All posts by Upper Highland Lakes Nature Center

Nature’s Most Efficient Predator

If you had to name the most successful hunter in the animal kingdom, which animal would you pick?   the lion?  the shark?   The lion captures its prey only about 25% of the time.   Those gazelles are fast!  Even with their huge mouths and all those teeth, sharks miss over 50% of the time.  Those fish may be small but they can swim quickly and dart behind coral. Continue reading Nature’s Most Efficient Predator

Who, who, whoooo is that?

It’s amazing what you can see in nature if you listen carefully and look all around you.  This lovely creature was spotted protecting her nest in an old tree on the ranch where the nature center is located.  Notice how beautifully her coloring helps to camouflage her against the colors of the old wood.

Mama owl guarding the nest at Reveille Peak Ranch. (Courtesy of Jim Baines)
Mama owl guarding the nest at Reveille Peak Ranch.
(Courtesy of Jim Baines)

This is a great horned owl.   These majestic birds have the widest range of any owl species, ranging from Alaska and Canada to Patagonia in South America.

Great Horned Owl (Courtesy of Paula Richards)
Great Horned Owl
(Courtesy of Paula Richards)

Naming these birds is easy.  The “great” is because they can be up to two feet in height, with wing spans of up to five feet.  The “horned” part is because of their ear tufts that look like horns.  They are also known the tiger of the skies because they are so large and fierce.  This owl is certainly at the top of its food chain!

As with other creatures this time of year, the owls are busy raising their young, nesting in tree holes, rock crevices, or even old squirrel nests.    Owls select their mates through a ritual that includes hooting, bowing, and rubbing beaks.   These youngsters have yet to grow into their final plumage that will help hide them in the woods during the day.

Young horned owls at Reveille Peak Ranch, near the nature center. (Courtesy of Jim Baines)
Young horned owls at Reveille Peak Ranch, near the nature center.
(Courtesy of Jim Baines)

Did you know that these owls are the only animals that actually seek out and feed on skunks?  Can you imagine that?  Fortunately, there are other delicacies for owls to choose from such as other birds, mice, fish, snakes, lizards, rabbits and other small mammals they find out and about at night.

Like the screech and other owls, the great horned owls have amazing eyesight capable of spotting a tasty morsel even in the lowlight of the nigh time forest and meadows.  The owl can turn its head a full 270 degrees without moving the rest of its body to help pinpoint its target.   (Compare this to what us mere humans can do.  Keeping your eyes still, see far can you turn your head to the right or left.)

Parent watching out for young owls. (Courtesy of Jim Baines)
Parent watching out for young owls as night falls.
(Courtesy of Jim Baines)

If you spot a great horned owl tilting its head to the left, to the right, it is probably trying to find the source of a sound, and perhaps a little snack.  Their hearing is far better than humans.  Their ears are placed differently on their heads, with the right one usually higher than the left and at a different angle.  This helps them quickly locate the source of a sound, above or below, left or right, in front or behind, close or far.   (Think about how you hear sounds such as a bird in a tree, or your friends calling you to play.  Do you tilt your head too?)

Go out early some morning or late in the evening and see if you can hear a great horned owl.  You will know who, who, whooo that is!

Help! We’re being invaded!

Author: Minnie Eaton

Chinaberry tree. (Courtesy of Texas Forest Service @ Texas A&M)
Chinaberry tree.
(Courtesy of Texas Forest Service @ Texas A&M)

On our website, in our projects and nature bytes, we usually focus on native plants and species.  These are plants and animals that occur naturally in our ecosystem here in the Texas Hill Country.  They are well adjusted to our soils, weather, and fit in nicely within our self-sustaining ecosystem, our Texas flavoured biodiversity.

asian longhorned beetle
Asian Longhorned Beetle. (Courtesy of Michael Bohne, Invasives.org)

Unfortunately, invaders can sneak into the mix and overwhelm our natives to a point where they cause significant damage to our ecosystem.  They can be introduced into our environment by birds carrying seeds, by strong winds, but most often it is people who bring these invaders to our shores.   They can cause damage by (example species):

