Sunday, December 20, 2009

Baby Praying Mantises

Over the summer we found several big green Praying Mantises around the Earth Discovery Center. We kept one for several days in a container to show students and visitors, and to our delight it laid a brown, styrofoam-like egg case (also known as an "ootheca" - pronounced "oo-oo-thee-ka") on the lid. We planned to put the egg case outside, but instead it got pushed to the back of the reception desk and forgotten about. One day at the end of November we were sitting at the desk and noticed a tiny yellow creature scampering across the phone - the egg case had hatched early due to the warm temperatures! We spent the rest of the afternoon rounding up the 50 or so baby mantises that had scattered all over the desk, floor, and walls.

We kept them all together in a large screened cage for their first few weeks where there was a pretty high attrition rate - so far we have six survivors. This is probably similar to their survival rate out in the wild; most of the hatchlings would fall prey to larger insects.

Here are the six survivors, now living in vials with a foam plug on the top. We put them in the smaller containers so we could keep a closer eye on whether or not they were getting enough food. The cottonballs at the bottom are for moisture, and the smaller black dots in the containers are fruit flies for the baby mantises to eat.
Here's a close up of one of the little doobers - even at this size they have all the personality of the larger mantises. They tilt their heads and wash their legs and antennae, almost like cats.

This one is munching on a fruit fly. A mantis eats by grabbing the prey with its folded pair of front legs and then digging right in and munching on the fly once it has a good grip. As the mantises get bigger, we will switch them to larger insects like crickets.

As the mantises grow, they crawl out of their old skins, leaving an empty "molt" behind. It's amazing how you can see every detail on the empty skin, even the antennae, and the spikes on the front pair of legs. The mantis hatchlings with molt several times until they reach their adult and final molt, at which point they will have fully developed wings and will be able to fly. This process, where the young insects closely resemble the adults, is known as incomplete metamorphosis. Insects such as butterflies, beetles, and flies, which have a larval forms known as caterpillars, grubs, and maggots and form a pupa before the adult stage, go through complete metamorphosis.

Contrary to popular belief, praying mantises in our area are not endangered, and you won't go to jail if you kill one although we'd prefer that you didn't. We have three species of praying mantis in our area: the native Carolina Mantid (Stagmomantis carolina) and two introduced species, the European Praying Mantis (Mantis religiosa) and the Chinese Mantis (Tenodera aridifolia sinensis).

Our babies are of the Chinese Mantis variety - they will eventually reach between 3-5 inches in length. The adults are often brown with green stripes down the edges of the wings. Chinese Mantises were introduced into North America in the late 1800's as a source of pest control - these are usually the species shipped if you order mantis egg cases in the mail, although the release of non-native species is usually frowned upon in most areas.

The native Carolina Mantis is much smaller than the Chinese Mantis - usually around 2 inches, and is often a dusty brown in color. The European Mantis is slightly larger and often pale green in color.

Sunday, November 29, 2009

White Squirrel

All summer we have been getting reports of a white squirrel in the park, living somewhere between the Marina and the Earth Discovery Center, but never managed to actually see it. Finally a park visitor, Richard Gentry, managed to snap a photo and kindly offered to share it:The patches of normally colored fur on the belly and dark eyes indicate that this squirrel is probably leucistic rather than albino. Albino animals have reddish eyes, while leucistic animals usually have normally pigmented eyes. This squirrel seems to be surviving well so far, but abnormally colored wild animals are often easier targets for predators due to their lack of camouflage. He or she also appears to be a fox squirrel, the common species found in the park.

The mutations that cause albinism, leucism, and other similar conditions can occur in humans, birds, fish, reptiles, insects...pretty much any creature that possesses color pigments. Many of our domestic animals, such as rabbits, chickens, and laboratory rats and mice, have been deliberately bred to produce white animals.

Several years ago I raised a litter of orphaned opossums with one leucistic baby, who stayed with me as an educational opossum:

For some animals, like polar bears, snowy owls, and mountain goats, having white fur or feathers is a survival advantage, not a liability, allowing them to adapt and survive in cold and snowy climates. A few, such as the Arctic fox and snowshoe hare, can even shed their fur and change from brown to white as the seasons change!

Check out this website if you'd like to see more photos of these fascinating "Ghosts of Nature"

Sunday, September 6, 2009

Late Summer Wildflowers

We usually think of spring as the time for wildflowers, but a surprising number of flowers bloom throughout the summer. Some of my favorites appear towards the end of summer - I know that when the purple ironweed blooms, fall is not far away!

