Spectacular Spiders: The Dark Fishing Spider

Dark fishing spider (Dolomedes tenebrosus)

River Legacy Park is home to hundreds of spider species. One very common spider species is the dark fishing spider (Dolomedes tenebrosus). This spider is primarily found on trees and it is most often seen in the month of May, although it can also be spotted all the way until September. Despite the fact that it is called a “fishing spider,” it does not live near water or fish. It is in fact, the most terrestrial, of the fishing spiders. It is quite big: females can measure anywhere from 15 to 26 millimeters whereas the males tend to be smaller, from 7 to 13 millimeters. The female produces egg sacs that can contain up to 1,000 baby spiders inside!

Spiders serve many purposes in the ecosystem at River Legacy, mainly prey control. It is estimated that all of the world’s spiders consume about 400 to 800 tons of prey each year! Spiders are also a great group of organisms for learning a wide array of concepts: predation, invertebrate biology,  how venom works, the amazing design abilities of the animal kingdom, etc.. Learning about spiders can help in reducing arachnophobia.

During our Spectacular Spiders Summer Class, students will learn all about spiders and why they are cool and interesting. Space is filling up quickly though so visit our website to sign up and learn more information. We hope to see your child there!






Update On Mexican Buckeye Tree!

Mexican Buckeye growing

Last November, through our brand new Saturday Conservation program, we planted a small Mexican buckeye tree (Ungnadia speciosa) provided by the City of Arlington with the help of some awesome volunteers. The tree was already roughly 4 feet tall and it was in a state of dormancy, meaning it had no leaves growing at the time. Fast forward to May and the tree is doing quite well!

Mexican buckeye is a small tree that grows in scattered places throughout central and western Texas, southern New Mexico, and northeastern Mexico. It grows to about 30 feet in height and produces beautiful, bright pink flowers. When pollinated, these flowers produce a capsule-looking fruit with 3 black seeds inside of it. Its seeds are considered poisonous for consumption. It is a great attractor for hummingbirds, butterflies, and other pollinators!


Mexican buckeye seeds

The planting of this tree could not have been possible without the amazing help of a handful of participants for our Saturday Conservation program. This program aims to educate and engage the public in issues regarding conservation and preservation of nature all around us.

Join us for the last Conservation Saturday program for this Spring on May 18th at 11 A.M. The topic will be all about reptile conservation, what the status of reptiles is in our area and worldwide and some ways people can help in reptile conservation. It is a FREE event though space is limited. If you would like to attend, you may give us a call at 817.860.6752 to R.S.V.P. If you would like more information about the program, you may call 817.860.6752 extension 125. We hope to see you all there. Information for Saturday Conservation days for the 2019-2020 year will be posted in the summer. Stay tuned!

Diversity of Plants

Spring time is the perfect time to go out and discover the variety of plant species found in River Legacy Park. Most plants at River Legacy are contained within the flowering plants, as are most plants around the world. These are known as angiosperms. They produce flowers and a fruiting body to protect the seeds once pollination has occurred. Species include the saw greenbrier (Smilax bona-nox), poison ivy (Toxicodendron radicans), osage orange tree (Maclura pomifera), Mexican plum (Prunus mexicana), etc. In addition to the flowering plants, there are 3 other major groups of plants with River Legacy representatives as well.

The mosses constitute a group of plants that like to grow in dense clumps on a typically moist surface. This could be a log on the ground, the bark of a tree, a bench, a boulder, etc.. They are non-vascular, meaning they have no system with which to transport a lot of nutrients and water. They are also very short and produce spores instead of seeds.

Ferns form the other major group of River Legacy plants. In contrast with mosses, ferns are vascular and are bigger. In addition, ferns have compound leaves divided into many leaflets. And, while ferns produce spores like mosses, these are located underneath the leaves of the plant instead of at the tip of the shoots. You might be able to find the bluntlobe cliff fern (Woodsia obtusa) along the trails near Snider Creek at the back of the Science Center parking lot. You have to look closely on the cliff itself to find this plant!

The gymnosperms is another group of plants that produce seeds instead of spores. The difference between them and the angiosperms is that gymnosperms do not produce a fruit to protect their seeds. Normally the seeds are in the form of a cone. One of the gymnosperms that makes River Legacy its home is the eastern juniper or red cedar tree (Juniperus virginiana). Look for a 16 to 60 foot tall tree with light reddish or brown bark with leaves that look like needles instead of a typical leaf shape.