  • Introducing diseases or new predators our native species are not equipped to handle (feral pigs, ash borer and longhorned beetle)
  • Competing with natives for scarce resources such as water and food, or even soil in which to put down roots, often providing no or little nutritional value to our native creatures (chinaberry tree, star-thistle and grass carp)
  • Causing changes to native habitat (giant reed and zebra mussel)
  • Causing damage through loss of crops and trees, damage to electrical systems and other economic impact (Asian long horned beetles, gypsy moths, and crazy ants)
Gypsy moth. (Courtesy of Invasives.org)
Gypsy moth.
(Courtesy of Invasives.org)

To learn more and to find out what each of us can do to help, we met with Justin Bush, the Plant Conservation Invasive Species Coordinator from the Lady Bird Johnson Wildflower Center.    The official definition of an invasive species is one that is a non-native introduced into an ecosystem that causes economic or environmental harm or harm to human health.

  • Invasive species are a form of biological pollution, that change and decrease biodiversity by threatening the survival of native plants and animals.
  • They may be introduced accidentally or on purpose, from produce, nursery stock, ships, recreational vehicles, and packing materials, pets/aquariums, and agriculture, to name a few.
  • They are spread by the elements, wildlife, flight, or by humans using ornamental plantings, erosion control, mowing, vehicles, firewood, and boats.
  • Invasive species can even damage the environment by hybridizing with native species to the point where native species are threatened with extinction.
Bastard Cabbage. (Courtesy of Mark Simmons, Lady Bird Johnson Wildflower Center)
Bastard Cabbage.
(Courtesy of Mark Simmons, Lady Bird Johnson Wildflower Center)

Of all the invaders, Mr. Bush named  “The Dirty Dozen”, the nine most unwanted plants and three most unwanted pests.

  1. Glossy privet
  2. Chinese tallow tree
  3. Johnson grass
  4. Tree of heaven
  5. Chinaberry tree
  6. Giant reed
  7. Malta star-thistle
  8. Common water hyacinth
  9. Bastard cabbage
  10. Cactus moth
  11. Emerald ash borer
  12. Asian longhorned beetle

With the help of the Wildflower Center, Texas Parks and Wildlife, and  other similar organizations across Texas and in cooperation with other states, they are trying to educate the public to control and even stop these invasions.  A first stop for more information about these invaders, their economic and environmental impact, and what is being done is the website for Texas Invasives.

Giant Reed. (Courtesy of James H. Miller, USDA Forest Service)
Giant Reed.
(Courtesy of James H. Miller, USDA Forest Service)

Everyone can do their part, even if it’s just cleaning your sneakers or hiking boots to make sure you’re not carrying invasive seeds home from your hike or camping trip, washing down your boat or jet ski after a fun trip in a lake or river, and double checking those nursery plants before you plant them — do they really belong in Texas?

Zebra mussels. (Courtesy of Texas Parks and Wildlife)
Zebra mussels.
(Courtesy of Texas Parks and Wildlife)

To really roll up your sleeves and get involved, the Citizen Scientists Program provides training for those who want to actively participate.  You will learn how to detect and report invasive species, and how to collect and submit data about the what, when, where and how many to the official tracking sites.

A special thanks to Justin Bush for a most interesting conversation and a call to action for all of us!

 

Scavenger Hunt for Young Naturalists

Eastern bluebird nesting in a tree.  (Courtesy of Jim Baines)
Eastern bluebird nesting in a tree.
(Courtesy of Jim Baines)

The nature center recently had the pleasure of hosting fifth graders from Highland Lakes and second graders from Lago Vista, along with parents and teachers.  Led by nature center members, they  hiked along the lake and trails, hunting for beaver signs, lovely song birds (such as the bluebird above), interesting water birds, unique rock formations, wildflowers and other cool Texas plants.

Lichen vs Moss vs Rock (Courtesy of Paula Richards)
Lichen vs Moss vs Rock, with naturalist Mike Parker.
(Courtesy of Paula Richards)

For the day, they became the  naturalists, complete with filling in their own field guides, exploring the wilds of the Texas hill country.

