Nature Notes

Spring time is here! Spring officially started on March 20. This is the time when the landscape will be changing slowly but surely. Expect to see more flowers blooming, deciduous trees regrowing their leaves, and more green overall. Reptiles and amphibians will start to come out more and more. This will likely mean an increase in the number of turtles found walking on the forest floor or on logs, in ponds, creeks, and other bodies of water as well as an increase in lizards found on trees, logs, and fences. This can also mean more snake sightings and encounters. Please refer to earlier posts in this blog for what to do if you see a snake. Different birds will also start to appear across River Legacy as spring migration is beginning to take shape.

The reason for all these changes mainly have to do with temperature differences and water and food availability. Spring time brings about much warmer temperatures. This indicates to certain animals that their brumation (for certain cold-blooded animals) and hibernation (for certain mammals) times are over. Warmer temperatures also awake certain plants from their dormancy. Normally, spring also brings more rain, sometimes in the form of storms. Water helps with seed germination, causing more plants to start appearing. More plants mean more food for herbivores, which means more food for omnivores and carnivores as well.

Spring is a perfect time to enjoy and learn about nature with us at River Legacy Living Science Center. We invite you to all of our spring events coming up:

• Our FREE Earth Day festival is Saturday, April 14 from 10 am to 2 pm . This is a family festival, open to the public, where you can learn much about Earth Day and why conservation is important while enjoying nature walks, crafts, activities and hands-on demonstrations.
• Nature Walks are held on the second Saturday of every month and are great opportunities to explore the seasonal plant and animal changes in the park. Our next Nature Walk will be Saturday, May 12th. Space is limited, so please call 817.860.6752 to reserve your spot.
• We are partnering with the Arlington Water Utilities Department to host a rain barrel making workshop from 6 to 8 pm, May 8 at River Legacy Living Science Center. This program covers the basics and benefits of rainwater harvesting and the effects stormwater has on the environment. Participants will learn how to collect and utilize rainwater at home and have the opportunity to construct their very own 55 gallon rain barrel. Cost is $50. Register online here. 

Have you ever wondered why, during winter, some deciduous trees (trees that let their leaves fall to the ground) still have a clump of leaves on a branch? It turns out that these leaves do not belong to the tree; they actually are a different plant, a mistletoe. Mistletoe plants occur in every continent on the planet and they belong to different families and genera. The most common found mistletoes in North America, including here at River Legacy, are species that belong to the genus Phoradendron.

Mistletoe plants are hemiparasitic plants, meaning they are parasites of trees most of the time but can still undergo photosynthesis. Photosynthesis is the regular process through which the majority of plants produce their own food, using sunlight, water, and carbon dioxide to produce nutrients. They attach themselves to the tree at the stem and start absorbing from the tree or shrub. Though they are considered pests and can damage significantly and even kill trees, mistletoe plants may not be all that bad. Research suggests that some mistletoe species can actually help the tree disperse its seeds, as it attracts birds that eat the fruit of the tree.

As we approach the final days of winter, walk the trails at River Legacy and take a look at the leaf-less trees and see if you can spot any mistletoes on a tree or shrub.

Did you know that most birds’ bones are hollow and filled with air sacs? Did you know that the fastest member of the animal kingdom is a bird, the peregrine falcon (Falco peregrinus)? Did you know that birds are actually descended from dinosaurs? Did you know that River Legacy is home to more than 225 species of birds for all or some parts of the year? There are countless of interesting facts about birds and this weekend is the prime time to learn more about them.

That is because the Great Backyard Bird Count is here! The Great Backyard Bird Count is a global, annual event that takes place usually around this time in February. It is a project sponsored by the Cornell Lab of Ornithology and the National Audubon Society. Citizen scientists are encouraged to take at least 15 minutes (can be more though!) to count birds from today, Friday, February 16 through Monday, February 19, 2018 and submit their checklists online. Anyone can join in, from amateur birders to experts and researchers in the field of ornithology. You can find more information about how to submit a checklist by visiting gbbc.birdcount.org or the National Audubon Society website.

The River Legacy Living Science Center is proud to participate in this global effort and, to that end, we are hosting our annual Great Backyard Bird Count Festival tomorrow, Saturday, February 17 from 10 A.M. to 2 P.M. This event for the entire family is free. You can learn more information about birds and take part in bird hikes and counts and enjoy crafts, games and activities to celebrate our feathered friends. Find more information here. We hope to see you tomorrow!

Great blue herons (Ardea herodias) are River Legacy native birds that can be seen year-round. Though they are a rather common sight near bodies of water and most people are familiar with them, did you know these interesting facts about them?

• Great blue herons are the largest North American herons! They can be up to 54 inches tall and have a wingspan of up to 79 inches.
• Despite these measurements, they barely register a weight of about 5 to 6 pounds. This is mainly due to the fact that their bones are hollow, a characteristic they share with most birds.
• Because of special neck bones, they can be incredibly fast hunters at a distance. This is especially striking when they are hunting for fish.
• They build their nests usually on trees in colonies. These large colonies can, sometimes, have up to 500 nests!

