Friday, December 28, 2007

Ringing in the New Year


The woods are never completely silent. On cold winter days, you won’t hear buzzes or clicks of insects, or the flute-like song of a wood thrush… but you can hear dried leaves rustling in the wind, water flowing downstream, woodpecker taps and calls, and warbler songs. That’s right. Warbler songs.

You see, bird vocalizations can be categorized as ‘songs’ or ‘calls.’ Songs are almost exclusively performed by the males to establish and maintain territories for breeding. The songs function to simultaneously ward off competitors and attract mates. Calls are simple notes or phrases uttered by males and females to communicate the availability of food, presence of predators, or relative distance from the receiver. Since true bird songs are reserved for breeding season activities, even year-round residents have nothing to sing about in the winter months. Or so you would think.

Pine Warblers set up their territories, mate and breed earlier than most other birds in the forest. In Louisiana, they start singing in the winter, and are nesting by the middle of March. So, on a sunny New Year’s Day at Walter B. Jacobs Memorial Nature Park, the forest rings with the tremulous trills of male Pine Warblers singing in the canopy.

Listen to the Pine Warbler:
Find good information about the Pine Warbler:
http://www.fs.fed.us/conf/birds/Pine_Warbler_MIS_New_Plan.pdf
conserveonline.org/docs/2001/05/piwa.doc
http://www.birds.cornell.edu/AllAboutBirds/BirdGuide/Pine_Warbler_dtl.html

Thursday, December 20, 2007

Peepers in December


The breeding song of the Spring Peeper heralds the spring… in Vermont! Here in Louisiana, peepers fill the December night with song. Just as the deciduous trees close up shop for the year and the wintering birds arrive, cold autumn rains revive the vernal ponds and the peepers begin their chorus.


Almost always heard and not seen, these diminutive frogs are only about the size of a nickel. They spend their days sleeping under logs and in leaf litter on the forest floor. They awake in darkness, and spend their nights eating ants, beetles, flies, spiders… whatever’s available… whatever fits in their mouths. Their cryptic coloration affords them some protection. Still, many fall victim to salamanders, snakes, owls, and larger frogs.


Those that live long enough (3 years) will congregate in the temporary ponds. The males establish small territories and call. The louder, faster callers succeed in attracting females for momentary trysts. Fertilized females then deposit their eggs – one at a time – under vegetation and debris on the bottom of the ponds. Each female lays 900 or so eggs before retiring to higher ground. In four months, her offspring – whom she will never know – join her on the forest floor.

Where will the peepers live when the forest is gone? Where will they breed when their habitat is commandeered for a housing development, and their ponds are filled with soil? Those that inhabit protected areas like the 160 acres of Walter B. Jacobs Memorial Nature Park may not have to find out.

Tuesday, October 30, 2007

The Night Flier


High in an old pine tree, in an old woodpecker hole, a southern flying squirrel lies huddled with his family. He wakes to a reveille of silence - the pause between the canticles of the day birds and the acoustic strums of crickets and frogs.

Eager to break his fast, he crouches on the edge of his doorway and dives. Freefalling, he flattens his tail and steers his body onto the vertical surface of a tree. He grabs hold and hurries to the opposite side, looking back to be sure his path was not tracked. Throughout the night he flies and lands, always circling around the tree to elude owls, foxes, minks, raccoons, snakes, and others who would eat him.

An accomplished acrobat, he prances along a horizontal branch high above the forest floor. He knows his territory. He knows every available cavity and refuge. When the alarms sound that a predator is near, he can quickly take cover. Now, the chirps and squeaks from his fellow flying squirrels assure him that all is well in their own sections. He, too, twitters and chips, reporting the semblance of safety in his vicinity.

In the next twelve hours he will feast on a banquet of lichens, fungi, seeds, and berries. He will raid rodent nests and devour the infants alive. On shorter, warmer nights, he might steal and eat bird eggs and even baby birds. Now, the growing darkness and falling temperatures prompt him to hoard and hide acorns and pecans. Some he will bury under leaves on the floor. Some he will deposit in communal caches in the cavities of trees.