Young naturalists working on their field guides. (Courtesy of Paula Richards)
Young naturalists working on their field guides.
(Courtesy of Paula Richards)

They found different types of cactus, and even looked at bugs that spend their entire lives on cactus and produce an amazing red dye.  They discovered a tree that makes Texas BBQ so delicious, the mesquite tree, and a plant whose berries make wonderful jelly, and whose leaves were used by Indians to make a tea for upset tummies.

A young scientist hard at work! (Courtesy of Paula Richards)
A young scientist hard at work!
(Courtesy of Paula Richards)

They even found an usual resident for this time of the year:  a pair of Canadian geese nesting on an island near the lake shore.

canadian+goose+on+nest
Canadian goose on nest.
(Courtesy of Jim Baines)

These young naturalists also spent time at different nature stations.  They learned about beavers and their habitat, including a model of a beaver den, which they could explore.

Good thing this is a model, otherwise he'd be very wet! (Courtesy of Phil Wyde)
Good thing this is a model, otherwise he’d be very wet!
(Courtesy of Phil Wyde)

Did you know that a beaver’s teeth continue to grow their entire life and that the black willow is their favourite tree?  Did you know that the entrance to their home is under water but the living quarters is nice and dry? Want more?  (link)

Learning about how a beaver fur protects them in and out of the water. (Courtesy of Paula Richards)
Learning about how a beaver fur protects them in and out of the water, with naturalist Sharon Drake.
(Courtesy of Paula Richards)

At another station, they learned about how animals become masters of camouflage to survive.  Some blend in with their environment such as rabbits whose fur blends in with the shadows in the forest, or walking sticks shaped like the branches and twigs they climb.  Swallowtail caterpillars actually mimic a common green snake to discourage those who may think they’re a tasty morsel.  For more, try this link.

Learning about the importance of camouflage. (Courtesy of Paula Richards)
Learning about the importance of camouflage, with naturalist Phil Wyde.
(Courtesy of Paula Richards)

At the third station, bees were the sweet topic.  They discussed the importance of bees in the environment, how they pollinate plants, make honey, and build their hives. Sadly, honey bees colonies are endangered, and are less than half of what they were in the 1940s.  Did you know that more that 85% of plant species require pollinators, and that one of every three bites of food we eat comes from plants that depend on honey bees and other pollinators?  Without bees, how would we feed our families?  While scientists are still trying to figure it all out, there are some simple things each of us can do (link).

Right on!  The importance of the honey bee. (Courtesy of Paula Richards)
Right on! The importance of the honey bee, with naturalist Billy Hutson.
(Courtesy of Paula Richards)

Miss Arlene, our friend from the wildlife rehabilitation center, showed the children baby opossums whose mother had been hit by a car.  They were still too young to be released.

"Opossum
Baby opossum sipping milk.
(Courtesy of Phil Wyde)

She also brought young bunnies who were ready to be released back in to the wild, which she did.   She taught the children how a mother rabbit builds its nest, and brought a nest roof made of grasses.  She showed them how to use flour and a sieve to see the tracks of creatures who visit their yard.

Baby rabbit heading home to the wild. (Courtesy of Phil Wyde)
Baby rabbit heading home to the wild.
(Courtesy of Phil Wyde)

As always, the children were excited to learn about these wild creatures and how to be kind and careful when around them.

I know! I know! (Courtesy of Phil Wyde)
I know! I know!
(Courtesy of Phil Wyde)

By the end of the day, the children, parents and teachers were tired but full of all they had seen and learned.  One student commented that he thought it was going to be boring, but he’s really glad he came and wanted to know when he could come again!  All in all, a very good day!

Brownies have an exciting day!

Brownies braved a chilly April morning to visit the nature center to learn about entomology (the study of insects) and basic hiking.  According to Phil Wyde, the nature center’s chief bug-guy, insects account for more than two-thirds of all known organisms and have been present on the earth in some shape or form for more than 400 million years.