Plants are awesome! We hope you will explore the trails surrounding River Legacy Living Science Center or in River Legacy Park so that you can enjoy them!

3 groups of plants are represented in this picture! Moss can be seen in the background, some ferns can be found at the top left-hand corner and in the middle right section, and a small flowering plant can be seen at the bottom right-hand corner!





Mammals, Reptiles, and Creepy Crawlers, Oh My!

Magnificent Mammals – Dec. 26!

Over the past couple of posts, we have talked about many of the mammals, reptiles, and other vertebrates that live in the woods of River Legacy. Often times, though, not enough attention is paid to the small critters (usually referred to as “creepy crawlies” or “creepy crawlers”) that often inhabit the forest floor. These include insects, arachnids, and other invertebrates.

Throughout history, these animals have traditionally been seen as scary, off-putting, or unpleasant for various reasons. But, in reality, the vast majority of them are just as fascinating as other more charismatic animals (mammals and reptiles), just as important to the healthof the River Legacy forest, and not aggressive. Many of these are decomposers and, thus, they form a key component of the energy flow in the forest. Several of them also prey on other animals that could be detrimental if their numbers got out of control. At the same time, many are important food items for other animals higher up in the food chain. The list of their attributions to the environment is endless. Join us to learn more about these Creepy Crawlers as well as mammals and reptiles during our Winter Break Family Fun Activities!

Radical Reptiles – Dec. 27!

As we wrap up another year (where did that time go!?) and we enjoy the holidays with time off work and in the good company of family and friends, it is a perfect time to learn more about these “creepy” critters (and other animals) and the very special place they occupy here at River Legacy Park and the Science Center. And, with that in mind, we invite you to River Legacy Living Science Center’s Winter Break Family Fun! From December 26 to December 28, you get to learn more about Magnificent Mammals, Radical Reptiles, and Creepy Crawlers. Get up close with some of our mammals, reptiles, and invertebrates followed by a related craft with time slots ranging from 10:30 am, 11:30 am and 1:30 pm. For more information on how to purchase your admission, you can visit www.riverlegacy.org/calendar or to check out a complete schedule of activities, click here. We hope to see you there!

Creepy Crawlers – Dec. 28!




Hibernation or brumation?

How do animals survive the winter? Winters at River Legacy tend to be milder than in most places around the country because of our location. Still, there are periods when the temperature drops to well below freezing and, sometimes, lingers there for days. Snow and ice events are also expected at least a couple of times during the winter.

Birds have adaptations for surviving the winter that are unique to them. We will talk about them in an upcoming post! For now, we are going to be focused on mammals, reptiles, and amphibians. All of these groups go into a state of dormancy during which they stop growing, grind their physical activities to a halt, and their metabolism significantly slows down. But there are differences in how each group does it.

Hibernation refers to the process mammals go through whereas brumation applies to

Reptiles, such as this red-eared slider (Trachemys scripta elegans), brumate during the winter

reptiles and amphibians. During hibernation, mammals go into a full state of sleep. They slow their breathing and heart rate down to almost full stop and rely on fatty deposit for their energy during this time. They do not wake up from hibernation at all until spring arrives. How do they get their fatty deposits? By eating more and more in the fall. Bats are really the only group that lives at River Legacy that truly hibernate. Other River Legacy mammals such as bobcats, skunks, fox squirrels, coyotes, raccoons, and opossums do not hibernate and instead just seek shelter in someplace warm and do not come out very much OR are able to be fairly active while winter lasts.

Bats, such as this Eastern red bat (Lasiurus borealis), are the only River Legacy group of mammals that truly hibernate.

Brumation, on the other hand, is the process by which reptiles and amphibians survive the winter. During brumation, these animals slow down as well but not to the point of almost stopping heart rate and breathing altogether. One key difference between brumation and hibernation is the fact that brumating animals are able to wake up from time to time in the middle of the winter. This is known as punctuated activity. Why do they need to wake up from time to time? Unlike mammals, which can survive the winter without water, reptiles and amphibians need it periodically. Another key difference is found in the method by which the animals obtain their energy. Mammals, as mentioned, rely on fatty deposits. Reptiles and amphibians instead use glycogen for their energy needs. Reptiles also can survive with very little oxygen during brumation because of this glycogen storage. Examples of River Legacy reptiles and amphibians that brumate include frogs, toads, snakes, and turtles.