Queen Anne's Lace, Daucus carota, also known as wild carrot, is a familiar sight along roadsides and open fields. It was introduced from Europe and is considered an invasive weed in many areas, as it can outcompete native plants; however, the leaves do provide food for the caterpillars of the Black Swallowtail Butterfly. The large, carrot-like taproot is edible. Not surprising when you consider that the "wild carrot" is actually the ancestor of our modern cultivated carrots. Use extreme caution if you decide to take a nibble - Queen Anne's Lace closely resembles the deadly poisonous Water Hemlock! Both are members of the parsley family, Apiaceae, which also includes Fennel, Caraway, Anise-seed, Rattlesnake Master (an unusual prairie plant), and Celery.

The flowers of Queen Anne's Lace are compound --composed of many tiny flowers clustered together. They often have one or more dark purple-red flowerlets at the very center, drops of Queen Anne's blood where she pricked her finger while making lace, at least according to legend.

Ironweed, Vernonia altissima, one of my favorite "weeds" of late summer. They usually begin blooming in August in meadows and along roadsides, and their tall vibrant purple blooms are a favorite of bees and butterflies. Ironweed is a member of the aster family, Asteraceae.

Wild Forget-Me-Not, Myosotis sylvatica, is another exotic species, introduced from Europe and Asia. It prefers rich, waterside soils, and has been blooming all summer along the marshy inlet at the base of the amphitheater. Forget-Me-Nots are often used as a symbol of enduring love. In a rather sad legend about the origin of the name, a knight fell into a river while walking with his sweetheart, and tossed her this flower that he pulled from the river's edge, shouting "forget me not," before the weight of his armor pulled him under.

Virginia Spiderwort, Tradescantia virginiana, is a native perennial that blooms mid-spring through summer. It is a member of the Dayflower family - individual flowers often close up by afternoon on sunny days, and each flower only lasts a day or two. The camera didn't capture the color well here - flowers are actually a deeper blue-purple.
A close up of the flower reveals a possible source for the name "Spiderwort" - each anther is surrounded by several tiny filaments that might resemble a spider's web.
This is another member of the Spiderwort or Dayflower family that can be found growing in the park, the non-native Common Dayflower, Commelina communis. This one was found along the trail to the pond by the EDC, and with the two big petals reminded us of a little Mickey Mouse.
Virginia Knotweed, Polygonum virginianum, is common throughout the woods of Eagle Creek. When the seeds are ripe, they will explode away from the stem at the slightest touch, giving the plant its other common name of "Jumpseed."
By far the most noticeable late summer wildflower at Eagle Creek is White Snakeroot, Ageratina altissima. The clusters of white flowers create dense stands through much of the forest understory of the park. White Snakeroot contains the toxin tremetol and is poisonous when eaten, which probably explains its success in areas with high deer populations.
When European pioneers began settling the Midwest in the early 1800's, many of them became ill and even died from the mysterious "milk sickness." One of the most notable victims was the mother of Abraham Lincoln, Nancy Hanks Lincoln. It was not until the 1900's that the cause of milk sickness was officially determined: tremetol poisoning, from cattle that had grazed on white snakeroot plants (Although she never received official recognition, Dr. Anna Bixby probably discovered the cause several years earlier: Normally, cattle avoid the bitter leaves, but if they were being kept in woodland areas with few other sources of forage, they would eat it if they had no other choice.

Sunday, August 2, 2009

Indian Pipes

Down at the end of the Pin Oak Trail I was excited to discover a group of strange pale plants that have emerged from the ground in the last few weeks. They look like they might be mushrooms, but these are actually flowering plants known as Indian Pipes, Monotropa uniflora. Indian Pipes are parasitic on a fungus that is in a mutualistic relationship with a tree. Since they get all of their energy from the fungus (who gets it from the tree) Indian Pipes do not need green chlorophyll to make sugar from sunlight, hence their pale white coloration. If you tilt the flower up slightly, you can see the yellow pollen, proving that these are indeed flowers, and not mushrooms.
For more detailed information on Indian Pipes and their weird and wonderful lifestyle, try these links:

Sunday, April 19, 2009

The Mystery Tree...Revealed!

