed above.

Like the photos in this post? Mouse over for credits; a click takes you to the photographer on Flickr.

More Butterflies: Wings of Fancy

Wings of Fancy is a walk-through exhibit at Brookside Gardens in Wheaton, MD, that allows you to be surrounded by hundreds of North American, Costa Rican and Asian butterflies flying freely inside a greenhouse. "Come witness the butterfly life cycle," says their website, "as tiny eggs hatch into crawling, chewing caterpillars, which then encase themselves in jewel-like chrysalides and emerge as sipping, flying adult butterflies." It's a great spot to try your hand at close-up photography, or just to sit and be delighted by the colorful creatures flitting by. You can also learn quite a bit about local butterflies, including the host plants that DC-area caterpillars rely on.

It's best to visit in the morning. Wings of Fancy is in a greenhouse, which is usually ten degrees warmer than the outside temperature, and more humid. The exhibit may close during extreme heat advisories or during emergencies. A telephone hotline (301-962-1453) and the web site are updated frequently in the event of a temporary closure.

Open: Saturday, May 2 through Sunday, September 20, 2009; 10 AM to 4 PM daily.

Admission: $6 adults; $4 ages 3-12. Children 2 and under are admitted free, but strollers are not allowed. Tickets are good for re-entry all day.

Location: Brookside Gardens South Conservatory
1500 Glenallan Avenue, Wheaton, MD 20902

The closest Metro station is Glenmont, which is about 1.3 miles away; the C8 bus runs between Glenmont and College Park stations, and stops about a half mile away at Randolph and Heurich. (From there, you'll go south on Heurich and east (left) on Glenallan to the park entrance.

More info: Wings of Fancy
"Butterfly Hotline": 301-962-1453
Brookside Gardens General Information: 301-962-1400

LOOK FOR: Monarch caterpillars (and raise them!)

The life cycle of a monarch butterfly is pretty amazing. And you can not only watch, but be a part of helping to make it happen.

Over the summer months in our area, there are multiple generations of monarchs. Adults mate and then lay their eggs on the leaves of milkweed plants. Caterpillars hatch from the eggs and proceed to devour as much milkweed as possible for the next two weeks or so of their lives, shedding their skin several times as they grow.

When they're ready, the monarch caterpillars will look for a good place to pupate, attach themselves upside down with a strong mass of silk threads, and shed their skins one more time. Their next skin hardens into a beautiful chrysalis, like jade decorated with sparkling gold.

Inside the chrysalis, the monarch pupa takes another two weeks or so to transform into a butterfly. The night before it is ready to hatch, you can see the butterfly inside: the chrysalis looks as if it has turned from green to black.

Early in the morning, the butterfly will split open its chrysalis, crawl out, and hang from the empty shell. It must pump fluid into its wings before they will stretch out to their full size. Here's a video we made a few years ago of the whole process as it took place in our kitchen:



Want to try your hand at it? To find caterpillars to raise, look for milkweed. Try looking along roadsides, the edges of playgrounds, or other "waste" places. Remember the caterpillars can be very small when they first hatch. They're probably trying to hide from you and the birds -- look on the undersides of leaves.

Before you bring any caterpillars home, make sure your schedule will allow you to replenish their food supply (milkweed leaves) every day or two. The leaves need to be kept fresh -- the best way seems to be picking whole stems and keeping them in water like cut flowers. We usually do this in a jar with holes poked in the lid, so the caterpillars can't fall into the water (we've drowned a few).

Your caterpillars will be so intent on eating that you don't have to do anything to cage them until the end of their larvaehood. But when they're ready to pupate, they will wander. We put ours in a small aquarium, and they attach themselves to the sides or the screen on top. You can also get a container made especially for raising butterflies.

Report back in the comments and let us know how it goes -- or share your own tips for raising butterflies!

Rainy Day Nature: Museum of Natural History

Sometimes, it's just not a good day to go for a walk. So we thought we'd do some posts on things to do when it's raining -- or just too hot to be outdoors all day.

The Smithsonian Museum of Natural History dates back to 1910. With 325,000 square feet of exhibition and public space, and more than 126 million specimens and cultural artifacts in the collection, you're sure to find something of interest. Our strategy is usually to pick two or so exhibits that we want to focus on; more than that, and our eyes start to glaze over.