If you would like to learn more about the winter adaptations of mammals and reptiles, we invite you to join our Winter Break Activities that are going to take place from December 26th through the 28th. For more information, please visit www.riverlegacy.org/calendar. We hope to see you there!


Recent Bobcat Sightings

Bobcats (Lynx rufus) are well-known inhabitants of our woods! These cats are usually very secretive but, every once in a while, they are spotted walking openly on our paved trails where people can see them. Unlike most mammals, bobcats are still active despite the increasingly colder days. During fall and winter, they become more diurnal as their prey (rabbits and rodents, mainly) is more active at daylight during those seasons. So, it is possible that more bobcats are going to be seen in the next coming weeks and months. Bobcats, in general, are not aggressive species. It is incredibly rare for bobcats to present danger to people. Nevertheless, here are some things you should know if you happen to encounter a bobcat:

  • Stay within a reasonable distance of the bobcat. If you start getting too close to it, it might think you present a threat. Naturally, it would want to defend itself.
  • If the bobcat starts to walk toward you, which is incredibly rare, slowly start backing away. It is important that you do not run as this might scare the bobcat.
  • Do not touch or attempt to feed the bobcat. Bobcats are wild animals and you always want to minimize opportunities for them to bite. As it is the case with most wild mammals, wild bobcats may be rabid at times. Feeding any wild animal can cause harm to the animal, and there are plenty of food resources in River Legacy Park.
  • If a bobcat decides to walk by you, as long as you do not try to kick it or make sudden movements, the bobcat will just continue on its way.
  • Always have your pets on a controlled leash. The last thing you want is any altercation between a wild bobcat and your dog.
  • Be sure to take a picture and/or video of your bobcat encounter from a safe distance!

Seeing bobcats is a neat experience and if you find yourself in that situation and, as long as you follow these precautions, you will be able to enjoy being in the presence of these wonderful cats!


Bobcat (Lynx rufus) seen near the entrance of River Legacy Living Science Center last Saturday, November 10th, 2018!

Devil’s Cigar – A River Legacy Icon

Autumn is in full swing and this is the prime season for finding the sometimes elusive devil’s cigar mushroom (Chorioactis geaster). This mushroom is a very special mushroom because it can only be found in certain counties in Texas (Dallas, Hunt, Denton, Collin, Tarrant, Travis, Hays, Guadalupe) as well as two locations in Japan (Nara and Miyazaki prefectures). Tarrant county, of course, is the home of River Legacy!

This mushroom is found growing on or right next to stumps or dead roots of cedar elm (Ulmus crassifolia). It does not grow on any other tree here in Texas. In Japan, it has been seen growing on oak trees (Quercus spp.) as well as Japanese sapphireberry (Symplocos myrtacea). It essentially looks like a dark brown cigar but changes its appearance once it opens up to release its spores. When it does that, usually a hissing sound can be heard and eventually the mushroom looks like a star. This is why it is also known as the Texas star mushroom!

Mycologists (scientists who study mushroom and related organisms) do not yet know why it is found only in Texas and Japan. A 2004 genetic study showed that the two populations have been separated since at least the early Miocene (roughly 19 million years ago!) This rules out the possibility that humans could have moved from Texas from Japan or vice-versa. Therefore, it is still not known why it has a disjunct distribution. Just another interesting fact about this mushroom!

The devil’s cigar fruiting body usually appears between October and April since it prefers somewhat cooler and wetter weather. This year, it appears that the rain we have had for the past month is creating good conditions for it. We invite you to take a look around River Legacy Park and the trails around River Legacy Living Science Center to see if you can find a devil’s cigar fruiting body. Look around dead stumps of cedar elm trees. No worries if you can’t find it; You can always visit our Discovery Room, where you can interact with a replica of a devil’s cigar and hear for yourself the hissing sound it makes when it releases its spores!

Devil’s Cigar before opening.

Just starting to open.

Fully open.




Why is water important anyway?

Water is a vital resource for life. We have all seen or heard this statement since we can remember. But, what makes water unique for living organisms, from humans to blue whales to bacteria to mushrooms?