Look what they found under this old log! (Courtesy of Paula Richards)
Look what they found under this old log!
(Courtesy of Paula Richards)

The Brownies were not the least bit squeamish, finding bugs under logs and rocks, in the grasses along the trails, catching them in nets, and studying them thru magnifying glasses.

A magnifying glass comes in handy when studying bugs. (Courtesy of Paula Richards)
A magnifying glass comes in handy when studying bugs.
(Courtesy of Paula Richards)

With the help of the nature center’s Hollis Zender, the girls created their own bugs, a walking stick (see photo below), and learned about how bugs have specialized mouth parts to allow them to pierce, chew, bite, suck, or sponge up their food.

Studying the wings of a butterfly. (Courtesy of Paula Richards)
Studying the wings of a butterfly.
(Courtesy of Paula Richards)

For the hiking portion of the day, the girls learned how to be safe while out on the trails.  This included what to pack in your backpack:  plenty of water, first aid supplies, gorp to munch on, a trail map, flashlight, etc.  and to make sure someone knows when and where they are going.

Making your own first aid kit. (Courtesy of Paula Richards)
Making your own first aid kit.
(Courtesy of Paula Richards)

While hiking, the girls discovered old bones and talked with Billy Hutson, their guide, about how to determine what kind of animal it might have been, from turtles to armadillos, from deer to cows, from the hollow bones of birds to fish.  All were nicely scrubbed clean thanks to our friendly bugs.

Finding a turtle shell. (Courtesy of Paula Richards)
Finding a turtle shell.
(Courtesy of Paula Richards)

To top off the day, Arlene Pearce, our friend from the bird rehabilitation center,  showed baby opossums whose mother had been killed by a car, and a screech owl with a back injury that she had nursed back to health.  Unlike humans, the large eyes of owls have no muscles attached to move them.  Instead, they have an extra vertebrae in their neck so they can move their head to find their prey.  While the baby opossums were too young to release, Arlene let the Brownies help with the release of the screech owl.

Best screech owl
Screech owl ready to find new home.
(Courtesy of Paula Richards)

 

Getting a closer look. (Courtesy of Paula Richards)
Getting a closer look.
(Courtesy of Paula Richards)

 

There she goes! (Courtesy of Paula Richards)
There she goes! The moms are enjoying it too!
(Courtesy of Paula Richards)

At the end of the day, everyone was exhausted and all the girls had earned their badges.  Congratulations ladies!

“Field of Dreams” for a Geologist!

CTC geology students listen as Charles Beierle from the Nature Center explains the key features of the geology amphitheater. (Courtesy of Jo Ellen Cashion)
Geology students listen as Charles Beierle from the Nature Center explains the key features of the geology amphitheater.
(Courtesy of Jo Ellen Cashion)

Over the course of a couple of weekends, 80 college students and professors from Austin Community College and Central Texas College recently explored the geology amphitheater, located just down the hill from the nature center.   The amphitheater was created in the 2007 floods caused by the 20 inches of rain that fell over four short, wet hours.  When the waters subsided, this treasure trove of geology was revealed.   The nature center geologist described it as “reading postcards from the past.”  In this case, the postcards dated from about 1.2 billion years ago!!

Geology Amphitheater Wall.   (Courtesy of Paula Richards)
Geology Amphitheater Wall.
(Courtesy of Paula Richards)

One of the students said it was like walking thru his text book, all of the geological rock classifications are present and within easy reach.   From the core elements of nature’s mountain building process in igneous rocks, to the layering from the sedimentary period of development and the fusing and formulation of metamorphic rocks, it’s all there.   Also clear is the destructive force of nature, with thousands of gallons of water a minute rushing thru the creek and eroding tons of materials, uncovering rocks that have not seen the light of day in tens of thousands of years.

Xenolith  (Courtesy of Paula Richards
Xenolith
(Courtesy of Paula Richards

In the photo above, the twisting, layering, faulting and uplifting visible in the rock face tells the story of the geological heart of Texas.  Notice how the rock looks folded and is turned on edge so we can clearly see the layering.  Also note the white stripe within the darker rock above, called a xenolith.  It is amazing to think of the power required to force the one into the fault line of the other, and that the white material, in this case granite and quartz, is actually 300M years younger than the material surrounding it.  Examining the size of the schist crystals, we can tell how quickly the material cooled, and we’re talking in terms of hundreds of thousands of years to cool and form these crystals!