Permanent Exhibits

The new Ocean Hall is now the museum's largest permanent exhibition. It includes many specimens of ocean creatures, videos, and a tropical fish tank that gets all the toddlers screaming "NEMO!!!". The sit-down movie on deep sea exploration is a nice way to rest your feet. And in one of the display cases on diversity, there's a video on squid camouflage that's pretty incredible. This place is full of sensory overload; you'll probably stumble upon other things that we missed entirely.

The Hall of Geology, Gems, and Minerals is home to the Hope Diamond as well as 3,500 other specimens including gems, minerals, rocks, and meteorites. We often think of nature as living creatures, but there's just as much of interest in the geological world, and the highlights are concentrated here.

The Insect Zoo is one of the things I still clearly remember from my trip to the museum when I was in second grade. This is indeed a zoo -- all the insects are alive, including pupating butterflies, honeybees coming and going through the wall of the museum into their enclosed hive, and tarantulas, which get fed three times a day. As you emerge from the insect zoo, there is a small butterfly enclosure that you can pay to walk through. It's free on Tuesdays. (There are also a few interesting displays on how butterflies and plants have co-evolved, which you don't have to pay for.)

Birds of D.C. is a permanent exhibit of stuffed birds whose living counterparts may be seen in DC. It's an opportunity to bone up on your bird ID and get a good look at some of the birds that are trickier to spot.

The Discovery Room has hands-on exhibits of fossils, skulls, shells, minerals, and microscope specimens, open for you to put your paws on from 10:30 to 3:30 daily except Mondays.

The Hall of Mammals includes stuffed specimens, skeletons, fossils, and an educational video about evolution under the somewhat corny, but kid-friendly premise of a "mammal family reunion." The animals come from all over the world, and give a sense of species diversity, but aren't as helpful for trying to learn about our local fauna. Similarly, there's a Hall of Reptiles.

Of course, the Hall of Paleontology is even less helpful in learning about modern, local animals. But it's still pretty cool.

Current Special Exhibits:

Farmers, Warriors, Builders: The Hidden Life of Ants is primarily an exhibit of really large photographs of ants. But not just any ants: ants that are fighting, farming, and dramatically affecting the environment they live in. There's a small colony of leafcutter ants set up in a contraption of gerbil tubes. More interesting, to me, was a metal casting of a fire ant colony, which at first we thought was just abstract art. Through October 10, 2009.

Dig It! The Secrets of Soil - We haven't made it to this exhibit yet, but it claims to be a "journey into the skin of the earth" in which you will "discover the amazing connections between soils and everyday life, and think about this hidden world in a whole new way." Cool. Through Jan. 2010.

LOOK FOR: Tiger Swallowtails

DC may be erupting in flowers, but there's something about seeing my first tiger swallowtail that makes me feel like it's really spring. In the fall, tiger swallowtails will form a chrysalis in which they'll spend the whole winter, waiting for the right time to emerge. And then, on some warm, sunny day in April or May, you'll see one fluttering by. And you'll know: winter's really over. In June, you'll start to see more. Summer's here.

Tiger swallowtails are large butterflies (they can have a wingspan up to 6 inches), and their black-and-yellow pattern is hard to miss. They have slightly different markings depending on whether they're male or female. The female has more blue on its bottom wings; males have little to no blue. (Just remember, blue is for...girls.) It must be this blue that Linneus was referring to when he gave this butterfly its species name, Papilio glaucus: "glaucus" can mean cerulean blue.

Remarkably, females can also be almost entirely black. There is some speculation that this might be mimicry of the pipevine swallowtail, which is much rarer in the DC area. It's also easy to confuse the black form of female tiger swallowtails with other black-colored swallowtails, such as the spicebush and black swallowtails. If you compare the two pictures on the right of the post, you'll see the edges of the wings are almost identical, but the blue is less pronounced. (Spicebush swallowtail has light blue, not yellow, spots on the edges of the wings; black swallowtail has more yellow on the wings.) They're all lovely.