While entire articles and books can be written on the subject, here are just a few facts that make water essential:

  • Water has the amazing ability to carry out a vast amount of chemical processes in contrast to many other liquids because of its chemical structure. This allows for humans, plants, and animals to undergo all of the processes they need for survival, from digestion to respiration to photosynthesis. No other liquid would allow for ALL of these to take place.
  • Water prevents things from becoming dry. Since most organisms are majority water, this is key for survival in harsh conditions such as the desert. Without it, animals and plants would literally dry up and harden, dying in the process.
  • Water actually becomes less dense as it freezes. This is something unique to water and it is the primary reason why ice floats. Without this property, our planet’s weather would be drastically different, affecting all life on Earth.
  • Water can absorb a lot of heat before it actually starts heating up in comparison to other liquids. This is the reason why areas where there is a massive body of water nearby tend to be cooler than inland areas (for example, cities by a lake or the ocean). This also makes water an incredibly effective cooling mechanism.

The list goes on and on. Water is constantly being cycled; it goes from the clouds in the form of rain, to the plants and animals in the ground and to reservoirs, lakes, and streams. From there, it either continues to flow until it eventually makes its way into the ocean or it goes to our homes for consumption after a rigorous purification process. Water from our homes eventually rejoins the cycle. All water then ends up in the ocean where it can evaporate into the atmosphere, ready to fall back down as rain. Despite this seemingly never-ending cycle, at the end of the day, water is a finite resource. There was a time when our planet did not have any water and that happening again in the future cannot be ruled out. Therefore, it is very important that we conserve water. Conserving water is also financially smart in the long-run, both for cities and people’s homes.

If you would like to know more about the purification process water goes through, allowing us to be good water conservationists, we invite you to our first Conservation Saturday event at 11 am, Sept. 22. There will be a family-friendly presentation on water conservation, and families will have a chance to create a water bottle water filter. Spaces are filling up quick, so if you would like to sign up, please call 817.860.6752 to RSVP. We hope to see you there!

Spider venom!

Last year, we talked about spiders and their benefits to nature. Today, we revisit spiders to talk about a very interesting trait they have – their venom. Almost all 46,000 spider species have venom. Fortunately for us, there are only a very few that can actually harm people. In our area, there are only two types of spiders of concern: the black widow and the brown recluse spider. Black widows are distinctively black and have a red or orange shape on the back of their belly while brown recluses tend to have a violin-like shape on the back of their thorax.

Spiders primarily use their venom to paralyze prey so they can eat it. The venom is injected into the insect through the spider’s fangs. Spider venom usually is one of two types. Certain spiders produce neurotoxins, which attacks the nervous system of the prey. Other spiders produce cytotoxins, which help in turning the prey into liquid form. This makes it easier for the spider to consume it. In many ways, spider venom is not that different from snake venom.

If you would like to watch a spider eat, we invite you to our public feedings on Fridays at 4:30 pm to see our Texas brown tarantula (Aphonopelma hentzi) eat in his exhibit. Usually the venom will not be seen, but you can be assured the spider is using it to eat its food!

Left: Our Chilean rose hair tarantula eating a cricket. A venom drop, in white, can be seen on the right side of the mouth.

World Lizard Day

Green anoles











World Lizard Day was celebrated on Aug. 14. Herpetologists, pet owners, and nature enthusiasts commemorate this special day every year by increasing awareness about these amazing scaly animals, learning more about them and showing them appreciation. Here at River Legacy, we join in that celebration by sharing our knowledge of them and inviting you to appreciate them.

There are around 6,000 species of lizards alive in our world. Together with snakes, they form a group of reptiles known as the Squamates. They are cold-blooded, scale-covered animals that have generally four legs, ear holes and eyelids. The latter three characteristics are mainly what distinguishes them from snakes. The largest lizard in the world is the Komodo dragon (Varanus komodoensis) found in Asia and the smallest one is the dwarf gecko (Sphaerodactylus ariasae) found in the Caribbean.

In Texas, there are several species of lizards. Here at River Legacy, the most common include several types of skinks (Family Scincidae), the Texas spiny lizard (Sceloporus olivaceus), the green anole (Anolis carolinensis), and the Mediterranean gecko (Hemidactylus turcicus). While the Mediterranean gecko is not a native to the area, the other three are.

The Science Center’s wildlife ambassadors include skinks, green anoles and a bearded dragon. You can also spot anoles, Texas spiny lizards and skinks as they dart across our trails. This is the time of year they are out and about. You can find them on top of decaying logs or basking on a fence, bench, or tree trunk.