As these student can attest, if you want to make your favorite geologist happy (especially your professor) just bring them out to the nature center and let them explore to their heart’s content.  It was a wonderful way to make science real.

Nature Center welcomes a new resident

prerelease owl
Ready to take flight!
(Courtesy of Paula Richards)

A new member of the nature center family arrived via cardboard box and was released at dusk to fly off into the trees and establish his new home.  The screech owl is one of the smallest owls.  Its call can sound like the whinny of a horse or a deep trill.   Like other owls, they eat primarily birds and small mammals.   They live mostly in wooded areas and nest in tree cavities.    This screech owl has only one working eye.  It had been hit by a car and suffered damage to both his eye and ear on the left side of his head.

Arlene and our new owl. (Courtesy of Billy Huston)
Arlene and our new owl.
(Courtesy of Billy Hutson)

This particular screech owl came to us courtesy of Arlene Pearce and her rehabilitation work with wild birds.  Some have been hit by cars, found abandoned in their nests, attacked by family pets or even electrocuted from outdated electrical wiring.  Most come to the center thanks to concerned citizens such as yourselves.  Since 1999, she has mended countless wings, hand-fed fledglings and even raises mealworms to feed her patients.  Working closely with local Texas Parks and Wildlife rangers, veterinarians and local ranchers, she treats and releases over 100 birds each year.   In 2013, she rehabilitated and released 20 screech owls like ours.

Owl fledglings. (Courtesy of Arlene and Richard Pearce)
Owl fledglings.
(Courtesy of Arlene and Richard Pearce)

Stay tuned as we will be releasing another screech owl when the girl scouts visit next month.  We are looking forward to making Arlene and Richard’s rehabilitation work an on-going part of the nature center activities.

The martins are coming! The martins are coming!

Author: Lynn Wolheim.

Purple martins along the Llano River. (Courtesy of Lynn Wolheim)
Purple martins along the Llano River.
(Courtesy of Lynn Wolheim)

Driving thru the hill country, you may have seen collections of white gourds or multi-level bird houses positioned high above the ground on a tall pole, with a pulley system similar to that used to raise and lower a flag.    They are usually positioned out in a field or meadow.  These structures are designed to attract purple martins and give them a safe place to raise the next generation of these beautiful birds.

If you are fortunate enough to have erected one of these purple martin houses, or live nearby someone who has, you are in for a real treat during the next 6 months.  The pair-bonded martins began arriving around Valentine’s Day.  Several have already been spotted soaring, swooping above, landing on, and going in and out of apartment style houses or  colonies of gourds, checking out the neighborhood.

Checking out the neighborhood. (Coutesy of Lynn Wolheim)
Checking out the neighborhood.
(Coutesy of Lynn Wolheim)

Martins, North America’s largest swallow,  rarely nest in the wild, preferring man-made structures in close proximity to water and  people.  Note the metal hooks placed in front of the entrances to the gourds to keep out owls.

The next generation off to a good start. (Courtesy of Lynn Wolheim)
The next generation off to a good start.
(Courtesy of Lynn Wolheim)

As the weeks progress, the martins will find mates, occupy houses, build nests, lay and incubate eggs, have babies, feed them, and watch them fledge.  Notice how the cozy nests are made of leaves, grasses to provide a soft bed for the eggs.

Around the Fourth of July, they will gather together in mass and begin their journey back to South America, only to fly back to the hill country again next February.  We’ll be ready for them at the nature center, and you can be too!

Check out these links for more information and how to prepare your own purple martin housing complex:
Good publications:
  • Purple Martin Book:  The Complete Guide to Attracting and Housing Purple Martins, by D. Stokes, L. Stokes, and J. Brown
  • “The Purple Martin and its Management in Texas.” by James D. Ray, written for Texas Parks and Wildlife

Planning a Nursery for Butterflies

Authors:  Terri Whaley and Minnie Eaton.

