Sensory Serenity

Written by: Mollie Ripple, Social Media Coordinator

John Burroughs once said, “I go to nature to be soothed, healed, and have my senses put in order.” Like Burroughs, many of us often feel the therapeutic benefits of engaging our senses in nature. But how can this be understood scientifically?

When our bodies are too aroused or not aroused enough to engage with our environment properly, we call this dysregulation. It can manifest as an angry outburst, impulsivity, crying or feeling overwhelmed, and it impairs our ability to deal with stress, manage our emotions, and focus. The ability to change our level of arousal to engage in our environment effectively is called regulation, and one way to do this is through our senses. 

We have seven sensory systems: Sight (vision), Smell (Olfactory), Taste (Gustatory), Hearing (Auditory), Touch (Tactile), Vestibular (Movement), and Proprioception (Body Position). When we tap into these senses, we can increase or decrease our arousal to reach sensory regulation. Even better, we can practice these techniques outdoors and get the added benefits that time in nature provides us.

Here are a few ways we can engage each sensory system through natural materials and activities:

  • Sight: Stargazing, Bird Watching, Going on a scavenger hunt in nature to spot various plants and animals
  • Smell: Stopping to notice the scent of recent rain, wild berries, lavender, or pine
  • Taste: Consuming cold water, herbal tea, or fruit from a tree (that is approved as safe by an adult)
  • Hearing: Listening to the birds sing, a running stream, or the rain
  • Touch: Playing in the sand or soil, Walking barefoot through the grass, Petting your beloved animal, or Stroking the bark on a tree
  • Vestibular: Bicycling, Swinging, Running, or Playing on the playground
  • Proprioceptive:Heavy Work” activities like crawling through the grass, pushing/pulling a wagon, or jumping up and down on a trampoline

A study published by Chang & Chang in 2010 states, “many parents and teachers said that their children and students [were] more stable after doing [these] kind[s] of activit[ies].” So, the next time you or your child feel dysregulated, try getting outdoors and engaging your sensory systems to be soothed and healed in a way only nature can.

Chang, Y. Y., & Chang, C. Y. (2010). The benefits of outdoor activities for children with autism. 

Unpublished manuscript, Department of Horticulture, National Taiwan University, Taipei, ROC.

Spring in North Texas

Written by: Dr. Ellen Edwards-Ravkind, Naturalist Manager

Spring has arrived in North Texas! The days are getting longer and warmer while the nights are still cool. Our trees are covered with fresh, spring-green leaves. The Redbuds and Mexican Plums have already blossomed, but the Oaks, Hackberries and others are still producing more pollen than most people would like. Yellow pollen covers just about everything, and allergy sufferers have had enough. Roadways, meadows, and fields are exploding with color like a French impressionist painting with colors of blues, pinks, magentas, yellows and many more.

This spring, take some time to walk the trails at River Legacy. How many kinds of wildflowers you can identify? Strolling around the pond at the Nature Center you will see a sea of blue! These are the iconic and cherished Bluebonnets, adopted as the official state flower of Texas in 1901. Many residents and visitors alike dress in their Sunday best to have their photos taken in the sea of Bluebonnets. Columbines, Spiderworts, Pink Evening Primrose, Winecups, and Indian Paintbrushes are also blossoming. Look closely and you will find Purple Coneflowers, Mexican Hats, Prairie Coneflowers, and many others!  

You might wonder why there are so many beautiful wildflowers in our park, or how can you have some of these beautiful native wildflowers grow in your yard. It is not as difficult as you might imagine. Native Texas wildflower seeds are readily available. Seeds should be planted within the year harvested to have the best chance to germinate. Some seeds might last longer, but the germination odds decrease. Typically, in North Texas, the best time to sow the seeds is in the fall which gives them a chance to go through our weather cycles to help them induce germination. Rain, cold snaps, and soil abrasion all help with germination. Smaller seeds can be scattered on top of the soil. Larger ones might need to be buried, but not too deep which can prevent them from growing into their beautiful flowers. Usually, about 1/8 to 1/16 inch is more than enough. It is also important to clear the area of invasive plants such as Johnsongrass which can “choke” out your desired plants. It is not too late to plant seeds, but most of your wildflowers will not bloom this year. 