In your yard: To attract tiger swallowtails temporarily, plant nectar flowers. But to really support them, plant one of their host plants -- which will provide the leaves the caterpillars need to eat. These include several trees; black cherry and tuliptree are favorites.

In the wild: You'll see tiger swallowtails in both woods and open fields. We've noticed they like to fly over trails and streams, perhaps because there are fewer obstacles. They sometimes will "puddle" in a sunny, muddy area, where they absorb minerals from the mud.

Sources for this post:

• Douglas Tallamy, Bringing Nature Home: How You Can Sustain Wildlife with Native Plants
• Amy Bartlett Wright, Peterson First Guide to Caterpillars of North America

Bookshelf: Bird ID

You would think not much could change in the world of identifying birds. The birds themselves don't change. But I still have my mother's copy of Peterson's Field Guide (2nd edition), complete with her parent's phone number on the inside front cover and notes from her college ornithology class in the margins. And I will tell you, we've come a long way from the days of those mostly black-and-white plates.

In this post, we'll review three current field guides to birds in our area. As a case study, we'll use a bird that was an occasional visitor to our condo's flower boxes in Dupont Circle: the house finch.

Peterson Field Guides: Birds of Eastern and Central North America (probably about 600 birds, 450 pages): This guide covers the birds you might expect to see in the US and Canada from the east coast all the way west to Texas and North Dakota. The shot to the right is from Matt's copy, which is a 4th edition; the 5th edition fixes one of our pet peeves about the book by adding small maps to each entry to show each bird's range. This makes it much easier to quickly exclude the birds whose range doesn't even come close to the DC area when trying to make an ID. The text is minimal, but provides basic descriptions of distinguishing visual characteristics, song, and habitat. The strength of Peterson's is that it typically shows at least 4 species on a single page; this allows for side-by-side comparison of similar species. In most cases the illustrations are clear. However, for several years, we had trouble applying the distinctions between the illustrations of the house finch (top right corner) and the purple finch (below it) to the birds we saw in front of us, and had an ongoing debate over which bird we were seeing.

The Sibley Field Guide to Birds of Eastern North America (650 birds, 432 pages): Sibley's covers about the same range as Peterson's, but makes several nice additions to the Peterson model. They still manage to fit about four birds to each two page spread, but by making the illustrations smaller, there is room for more information. Each description starts off with where you are likely to find each bird, which goes a long way toward settling our purple finch ("uncommon in woody and brushy areas") vs. house finch ("common and widespread in suburbs") dispute. The written descriptions of visual characteristics are associated with arrows to the relevant part of each illustration; this is much easier to follow than Peterson's method of stringing them together in a paragraph. Another nice bonus is a short section at the beginning of each group of birds (e.g. wading birds, raptors) with general information and comparing the genera or species within the group. Unfortunately, these sections don't really stand out as breaks; it's easy to skip over them as you're flipping through the guide.

Smithsonian Handbooks: Birds of the Mid-Atlantic (328 birds, 400 pages): This guide focuses on a smaller geographic range (VA/WV through NY/NJ), and thus has room for a full page per bird. The benefit of this approach is much richer information about each bird, including notes on behavior, breeding, nesting, flight patterns, and what they're attracted to in bird feeders. The downside is that you lose the ability to compare birds side-by-side: you have to turn a page between our purple finch and house finch (we pasted them together here). The book tries to make up for this by including a small inset on each page about similar birds, but it's not as easy to use. This guide uses photographs instead of illustrations, which is helpful in the case of our finches. If the pictures are accurate, it's clear we never saw a purple finch at our flower boxes. In general, the photos are a mixed bag: some more difficult-to-photograph birds are a little blurry or in odd poses. And the photo of the great egret, a pure white bird, looks largely grey from a shadow. Failing to at least Photoshop that shot seems like a major oversight. One other drawback in this guide is that unlike the other two books, there's no label like "hawks" or "ducks" in the upper corners of the pages to help you flip to the right general area as you narrow down your search for a bird.

Bottom line: I think it might be time for us to move beyond Peterson's. Sibley's gained another edge last week when it was the only book of these three that clearly identified a juvenile starling (which is grey, instead of black like the adults). It had a clear picture and also an apt description of it "waddling," which was a clincher for my confidence that I had made the right ID. But I keep going back to the Smithsonian book, as well, for the longer descriptions.