Butterflies have long been seen as a symbol of rebirth – their pollination of plants is an essential part of nature’s annual renewal.   The Monarch butterflies are perhaps the most well known.  They are truly a natural wonder, migrating up to three thousand miles from Mexico to Canada and back each year!

Swarm of Monarchs. (Courtesy of Marvin Bloomquist)
Swarm of Monarchs.
(Courtesy of Marvin Bloomquist)

Each species of butterfly has specific needs that we call habitat and must have certain plants in order to survive.  Monarch butterflies lay their eggs only on milkweed plants.  After the eggs hatch, the caterpillar offspring eat the milkweed leaves until growing large enough to form a chrysalis to protect the butterfly as it develops.  After a few weeks, a mature butterfly emerges to dry its wings for several hours before flying away in search of nectar and to continue the migration.

Monarch caterpillar  on a milkweed blossom. (Photo courtesy of Sue Kersey)
Monarch caterpillar on a milkweed blossom.
(Photo courtesy of Sue Kersey)

Unfortunately, according to Monarch Watch (monarchwatch.org), Monarch butterfly populations are declining due to loss of habitat.   Therefore, at the Upper Highland Lakes Nature Center, we are building a Monarch Waystation garden to help the butterflies as they pass through central Texas during both spring and fall migration.  Because loss of habitat means less milkweed is available, our garden will have several species of milkweed to serve as a Monarch “nursery”.   Additionally, we will have many plants with flowers to provide nectar for the adult Monarchs and other species of butterflies, as well as bees, hummingbirds, and other pollinators.

A healthy breakfast for a Monarch. (Courtesy of Terri Whaley)
A healthy breakfast for a Monarch.
(Courtesy of Terri Whaley)

As you visit the Nature Center in the coming months, you will see the garden evolve and learn ideas to take home to create your own habitat for raising Monarchs and other butterflies in your yard.

For example, look for butterflies (usually males) sipping water at mud puddles to get the salts and minerals they need that are not available in flower nectar.  This action is called “puddling” and you can create your own puddler at home by keeping a shallow bowl filled with sand or mud that you keep moist.  It’s a good idea to add a little Epsom salts for minerals and flat stones so the butterflies can sunbathe.  You can do your part to help these lovely creatures, just as we are doing at the nature center.

Signs of spring, finally!

Just when you thought this cold weather would hang around forever, the sun came out and temperatures rose to the 60s and 70s.  It was a hopeful sign that spring is on its way.  We saw other signs on a recent walk along the nature center trails.

We found our first anemone of the season.  It was all by itself but what a welcome sight!

Anemone
February bloom: Anemone
(Courtesy of Paula Richards)

Anemones come in a variety of colors ranging from white to pink to purple, and a variety of petal formations.   (They are not related to the sea anemone which is actually a group of meat-eating animals.  However, the sea anemone is named for the anemone flower.)   The name Anemone comes from the Greek word for wind as it was thought that the flower opened in response to the spring wind.   Containing a mild neurotoxin, anemones were used by some early natives to treat wounds.   Blooming from February to May, look for more of these in the coming months and see how many different colors you can find.

Along the trails, in the gravel, in the low grasses, we also spotted a number of these small rosette clusters of leaves that reminded us that soon we would see Texas bluebonnets.  In spite of the recent dry weather, the fall rains gave these beauties a head start.   Stay tuned for more on bluebonnets as they begin to bloom.

Bluebonnet leaves.
Bluebonnet leaves in February.
(Courtesy of Paula Richards)

The next time you’re out walking, look for signs that a change in seasons is coming.  Are you seeing new birds as they begin their migration north for the summer?  Are you starting to see the buds on the trees start to swell?  Are critters starting to stir from their winter hibernation such as snakes sunning themselves on the rocks?  What other small jewels are in and amongst the rocks and grasses that tell you our Texas wildflowers will be blooming in a month or so?  There is so much to see and learn, just look around… and don’t forget to look up and down.  You don’t want to miss anything!