Remember the tree growing by the pond that had little pom pom flowers growing all along the stems in March? Now that it is mid-April, the flowers have developed into ruffly clusters of light green seeds, and the mystery tree has been identified as the Red or Slippery Elm, Ulmus rubra. The name "Red Elm" comes from the reddish brown color of the heartwood, and the name "Slippery Elm" comes from the slippery, mucus-like substance that can be ground from the inner bark. This mucilage can be made into a tea, or gruel for food, and is also said to be good for sore throats and irritable bowel syndrome. The fibrous part of the inner bark makes good twine or rope, and the wood is very shock resistant due to the interlocking grain pattern - good for making wagon wheels.
The Red Elm is less susceptible to the Dutch Elm Disease than its cousin, the American Elm (Ulmus americana), which has drastically declined in numbers in North America due to this introduced disease.
The seed of the Red Elm is called a samara - a fruit with flattened, papery, wing-like extensions. The "helicopter" seeds of maples and ash trees are also known as samaras.
This particular Red Elm tree has produced thousands and thousands of seeds this spring, while the Red Elms planted in my yard at home barely have any seeds. Like many trees, the Red Elm may not produce a heavy seed crop every year. Seed production takes a great deal of energy, and by "flooding the market" in a particular year, the tree prevents seed predator populations from building up to high enough levels to take advantage of the heavy seed crops. Even so, only a few of the seeds will ever survive to become mature trees.
The leaves of the Red Elm have a wonderful rough, sandpapery texture - we'll have to remember to check them out in May, after the spring "leaf out."
One mystery solved! But there's always another mystery, never fear: just across the trail another tree is flowering, and I...have absolutely no idea what it could be! Stay tuned....


All around the EDC right now you can see the Downy Serviceberry blooming (Amelanchier arborea). These small, slow-growing trees are native to Indiana and were planted in front of the building and in the backyard habitat to provide food and shelter for wildlife. Some varieties of Serviceberry grow as a shrub, rather than a tree. In some parts of the country, Serviceberry is also known as Shadbush, Shadblow, Juneberry, Sarvisberry, Sugarplum, and Saskatoon.
The flowers of the Serviceberry are short-lived, only a week or so, so enjoy them while you can! After the flowers are done, small red-purple fruits form - they look and taste somewhat like blueberries, and are a tasty snack for birds. Sometimes people use them to make jams and jellies as well, if they can manage to beat the birds to them! Many species of caterpillars feed on Serviceberry leaves, providing food for baby birds and insect-eaters, and making it a great native tree to plant for wildlife value. The timing of the appearance of Serviceberry flowers coincides with the "shad run," hence the name "Shadbush." (Shad are a type of fish that swim to their spawning grounds in the spring). The name "Serviceberry" is also related to the timing of the flowers: when pioneers saw the Serviceberry blooming, they knew that the ground had thawed enough to bury anyone who had died over the winter, and the beautiful flowers could also be used as decoration for the funeral service. The Native Americans used the straighter branches of the Serviceberry to make arrow shafts, and used the berries in combination with fat and dried meats to make pemmican. Serviceberry is a member of the rose family, along with blackberries, raspberries, apple trees, hawthorn, pears, and strawberries - you can see the resemblance in the shape of the flowers.

Wednesday, April 1, 2009

Fox Squirrels

The most commonly seen squirrel in Eagle Creek Park is the large, reddish-colored Fox Squirrel (Sciurus niger). Gray squirrels are native to Indiana as well, but there are no populations living in Eagle Creek, although they can be found on the campus of Butler University. The smaller Red Squirrels (also known as Piney Squirrels or Chickarees), barely larger than chipmunks, are present in low numbers in the park, and it is possible we have nocturnal Flying Squirrels as well, although their presence has not been officially confirmed.
Fox Squirrels will nest in hollow trees (or sometimes attics), but they also build nests of dead leaves and twigs high in the treetops. These leafy nests are known as dreys, and winter and early spring before the trees leaf out is the best time to see them. (Nests of large birds can be similar in size, but usually don't contain dead leaves.) Summer dreys may be small and loosely constructed, but winter dreys and dreys built by a mother squirrel for raising babies are sturdy, intricately woven, and lined with soft, insulating material. Fox Squirrels in Indiana can have at least two litters of babies per year: one in early spring, and a second in mid to late summer. The first litter is sometimes born as early as February, although the mother squirrels take a gamble with the chance of severe spring weather. Newborn squirrels are pink and hairless, but despite their lack of fluffy squirrel tail, they are still identifiable by their long front toenails.
A litter of baby fox squirrels was found in a gutter of a house a few days ago - the mother apparently nested in the gutter and the babies were washed out by heavy rains. The babies already have fur and have their eyes open, so they were probably born some time in February. Before I sent them to a wildlife rehabilitator, I got a video clip of the babies trying out some solid food for the first time. As you can see, they're still a little wobbly! The babies will be released back into the wild as soon as they are old enough.