Do you have a favorite field guide? What do you like about it? Click below to leave a comment.

LOOK FOR: Fireflies

One night many years ago I looked out over a field dancing with fireflies and I had a realization: this is why people believed in fairies. I must have been thinking of Disney's Tinkerbell and her trail of twinkling pixie dust, so much like the swooping, twinkling light of the fireflies. Or J.M. Barrie's description: "when the first baby laughed for the first time, its laugh broke into a thousand pieces, and they all went skipping about, and that was the beginning of fairies."

But those dancing lights aren't fairies. They aren't flies, either: they're beetles, actually. In the light of day, they look like nothing special: black beetles, sometimes with a red head. The exact looks of a firefly depends on the species; there are 23 genera and about 200 species of fireflies in North America.

The different species also have different flashing patterns at night. (The Museum of Science, Boston, has an animation that shows what to look for to tell the difference.) Some come out at dusk; others wait for more darkness. Some are high in the trees; others are closer to ground level. They also may flash different numbers of times, with different duration, and flying in different patterns while they flash. That way, they only seek mates of their own species. Unless, that is, they've been tricked by an impostor in the genus Photuris, which mimics the flashing patterns of other fireflies to lure them in and eat them.

When they're done mating, female fireflies lay their eggs in the ground or in rotting logs. The larva of a firefly looks like a grub, and eats other insects, as well as worms, snails and slugs. The larvae -- and the eggs -- can glow in the dark. This gives the family of fireflies their name: Lampyridae, from the Latin and Greek words for "glowworm." One theory is that the green glow is a warning sign to predators that these larvae don't taste good. Apparently, the adults don't taste good either.

But humans don't care what they taste like. And so we like the dancing green glow: as a sign of summer, as a memory of childhood. Or as a glimmer of hope that fairies really do exist, if we only believe.

In the wild: Different species like different habitats, but a good bet is to look at the edge between forest and open field. They also seem to like to be near a source of water. The picnic areas at Rock Creek Park are probably ideal.

In your yard: Even when we lived in a 6th floor condo in Dupont Circle, we could see fireflies in the street trees. But there are some things you can do to help attract and protect fireflies in your yard, if you have one:

1. Habitat. Because they spend a lot of time on the ground during the day, fireflies may be harmed by lawn mowing. In addition, lawn pesticides aimed at grubs may kill firefly larvae, which also live in the soil. This is just one more reason it makes sense to avoid spraying your lawn, and let it grow to at least 3 inches before cutting. Better yet, consider replacing some lawn with plants that do not need to be mowed.
2. Darkness. Some scientists think outdoor lights and streetlights may interfere with fireflies' ability to communicate and find mates. You may have a better show if you leave your outdoor light off.
3. Research. The Museum of Science, Boston asks people to report their observations of fireflies once a week throughout the summer, to learn more about firefly distribution and behavior. Sign up at Firefly Watch.
   

Also this week:
The mulberries are still dropping, but honestly, with all this rain, they're pretty tasteless. The serviceberries are probably also still going.

Sources for this post:
Firefly.org
Museum of Science, Boston

Have you started seeing fireflies yet? Do you have a favorite place to watch them? Leave a comment.

Local Nature in the Media

Wilson bridge open to pedestrians and bikes: the consensus seems to be that the view is great, but once you're in Maryland, it's hard to bike much further. See this Post article and a damning review of National Harbor's readiness for the non-car traffic at Greater Greater Washington.

Hawks are nesting on the Rayburn Building: The Post's John Kelly takes a walk with a Hill birder to see the hawks (with a great picture) and whatever other birds they can find.

Beavers have rebounded, but not everyone is happy: The beaver population in North America has rebounded from 100,000 in 1900, to 10-15 million today, possibly close to original levels. This NY Times article is primarily about clashes between homeowners and beavers in Massachusetts, but makes reference to their comeback in DC as well. Bottom line: in humans vs. beavers, beavers often win.