Before his next jump he expels the baggage from his bowels. The jetsam contains spores and seeds which will grow into new organisms. The fungi he disperses are vital to the forest, fixing nitrogen in the soil so that it can be absorbed by tree roots. The seedlings he plants are equally important. They feed browsing animals and renew the forest.

The pre-dawn intermission in Nature's symphony cues him to return home and rest. He has survived this night and will live to fly again.

Saturday, September 15, 2007

Today's Visitors

Let me see if I can illustrate this scene for you…

1:05 p.m. Two men drive into the nature park, pass the parking lot and park directly in front of the building. This behavior indicates that 1) they have some varmint they want to identify and/or relinquish custody of, or 2) they are unwilling or incapable of walking very far. In both cases, the visitors will exhibit common behaviors once inside:

∙They begin with the mildest curiosity about the exhibits inside the building.

∙They become slightly more interested as they discover the other rooms.

∙They will express fear and/or disdain for some (if not all) of the animals on exhibit.

∙They will absolutely not want to walk or hike and have no use for a trail map and probably don't want a brochure.

∙They will spend no more than 15 minutes in the building, including the time they spend in the restroom.

The men are around 60 years old, and one has an obvious limp. He makes a bee-line for the restroom. The second man remarks about the attractive dioramas. "Those were created by Don Edwards," I say and pause for moment to see if the name means anything to him. [Don Edwards is a locally renowned wildlife artist who painted the 1994 Louisiana Duck Stamp, a mural that covers the entire wall of a building in Downtown Shreveport, and lots pieces often displayed at the Shreveport Regional Airport.] He knows of the artist and can't say enough good stuff about him.

"Did you know that he puts a little Red-headed Woodpecker in every painting he does? It's fun to try and spot them." The man seems to take little interest in this tidbit. He looks up at the taxidermic owl.

"What kind of owl is that?"

"He's a Barred Owl…"

"Oh, a Barn Owl?"

"Barred. He's called that because of the stripes on his chest that look like bars…"

"B-A-R-D?"

"B-A-R-R-E-D."

"Is this the kind of owl I hear at night?"

"Where do you live?"

"North Highlands."

"You could be hearing him. There are three owls that you could expect to hear around your neighborhood…the Barred, the Great Horned, and the Screech. This one, the Barred Owl, says 'Who cooks for you; who cooks for you all?"

"That's him!"

"There's another owl who hoots," I say, leading him to the taxidermic predator-prey display in the next room, "This owl, the biggest we have, the Great Horned Owl."

"How does he sound?"

"His voice is lower, and he usually has only 5 syllables: 'Who's awake? Me too."

He thinks he's heard this call, too.

"This is the owl that you hear on television when it's supposed to be nighttime on the show."

The man with the limp enters the room. "Hey! I know what that owl is around my house…it's a Barred Owl." He turns to me, "Tell him what the Barred Owl says again."

"'Who cooks for you; who cooks for you all?' They call to announce their territories and attract a mate. Sometimes the mates will 'talk' back and forth with each other; they don't always do the whole call, and sometimes they add notes on the end."

"Do this one. The Great Horned Owl."

"'Who's awake? Me too.' The phrase helps me remember that their voices are lower and they usually have 5 syllables, 'Who, who who…who who.'"

"What's that other owl you said we might have?"

"The Screech Owl. He doesn't hoot. He sounds like a tiny horse whinnying from the trees," and I do my best to imitate the sound.

"Yeah. I've heard that before, too."

The interaction seems to have run its course and I want to remove myself so they can explore on their own. I remind them to let me know if they have any other questions. Before I can take a step, they ask me about the alligators… and then the turtles. I move out of the room with them and once again, before I can walk away, they have more questions…

"You said there was other rooms?"

"Yes." I lead them to a third room. "In this room we have leaves of trees that are in the park, a slide show of the butterflies known to be in the park, and a few of the snakes."

We discuss the snakes (how they eat, who feeds them, who cleans their cages, their microhabitats, etc.). We move back into the main room to see the other snakes.

