Frog Calls February, 2013

Page 1

Frog CallsNewsletter of Crosstimbers Connection

v Volume 1, No.1 v February, 2013 v

Welcome to “Frog Calls”!We are glad you are reading this issue of Frog Calls, the newsletter of Crosstimbers Connection. In these

pages, we’ll tell you what we have been doing, and what we plan to do. We hope you will plan to join us

for a field trip! We will also include some stories about the wonderful places and animals found in

north Texas.

Who is Crosstimbers Connection? We are a small

nonprofit organization started by people who have spent many years in the woods, creeks, and forests of

north Texas. Several of us have served for years with

the Dallas-Fort Worth Herpetological Society, going on field trips and providing educational events for

the public. We believe that spending time in nature is exciting and fun, and that we can learn a lot about

the world around us when we go for a walk in the woods. To ask about one of our field trips, just

contact us through our website.

Frog Calls can be downloaded from our website,

www.crosstimbersconnection.org, or it can be emailed to you if you let us know you would like to

get it.

Reptiles Up Close

On February 23, we took our stories, photos, and some harmless reptiles to Riverside Community

Center in Fort Worth, to the Get Outside Fort Worth (GO FW) club. There were lots of slides of some

beautiful prairies, woodlands, and wetlands, along with equally beautiful slides of the reptiles and

amphibians that live there.

We talked with thirteen kids and six adults, and

started making some plans for a follow up field trip to the Fort Worth Nature Center and Refuge. Jocelyn

Kids at the GO FW club learn about the nature of north Texas

Continued on page 2

Jocelyn and her dad check out a three-toed box turtle

Frog Calls February, 2013

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and her dad got a chance to meet a three-toed box turtle. Mark Pyle showed them this shy turtle, which

stayed mostly closed up in its shell. Andrea and lots of other kids enjoyed seeing a speckled kingsnake

and several other harmless snakes. Mark also showed them a glass lizard, which is an unusual

lizard that has no legs and moves around somewhat like a snake.

The GO FW program is a free family nature club that provides monthly informal outings where

people are welcome to come and go as they please. (To contact the GO FW program, call

817-871-7670)

Reptiles Up Close, continued

Andrea makes friends with a speckled kingsnake

The Web of Food that Supports Life

It all started with grass. Fresh, new shoots of the kinds of grasses that grow on the prairie. Grasses

with names like bluestem, indiangrass, and sideoats grama. And because of grass and other green plants,

a hawk soars in the skies of north Texas. And also because of these grasses, a bullsnake cruises along

the prairie at sunset in the last rays of sunlight.

In fact, maybe we should say that it all started with

those rays of sunlight. After all, it is the energy in sunlight that green plants use to make food for

themselves. Then if we eat the plant, it becomes our food. We eat spinach, squash, carrots, and other

plants to get the food they created using sunlight. And lots of animals, like rabbits, grasshoppers, or

deer, eat plants as a source of food.

Some of those prairie grasses were eaten by a grasshopper. A little, green grasshopper that was just

a little too slow. If it was faster, it might have hopped away from the whiptail lizard that thought it would

make a tasty treat. As it was, the lizard pounced on the grasshopper and ate it. It ate dozens of other

insects that day, and since each insect had stored the energy from the plants it had eaten, the lizard was

benefiting from all that food created by the bluestem and the indiangrass.

Nearby, a couple of northern pygmy mice were nesting under some old cactus pads from a prickly

pear cactus. These little gray mice had grown up on a diet of plants, and they especially liked small

seeds. It also happened that a western coachwhip

Michael Smith

Frog Calls February, 2013

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snake was prowling around the area,

looking for food. This long, slender

snake had large bright eyes and

would raise the forward part of its

body from time to time and look

around, flicking its jet black tongue

out to pick up a “taste” of its

surroundings. It used everything it

could see and smell to know if

food - or danger - was nearby. Picking up traces of the nearby mice, it poked its head into the burrow

under the cactus pads. The snake grabbed the first mouse and pinned it against the ground and ate it,

as the second mouse escaped out another opening to its burrow.