Next time you are taking a walk through River Legacy, be on the lookout for great blue herons in a pond or creek. In addition, our annual Great Backyard Bird Count Festival is coming up on February 17th from 10 A.M. to 2 P.M. There will be bird hikes throughout the event and perhaps a great blue heron can be spotted that day! You can also learn more interesting facts about other species of birds. More information about the event can be found here.

When the thermometer drops to below freezing, there is a plant found at River Legacy that forms captivating ice structures on its body. The aptly named frostweed or the white-crowned beard (Verbesina virginica) forms ribbon-like ice structures when the stem opens up during a freeze and the sap comes out of the plant frozen. This only seems to occur at the base of the plant, near the ground. These formations are sometimes also referred to as crystallofolia, meaning “leaves of crystal.” There is no evidence to suggest that the plant is permanently damaged by this phenomenon. These past couple of weeks, as the area succumbed to one of the coldest winters in years, some frostweed ice “ribbons” were observed in the woods of River Legacy. Winter is not over yet. If there is another freeze, it is possible that these plants could display their ice structures once again. But, if you do miss them this winter, do not forget to come back next winter and take a walk through the trails at River Legacy to see them!

Winter is in full swing at River Legacy and plants and animals have to adapt to the changing season. Winters tend to be mild in North Texas but temperatures still drop to freezing and below, as it has been the case for a few days in the past couple of weeks. How do the animals and plants survive the cold?

It turns out that many species have unique adaptations that allow them to survive the harsh conditions of this season. Let us take plants, for example. Annuals, plants that live for only one growing season (usually spring to fall), survive the winter as seeds in the soil. The soil tends to be warmer than the surface, which allows for the seeds to survive. Perennials, plants that live year after year, survive in a different manner. They can go into a state of dormancy (trees losing their leaves, for example), which is akin to mammal hibernation. In addition, if it gets too cold, some plants can produce chemical substances that lower the freezing point of the fluid inside their cells and in between their cells, so that ice crystals do not form and kill the plant from the inside.

Animals too have to cope with the freezing and sub-freezing temperatures. Some mammals hibernate, meaning they basically shut down for the entirety of winter and sleep in a warm place. Others can find a nice den and stay there most of the time for the coldest part of the winter. Fox squirrels (Sciurus niger), a very iconic River Legacy mammal, will build dreys and also share their dens with other squirrels to keep each other warm. They also prepare in advance by increasing their food consumption and caching in the fall so that they have enough from which to survive in the winter. Reptiles, being cold-blooded, cannot survive drastic drops in temperature so they find a warm shelter and go into a state similar to hibernation called brumation. The difference is that reptiles can wake up from this state if a warm winter day happens to arrive. Aquatic reptiles and fish will hang out at the bottom of their habitat (creek, pond, river, etc.), where it is warmer and slow down their metabolism. Birds will either migrate, hunker down, get together in groups, shiver to increase body temperature, and cover their feet with their downy feathers when sitting down.

Next time you use the walking trails at River Legacy when it is cold, think about the animals and plants all around and their incredible adaptations that enable them to survive!

Box turtles are small turtles in the genus Terrapene. They have a dome-like shell that has a hinge at the bottom, allowing the turtle to close its shell completely in order to escape predators. Males are characterized by having usually red or orange eyes while females have brown eyes. River Legacy Park and the woods adjacent to River Legacy Living Science Center are home to two species of box turtles: the three-toed box turtle (Terrapene carolina triunguis) and the western ornate box turtle (Terrapene ornate ornata).

The three-toed box turtle is a subspecies of the common box turtle (Terrapene carolina). As the name indicates, this turtle has three toes on its back feet. These turtles can be found walking through the forest looking for food including vegetation, small insects, mushrooms, fruits, earthworms, and snails. The males of this turtle can sometimes exhibit orange or red spots on its throat and head. Three-toed box turtles will bury themselves underneath the leaf litter during the dry season to try to conserve moisture.

The other River Legacy box turtle, the western ornate box turtle, is a subspecies of the ornate box turtle (Terrapene ornata). It is characterized by ornate patterns on its shell, which are usually bright yellow. In contrast, the three-toed box turtle does not have these patterns. Males of this species tend to be a bit smaller than the females and also tend to have a thicker tail. Ornate box turtles tend to prefer grassland or prairie habitats rather than dense forest though they will also venture into the woods.

Box turtles can live up to their 30’s, which is fairly long for a small animal. As you walk through the trails of River Legacy, keep your eyes open and you might spot a box turtle walking through the woods. In addition, do not forget to visit River Legacy Living Science Center to see a three-toed box turtle in our exhibit hall!