The man with the limp looks out the picture window and sees a squirrel at the feeder. "We got to go!" He says hurriedly, "We got to pick up this car over on North Lakeshore."

As I walk with them toward the door, I thank them for coming and invite them to come back, but we don't get far…

"Hey! Have you seen this? Don Edwards did this."

"Yeah?"

"And he paints some kind of bird in all of his paintings…"

"A heron?"

"No. It's something in the tree. What is it again?"

"A Red-headed Woodpecker."

"Where's it at?"

I give them instructions on where to see the bird. "He's up high on the trunk of the third tree from the corner here, about two inches above the leaf of that bamboo." They can't see it. After a second, I think to get my binoculars. "Maybe we can see them with binoculars."

Can you visualize this? Inside a building inside a nature park, the three of us cluster together, and share binoculars to get a view of a 1 centimeter-tall painting of a Red-headed Woodpecker on a wall. It was almost like we were really birding!

On the way out the door, the first man asked me about the 'owl thing' he heard about here at the park. He had thought his granddaughter might want to come, but she was scared. I got him a pamphlet listing all the events we have planned for the year. I explained what the Owl Prowl was and when we would be doing it again.

"Thank you." "Thank ya'll for coming. Have a nice day." "You, too."

They leave at 2 o'clock.

Tuesday, September 11, 2007

Spider Webs


I crash through and inadvertently destroy countless spider webs on my treks through the forest - but there's one web I don't blindly blunder into - the web of the Spiny Orb Weaver, (Gasteracantha cancriformis). Her web is easy to see because she thickens every fourth centimeter of the frame and support threads with extra silk. Surely, the Spiny Orb Weaver does this out of instinct and does not know that in doing so she is outlining her web with caution tape. There is definitely an advantage to this behavior: Upon completing my 1.5 mile walk this Friday, there were 23 in-tact spider webs in my wake - 23 Spiny Orb Weaver webs. That's got to count for something!

Tuesday, September 4, 2007

Two Trails

As often as I can, I explore the Ouachita and Adai Trails at Walter B. Jacobs. Their combined length is very nearly 1.5 miles. Though both trails are in the same patch of woods in the same little nature park, they have distinctions:

The first two-thirds of Ouachita is flat. The trail is frequently under water. The under story is sparse. After it digresses from the Caddo Trail, and passes another path leading toward Caddo, it turns west and follows Fordney Bayou. As the trail creeps closer to the bank of the stream, the vegetation gets denser. Just before the concentration of Paw Paws and Spicebushes, there is a bench. This is where I sit. I listen to the Acadian Flycatcher, Yellow-billed Cuckoo, Summer Tanagers, Flickers, Pileated Woodpecker, and Downy and Red Bellied Woodpeckers. I have to tune out the chorus of cicadas, and often the screams of the American Crows as they announce the presence of the Red-Shouldered Hawk family - who screams back. When the chickadees and titmice join the cacophony, I have trouble singling out and identifying species. I am occasionally harassed by this dangerous-looking hymenopterid, and though I don't know what she is, exactly, I'm pretty sure she wants me to move along. So I do. Then I come back a few minutes later.

I'm here for the Paw Paws, and the Zebra Swallowtail butterflies they host. I have had very little success finding caterpillars and chrysalides. I saw the spring flight of adult butterflies, but then I missed the summer flight while busy with Earth Camp. Now I await the final wave of Zebra Swallowtails for the year.

Bayou banks and Paw Paws are features Adai has in common with Ouachita. Adai parallels the western bank of Fordney Bayou, passes the Yatasi Trail, and then turns west and south and follows Shettleworth Bayou. Adai is on higher ground, and climbs, peaking just passed the intersection with the Miracle Trail. Then it plunges down to the edge of Shettleworth. The three oldest Paw Paws are on this slope. The trees reproduce vegetatively by sending sprouts upward from horizontal roots, so the number and size of individuals are greatest at the center, and then decrease away from the center in a radial pattern. I've seen flowers on the three trees, but not fruit. I suspect they were quickly devoured by gray squirrels, opossums, raccoons, or gray foxes. So, I think the seeds get dispersed, too.