One pygmy mouse was not much of a meal for a full-grown coachwhip, and so it continued its search. Five

feet of sandy light brown scales slipped around clumps of grass and rocks, as its reddish brown head

looked this way and that. The coachwhip spotted the whiptail lizard, and the chase was on. Both reptiles

were agile and quick, and the whiptail could dart ahead and suddenly stop, becoming nearly invisible

in the tangle of grass. Its dark body had light yellow-green stripes which blended in with the grasses and

made it harder to make out the outline of its body. The slightest movement would trigger another dash

by the lizard, running in a blur of speed for another

eight or ten feet. But ultimately, it could not outrun the coachwhip, and the snake got another meal.

The body of the lizard had been fed by many insects, and most of the insects were plant-eaters. The

energy of all those plants, passing through the insects and then the lizard, was used by the snake to

grow and to chase down more food.

But that was not the end of the story. A few weeks

later, the coachwhip was once again slipping through the grasses and poking its head into burrows or

under rocks, looking for food. Thirty yards away, perched on the high branches of a live oak tree, a

red-tailed hawk looked out across the field. The hawk’s keen vision spotted movement. A long snake

was moving among the grasses and rocks. The bird took to the air, silently swooping toward the snake.

At that moment, the coachwhip pulled its head back from where it had been checking an old mouse

burrow, and caught sight of the hawk. It made a

The Web of Food, continued

Western coachwhip (photo by Mark Pyle)

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frantic dash toward the edge of the woods, and as the hawk got close, the snake turned hard to the left

without slowing down. The hawk used its powerful wings to pivot in mid air and drop on to the snake.

Strong talons and a sharp beak ended the snake’s life, and the hawk almost immediately rose into the

air and carried the coachwhip’s body up to a safe perch for a leisurely meal.

The food had started in the leaves of plants, and then was used by insects or mice. It passed from these

animals to lizards and snakes, and finally to a hawk. Anything that harmed the plants could, in turn, affect

a great many other animals, even the ones that do not eat plants. In one way or another, plants and

animals are all linked in this way. Grasses and herbs feed cotton rats that are in turn eaten by that

bullsnake that we mentioned earlier. A coyote might also eat the cotton rats (and perhaps the bullsnake).

When biologists talk about how energy is passed from the plant up through the insect, to the lizard, to

the snake, and to the hawk, they describe it as a “food chain.” Each link in the chain is a plant or

animal. The grass is one link, and the insect is another. The lizard is a link further up the chain,

followed by the snake and finally the hawk.

Any prairie or forest or pond has many of these links

at each level, and so biologists talk about a “food web” of plants and animals that are all connected

to each other. The plants do not just support insects, they are food for rats and mice, rabbits,

deer, and other animals. Some animals take food at different levels - for example, box turtles may

eat green plants, mushrooms, fruit, insects, and may feed off the bodies of dead animals.

Sometimes it’s sad to think about how our favorite kind of animal is killed in the wild. Snake-lovers

may not like it that hawks eat snakes. Many bird-lovers are unhappy that some snakes such as

Texas rat snakes eat birds. It may be helpful to remember that this is part of the big picture in

which everything participates in a food web that supports all life.

Crosstimbers Connection - connecting people with nature in north Texas

We take people out into the woods and prairies, looking for reptiles, amphibians, and other wildlife, learning and having fun. And we do it without charging anything (but we gladly accept contributions to keep us going). We are a nonprofit organization - please visit us on the web at: http://crosstimbersconnection.org.

Michael Smith, President - michael@crosstimbersconnection.org Rob Denkhaus, Board MemberMark Pyle, Vice President - markpyle@crosstimbersconnection.org Kaydee Doss, DocentDebbie Dorman, Secretary/Treasurer - ddorman@crosstimbersconnection.org

P.O. Box 151882 h Arlington, Texas 76015

The Web of Food, continued

Ornate box turtle, eating a grape (photo by Michael Smith)