Saturday, March 28, 2009

Spring Peepers

First frog program of the year last night; I was afraid it was going to be too chilly for much frog activity, but we were pleasantly surprised to find the Reflecting Pond absolutely rockin' with Spring Peepers (Pseudacris crucifer) in full chorus. These tiny little frogs are no bigger than your thumb, and can be identified by the vaguely cross-like marking on their backs, which is where the scientific name "crucifer" comes from. They may be tiny, but these little frogs pack some mighty vocal power. A few minutes spent in the middle of an army of chorus frogs and your ears actually ring. ("Army" is the term for a group of frogs, like "flock" is to birds). Only the males call, trying to attract a female. Calling is the most energy expensive activity a frog can do, so the females know that males able to call long and loud are likely to be healthy and good potential fathers for their eggs, genetically speaking, anyway. Once the eggs are laid, both male and female Spring Peepers head back to the forest, and the tadpoles grow up with no parental care needed.
Here's a video clip of a male Spring Peeper calling, with another nearby, probably a female. The male really puts his whole body into the effort of calling - hopefully the female peeper was impressed!

And another short clip of a peeper calling - this one looked like he waved at me!

Peepers were the only frog we heard calling, but I did spot one very sleepy Bullfrog (Rana catesbeiana) poking her head up. Spring Peepers spend the winter in the forest, burrowed underground. They actually have an anti-freeze-like substance in their bodies that prevents them from suffering damage from sub-freezing temperatures. Bullfrogs, on the other hand, spend the winter under the ice of the pond, hibernating in the leaves and muck at the bottom. Because of the cold temperatures their energy needs are very low, and they can take in enough oxygen through their skin to sustain them.

I could tell this Bullfrog was a girl because her tympanum, or ear, the little circle just beneath her eye, is smaller than the eye. On a male Bullfrog the tympanum is larger than the eye. This doesn't work for Spring Peepers, but you can still tell the males apart by the yellowish or dark brown deflated vocal sac on their throats, while females have white throats.

Thursday, March 26, 2009

Hemlock and Spruce and Pine, oh my!

There are several coniferous tree species found in Eagle Creek Park; for instance, the long magestic row of tall Norway Spruce (Picea abies) trees with their graceful upward arching branches along the main road by the Ornithology Center. They were originally planted by the Lilly family, and there are several around the EDC as well. As the name suggests, Norway Spruce is native to Europe. There is a White Spruce, Picea glauca, which is native to Indiana, but I've not found any growing in the park.Spruce needles are very stiff, and quite sharp. Folks who celebrate Christmas with a live spruce tree usually have a few uncomfortable prickly moments setting them up!The cones of the Norway Spruce have densely packed scales, and are 6+ inches long (cones of White Spruce are much smaller - less than 3 inches). Squirrels like to strip them of their scales and eat the seeds, leaving the central stem of the cone behind.
If Norway Spruce has the biggest cones, the Eastern Hemlock (Tsuga canadensis) has the tiniest - these little doobers are only about an inch long.
Eastern Hemlock has flat, rounded needles, soft and flexible, rather than stiff and sharp, with two whitish lines on the underside. This is not the same hemlock that killed Socrates (the poison he drank was made from an herbaceous plant that looks a bit like parsley - Poison Hemlock, Conium maculatum) so don't worry about touching and handling Eastern Hemlock, it won't bite! In fact, pioneers often made tea from the needles, which, like most conifer needles, are high in vitamin C. Deer also find the Hemlock needles tasty; the trees in the park are all browsed as high as a white-tailed deer can reach.
Eastern Hemlock prefers cool and humid growing conditions, and unlike most other conifers it can grow in the shade. Most of the trees in the park were probably planted, but they grow naturally in ravines in southern Indiana. These cool, humid microclimates became refuges for hemlock trees when the glaciers retreated long ago, and Indiana became too warm and dry for them to survive in more upland forest.
Next we have the cones of the Eastern White Pine (Pinus strobus) - similar in size to Norway Spruce, but the scales are much less densely packed, and they are often adorned with white bits of sap on the ends. White Pine is native to Indiana, but the original range was only in a few small pockets - the trees in the park were probably planted. Check out the "Native Trees of Indiana Riverwalk" for some excellent range maps of Indiana trees:
White Pine holds the record of being the tallest tree in eastern North America; pre-colonial trees were reported to reach over 200 ft tall, and the current record holder is just over 180 ft. The tall, sturdy trunks of the White Pine were in great demand during colonial times to be turned into masts for the ships of the British Royal Navy.
There is a large White Pine growing near the deck at the Ornithology Center, and one at the edge of the Grasshopper Field by the EDC.
Needles of the White Pine are long and slender, and grow in clusters of five. Quite conveniently, the word "white" has five letters, making this fact a little easier to remember. The needles look sharp, but they are actually quite soft and flexible.
The other common pine tree in the park is the Virginia Pine (Pinus virginiana). Its needles grow in clusters of two, and the needles are slightly twisted or spiraled. There are several stands of Virginia Pine planted in the park - you can find them growing along both the Pin Oak Loop and the Cabin Loop Trail by the EDC. Virginia Pine is native to Indiana, but only occurred naturally in the south, along the Ohio River.
Most of the Virginia Pine trees in the park look rather worse for wear. It is hard to even tell they are pines in most cases, unless you look to the very top and see the needles. Virginia Pine is shade intolerant, and has a very short lifespan - only 60 to 90 years - and that is about how long ago they were planted. Norway Spruce can live a little longer, 100-200 years, and White Pine and Hemlock can reach ages of 300 to 400+.
The cones of Virginia Pine are medium in length, around 3 or 4 inches, and have a sharp thorny spur on the tip of each scale.