Adai continues to follow Shettleworth Bayou, through a second colony of Paw Paws, past the other side of Yatasi, and on until it converges with Caddo. It then turns left again. This section is low, like Ouachita, and like the area around Ouachita after the bench, it is surrounded by ephemeral ponds, Louisiana Palmettos, and Giant Cane. Interestingly, I have found no Paw Paws here. There is another Acadian Flycatcher over here. After two foot bridges, Adai crosses a big bridge over Fordney Bayou and unites with Ouachita. From here on, the one path has five trail names: Ouachita, Ozark, Adai, Caddo, and Miracle.

I spend approximately three hours on this figure-eight. I prune limbs and vines, and remove debris from the trail, but I use most of that time to look and listen. I could spend longer, but the lure of mosquito-free indoor plumbing calls me back at about that time.

Thursday, August 30, 2007

A Simple Food Chain

I have a beautyberry bush (Callicarpa americana) in my yard. I think it is comprised of more than one individual. I think I remember planting more than one. I wish now, as I look as the thick tangle of stems and downward-curving branches, that I had planted them farther apart. I got those plants from the side of a dirt road in Doyline. I was bird-watching, and had ventured down the road which I knew ended at a little open space at the edge of Lake Bistineau named "Tadpole" by the locals. The right fork of the road went to Tadpole; the left fork went to a really big house that was visible from Tadpole. Folks said that house belonged to Coach Roach's brother. Folks also said Mr. Roach didn't like people on his road.

I'd been to Tadpole dozens of times when I lived out there. I never saw anyone come or go on that road. Before this day, I'd always been on foot, and I never felt like walking an unknown distance to see a house that supposedly belonged to a mean hermit. But this day I was riding in a truck, so when we reached the fork and discovered that the path leading to Tadpole was overgrown and impassable, we decided to venture down Mr. Roach's forbidden driveway. The forest edge created by the dirt road made for incredible birding. We crept slowly down the road, stopping every so many yards to listen for something new. We got to the end of the drive to see an electronic gate, and beyond it the biggest house I've ever seen.

Seeing three cars parked up at the house, we figured we'd soon be explaining to someone what we were doing there, so we pulled to the side of the drive and continued pishing, kissing, and broadcasting a recording of a never-ending Screech Owl call in an attempt to illicit mobbing behavior from unsuspecting birds. Another vehicle came down the road and entered the gate. The driver waved to us as he passed. He came back out a few minutes later, and passed us by, waving again. Not long after that we decided we'd counted every bird we could from that location, and began to drive out. Going slowly so as to hear if something new was singing, we spotted some beautyberry sprouts right at the edge of the road. I got out and pulled a few plants up with my hands. I put the roots in a soda bottle with a little water, and went on with my birding adventure.

I planted the beautyberry that evening. I remember the stem of the biggest sprout had snapped and even though I thought it was lost, I tried to mend it with scotch tape. Three years later, I can still find the stem with the scotch tape bandage. The plants are loaded down with berries. The weight of the berries causes the branches to sag, giving the bush a sort of fountain-spray appearance. The mockingbird whom eats there daily finds it difficult to stay on the branch as he forages. He often falls, and catches himself on another branch, falls again, and so on and so forth until he either has had his fill of berries, or tired of the Mr. Bean routine. I don't know which.

I planted those plants specifically because I wanted birds to have berries to eat. I am happy when I see the mockingbird coming to the bush, but I'm also a little happy when he falls down…because I think he ate my Spicebush caterpillars.

I had collected two Spicebush Swallowtail caterpillars and brought them to live on my spicebushes. I observed them daily (and nightly, since I read that's when they eat). I watched them morph from small blobs of bird droppings into green freaks with giant false eyespots. I watched them change from green freaks with giant false eyespots to orange freaks with giant false eyespots - one a day earlier than the other. And then they disappeared - one a day earlier than the other. I had hoped they had gone off to form their chrysalides. But when I saw the mockingbird shopping around my little spicebushes, I feared my little caterpillars had been somebody's dinner.