Beauty of the Chesapeake: The Washington Post Sunday Magazine ran a gorgeous set of aerial photos showing both pristine nature and the human footprint on the Bay. It was accompanied by an essay asking, can we stop ourselves from destroying the Chesapeake Bay's natural wonders?: "The Chesapeake was alive with crabs, sturgeon and rockfish. Oysters grew on oysters, in reefs so big they broke the surface of the water. The bay's bounty, which helped sustain Native Americans for centuries, seemed endless...Some fear that eventually the bay may be pushed beyond an invisible point of no return -- that even if we finally muster the will to mend our ways, we'll find that the crabs, oysters and underwater grasses are so depleted that they can't return. "

Ghost Deer and Other Miracles of the Northwest Branch

We went out to the Rachel Carson Trail on the Northwest Branch (just upstream of Colesville Road) this weekend to get one last look at the mountain laurels before their flowers fade. We went in the evening, hoping to see more critters around sunset. But we never expected this.

First, the cool stuff we did expect: We checked on the wood thrush nest we discovered a week and a half ago, and one of the eggs had hatched, with one of the scrawniest, ugliest, most miraculous little baby birds I have ever seen. We didn't see the piliated woodpeckers at the nest we spotted last time, but further down the trail, we saw downy woodpeckers flying to and from their nest repeatedly, and we could hear the babies inside squawking. The tadpoles in the frog pond are getting their legs -- and we found some crawdads in there too. We stopped to watch the sunset on a hillside of mountain laurels. And after the sun was down, we walked back to a beaver dam to see if we could spot a beaver before the light completely faded.

There was no beaver. But on the way to the dam, we saw several groups of deer browsing. And, when we reached the dam, standing only a few feet from the trail, was an all white deer. In the fading light, the four deer it was with were harder and harder to see, but the ghost deer stood on the hillside, glowing, and looked at us for quite a while before it walked up and over the hill.

I'm reminded of the legend of White Buffalo Woman, who is supposed to return four times in the guise of a white buffalo and usher in an era of peace and understanding, if we're ready for it. Apparently there are also legends about white deer: for the Housatonic Indians, the killing of a white deer by a French military officer led to an era of wars, blights, and displacement. (I'm not sure the deer was really the problem, but the symbolism is potent).

A Chickasaw story follows the classic storyline of a father asking an impossible price (a white deer) before a suitor can wed his daughter. The suitor never returns, but the daughter never marries, because she sees a white deer every full moon in the smoke of her campfire.

But this was no campfire. It was right there in front of us. Right on the Northwest Branch of the Anacostia.

LOOK FOR: Baltimore Orioles

If you live in the DC area, you've seen a Baltimore Oriole. They're on all the sports paraphernalia. But have you ever actually seen one?

The Orioles logo is, surprisingly, a fairly good estimate of what you're looking for: a bright orange breast and shoulders, with black head, back, wings, and tail. The males are generally a brighter orange than the females.

Orioles migrate to Florida, the Caribbean, and Central America for the winter -- we saw one in Guatemala one February. They come back to this area to breed every spring. And right now, they're building their nests. And the nests are remarkable: rather than resting on top of a branch like most birds' nests, orioles' nests are a long sack that hangs down from the branch.

Orioles often hang out in treetops, which can make them hard to spot. This time of year, you might find them drinking nectar from a tuliptree, or nesting in a sycamore. Because they're so high up, though, the easiest way to spot them is to listen for their distinctive song, then try to find the singer with a pair of binoculars.

Try listening to this recording of the song several times before you head out this weekend, and see if it helps you find one. You may realize they've been in your neighborhood all along.

In your yard: Some people say leaving out fruit will attract orioles, but I've never gotten it to work -- the squirrels run off with it first. What did attract a pair of orioles right down to ground level in our yard several times this week was nesting materials: we left out a pile of old flower stalks broken into pieces, and various birds have been coming to the pile for weeks.

In the wild: Orioles like forest edges more than dense forest. We've seen them in sycamores along Rock Creek and along the Potomac. For a bird's eye view, try stopping for a look if you're crossing one of the high bridges (e.g. Calvert St.) across Rock Creek, or try the bluffs at Scott's Run.

More info:

Cornell Lab of Ornithology

Smithsonian Migratory Bird Center