Ohio Buckeye

The first tree to leaf out in the park is the Ohio Buckeye, Aesculus glabra. Most of them are quite small - there are clusters of young trees at the end of the driveway coming out of the Ornithology Center, another patch just before the sharp curve at Fisherman's Cove, and near the end of the Cabin Loop trail by the EDC. I only know of one big tree in the park, although there are probably others scattered around.
The European version of the Buckeye is known as the Horse Chestnut, Aesculus hippocastanum, and is sometimes planted as a landscape tree. Despite the name, this is not the chestnut of "roasting on an open fire" fame - the nuts produced by both of these trees are actually toxic to humans, although deer and a few other animals can eat them without harm. Edible chestnuts come from the American Chestnut, Castanea dentata, a member of the beech family, which sadly has disappeared from most of our forests due to an introduced fungal disease.
Although it may look like I'm holding five leaves here, in actuality there is only one compound leaf in the picture, a single leaf composed of five leaflets. Buckeye leaves are also palmate - shaped like a hand with all of the leaflets connecting at the center. Some compound leaves, like those of the walnut, are pinnate - shaped like a fern, with the leaflets along a central stem. The new leaves are dark red, but they'll turn green as they get larger.
Here's a photo of a Buckeye from earlier in the year, which shows how the buds/leaves are arranged in an opposite pattern on the twig, rather than alternate. Opposite leaf and bud arrangement is an important clue when it comes to tree ID, as there are only a few tree groups that have opposite leaves: Maple, Ash, Dogwood, Horse Chestnut, and Buckeye. MAD Horse Bucks is an easy way to remember the opposite-leaved tree groups. I've also seen MAD Cap Horse - the "Cap" stands for the family Caprifoliaceae, which includes shrubs like honeysuckle, viburnum, and elderberry, all opposite-leaved.

Tuesday, March 24, 2009

Wildflowers - the leafy preview!

Over the last week, the forest floor has become a carpet of wildflower leaves, poised to burst into bloom. Here's a preview of coming attractions!

Spring Beauty
Cut-leaf Toothwort
Deer Tongue / Trout Lily
Toad Trillium
Dutchman's Breeches
Mayapple unfurling
Like a patio umbrella


Similar to Bloodroot, Hepatica blooms early and briefly - you have to stay alert to catch it in the spring! On first glance Hepatica can look a little like Bloodroot, but the leaves are very different. These flowers were growing along the staircase up to the cabin. Sometimes the leaves are green, but along the staircase they were dark red - can you spot their three-lobed shapes among the dead tree leaves? The Hepatica was also blooming all along the bank overlooking the little creek in the ravine, at the bottom of the wooden staircase on the Cabin Loop Trail.
Hepatica can be white or lavender in color:
My favorite thing about Hepatica though? It's fuzzy! The stems and new buds are covered with white fuzzy hairs, probably as insulation from the cold temperatures of early spring.