So I have mixed feelings about my neighbor the mockingbird. And I'm having second thoughts about the beautyberry's role in my 'landscaping plan.'

Friday, August 10, 2007

Chiggers

As a child I found lots of natural areas to explore right here in Shreveport. Some of them - like the Stoner Woods - I was forbidden to enter because caring adults feared the threat of strangers. (I did venture in there once, as an adult, accompanied by a dog, and I quickly discovered that my parents' concerns had merit.) Anyway, while in Shreveport, I enjoyed a happy medium between having woods to play in, and having friends to play with.

As you may have deduced from the foreshadowing, I did have to leave Shreveport during my childhood, and I was not a happy camper. We bought a nice house in Doyline for a ridiculously low price (location, location, location). I was forced to change schools, and convert my best friends into pen pals. The town of Doyline was picturesque enough, and there were two schools (K-5, and 6-12), but our house was two miles from those schools. Our house was also two miles from the nearest store. There was no park. The library was a single room building among the antique store fronts on the one road in town. It was only open one day a week for a few hours.

I scanned the houses and trailers for any child my age. I found none. As to add insult to injury, the really cool log-cabin house was surrounded by a desert of turf grass.

Overgrown turf grass.

(The trees were somebody else's property. Of course, I know now that the woods in Shreveport were somebody else's property, too, but back then, I had never before considered that somebody owned - or could own - the woods.)

The first day my family stayed in that house, my whole family was plagued with bug bites. My whole family...except for me. At first, my parents were convinced that they had been swarmed by mosquitoes. These country mosquitoes, however, went for skin covered by snug cloth and elastic bands. After two or three days, they were still miserable, as the bumps on their skin were still itchy, red, and swollen. Worse yet, good ole' calamine lotion gave them no comfort.

I couldn't help but think in was karmic: The people who forced me to leave civilization were now driven mad with some kind of skin parasites they encountered at their country paradise. But meanness aside, I held the biggest clue to the problem...I did not have any bites (or whatever they were).

So let's use deductive reasoning: The itching bumps appeared on Tuesday on three people, but not the fourth. On Tuesday, all four family members crossed the front yard, brought in boxes, and dwelled in the house. Three people ventured out among the tall grasses to explore their new backyard. The fourth walked the road following the woods to find a property owner. If the fourth person acted as a control, then the variable of the experiment is the overgrown grass - the one place the fourth person did not go.

Serves them right. Stupid grass.

But seriously, whatever they encountered were obviously not mosquitoes. They were...as we were about to learn from the locals...chiggers.



Chiggers are little bitty red mites that have a parasitic stage of their life cycle. You may actually be able to see the adults (harvest mites) if you sense movement well and look really hard. The larvae walk so lightly that you don't feel them on you, but once they pierce your skin and inject you with a salivary secretion, you'll feel them alright! The secretion contains powerful, digestive enzymes that break down your skin cells so that the chiggers can ingest them.

To board a host, chiggers climb up plant stalks and wait for something or someone to brush by. They only hang around for about four days, then drop off to complete the rest of their life cycle as upstanding members of the environment. Sometimes the skin remains irritated for a few days after the parasite has gone, but the itching that results from having microscopic quantities of your skin liquified and sucked out is incredible. To alleviate it, people have come up with all kinds 'remedies.' Paint the bumps with nail polish, pour rubbing alcohol on them, bathe in oatmeal, bathe in bleach, coat your skin in oil - you name it - someone has probably tried it.

During my family's first days at the new house, I escaped a chigger infestation, but I have not always been so lucky. I have had my share of chigger bites. I have also tried many of the home remedies. I seem to remember a product called "Chig-a-rid" that I painted over the bumps. It definitely worked better than nail polish. Not too long ago, I took my chiggers to the dermatologist. I thought it was high time to get some professional advice and prescription-strength products. I was surprised to discover that the dermatologist's advice was to add one cup of bleach to a hot bath and soak. "You can tolerate it," she said, "They can't."

http://ohioline.osu.edu/hyg-fact/2000/2100.html

http://www.chigarid.com/

Friday, June 1, 2007

Warning Colors

I thought I understood well how warning colors function in nature. It makes perfect sense to me that a blue jay – new to the world – would sample a monarch butterfly. And that after vomiting and feeling quite terrible, he would choose not to eat any more of those orange and black-striped critters. I understand that the blue jay’s experience didn’t help the individual monarch whom he ate, but does benefit the monarch’s relatives within the jay’s territory.

It is also easy to see how a bobcat might approach a skunk, have a negative experience, and learn from it. In fact, I can find innumerable examples of how warningly colored animals teach predators a lesson they will not likely forget.

But what about that coral snake? One can’t learn every lesson first-hand. If a coyote tries to eat a coral snake, it may not survive the experience. Who would that be a lesson to? No one. Unless you want to try to convince me that the coyote had an audience, and that the onlooker learned to avoid coral snakes vicariously.

In The Birder’s Bug Book, Waldbauer speculates that it is possible that the coral snake actually mimics some other, less venomous snake. He supposes that the coyote encounters the other red, yellow, and black snake, and is assaulted with some mild venom. By the time he sees a coral snake, he knows to avoid the aposematic colors.

That’s a thought.

But what is that other snake? This snake would have to be nearly every place the coral snake is…from North Carolina to Argentina. There are 52 kinds of snakes in Louisiana. There are 5 venomous snakes besides the coral snake: pygmy rattlesnake, copperhead, cottonmouth, timber rattlesnake, and eastern diamond-backed rattlesnake. None of these contestants could win a coral snake look-alike contest.

So here’s what I think: Snake-eaters don’t learn to avoid red, black, and yellow rings. They are born with the instinct to avoid those colors. Add this behavior to hundreds of others that we already accept as instinctual (from how sea turtles get back to the same beaches where they started their lives to lay their eggs, to how my dog always makes three circles before lying down), and doesn’t it just make sense?



http://links.jstor.org/sici?sici=0003-0031(198004)103%3A2%3C346%3ARONTBT%3E2.0.CO%3B2-I



http://www.amazon.com/Birders-Bug-Book-Gilbert-Waldbauer/dp/0674002067

Tuesday, May 29, 2007

Host Plants



I found this caterpillar on the Ouachita Trail at Walter B. Jacobs Memorial Nature Park. I was inspecting Paw Paw (Asimina triloba) leaves for Zebra Swallowtail caterpillars.


I have read that Zebra Swallowtail caterpillars eat only leaves of Asimina species. I have read that Paw Paw Sphinx caterpillars eat only Asimina species. I have read that there is this pyralid moth with no common name (Omphalocera munroei) that eats Paw Paw leaves so voraciously that it defoliates the trees in the middle of the summer, stimulating the trees to grow new leaves, providing the last generation of zebra swallowtail caterpillars with an unusually abundant food supply, and thus is responsible for increasing the population of adult Zebra Swallowtail butterflies that fly in the fall.


I discovered a folded Paw Paw leaf, and pried it open to peek inside, curious to see if I had found a Zebra Swallowtail caterpillar, or a Paw Paw Sphinx caterpillar, or the never-seen-by-me O. munroei. I found this. It's a Spicebush Swallowtail caterpillar. As you might guess Spicebush Swallowtail caterpillars eat Spicebush (Lindera benzoin). They are also known to eat Sassafras. Some sources say they will eat Sweet bay, Swamp bay, laurels. Caterpillars in the Field and Garden say the Spicebush Swallowtail caterpillar "lives in folded leaf shelters on the host." ON THE HOST.


That's a Paw Paw leaf I'm holding. So did I just find another host for the Spicebush Swallowtail?












[By the way, the Zebra Swallowtail caterpillars seem to stick to the underside of the Paw Paw leaves. I have discovered that curled Paw Paw leaves most often conceal little jumping spiders.]