These wildflowers will produce seeds after blossoming and pollination. Make sure to give the seeds time to ripen before you mow or “deadhead” your plants. Simply put, deadheading is a process where old growth and seed heads are removed from the plant individually to either collect the seeds or spread them to new areas. Make sure the stems have turned brown and wear gloves to prevent skin irritation from cutting the dried plants. Leaving some of the dried, hollow plant stems will also provide a home for some of our solitary pollinators during the colder seasons. 

If you continue this process, your gardens will continue to produce these beautiful North Texas wildflowers. Sharing your seeds helps to spread the beauty of Texas wildflowers with others.

Share the excitement with us! If you have a wildflower garden or simply some awesome wildflower photos we’d love to see and feature them!

Send your photos to

A Forest’s Purpose

Written By: Sarah Morris, Naturalist

As you walk around River Legacy, you’ll find a large variety of beautiful trees, such as the American elm, live oak, eastern redcedar, boxelder, and many more. These trees are shade tree species that are highly beneficial in providing heat island reduction, air pollution removal, and stormwater runoff control.

Unfortunately, during the storm on March 3rd, winds picked up to 80mph and many trees were destroyed by the strong winds or by the collapse of other trees. This storm damaged the trails around the Nature Center and the AISD trail that we use for field trips and educational programs.  The storm caused much devastation to the trees, which affected animal homes, the soil, and created dangers to the public. We lost old and important trees that had been used as key learning locations during educational programs since the Nature Center opened in 1996. 

Although this was a sad event, it was also a great reminder of why trees and forests are so important and they really are a bigger deal than you might think! Trees are known as “the lungs of the Earth” because they absorb many pollutants and filter the air. They also, of course, absorb CO2 (carbon dioxide) that’s in the air and let out O2 (oxygen) for us to live and breathe. 

Trees improve water quality, and reduce flooding and erosion. When raindrops hit leaves and branches, it slows the flow of rainfall which helps prevent flooding. Trees also absorb water through their roots and hold the soil in place to prevent erosion. It’s estimated that 100 mature trees can absorb about 100,000 gallons of rainfall per year. That’s AMAZING!

Trees create habitats for plants and animals which allows biodiversity and pollination to occur. Without our pollinators, we wouldn’t have nearly the amount of access to food/crops that we have now and over 100,000 species of plants would become extinct. Have you watched the Bee Movie? Yeah, they weren’t exaggerating. 

So yes, trees and forests are a big deal! As Earth Day approaches, we will be reminded of all the great things nature gives us, and trees are a huge part of that! They provide so many benefits to humans, plants, and animals. Most of all, trees and other variables are necessary for our survival as a human race. We need to take care of what we have now to have a brighter and greener tomorrow. 

The River Legacy Nature Center offers countless opportunities for people of all ages to learn about nature, and River Legacy Park is just a short hike away to surround yourself in it! Come to our Earth Day celebration, Saturday, April 1st from 10:00 am-2:00 pm at the Nature Center. There will be sustainable DIY crafts, children’s activities, guided hikes, storytimes, and plenty of opportunities to learn to be a great environmental steward.

Join the race to make the world a better place.

Nature’s Classroom

Written by: Sherrie Ripple, Director of Education

The weather’s warming up, flowers are blooming, and animals are becoming more active. It’s the perfect time to gather your family, go outside and enjoy the best classroom of all – NATURE!

We know playing outside in nature is good for us physically, mentally, and socially. According to one study published in 2019, spending just two hours a week in nature is correlated with significant increases in health and well-being (White et al., 2019). So, imagine if you spent even more time outdoors! Here are some fun family activities to plan for the next time you are outside and there’s even a bonus – these activities all promote STEM (Science, Technology, Engineering, Mathematics) concepts:

● In your backyard, put some water in a plastic container to let your children explore with different materials (a penny, foil, a Lego, a cup, a plastic spoon, a metal spoon, or a leaf). What makes some materials sink in water and others float? Ask them to make a prediction about some of the
materials, then follow up with questions about what happened and why? Most children, and even some adults, are often surprised by the outcome!
● Start a garden. Discuss what you are going to plant and why. What do plants need to grow? Encourage your child to keep a journal along the way. Does it look, smell, feel or taste different?
● Go on a nature scavenger hunt (you can find some on our @riverlegacynatureschool Instagram Story Highlight – Activities). This is such a fun way to explore STEM concepts!

  • Look for a bird’s nest. Birds are expert engineers. Their ability to build nests that support and protect their eggs and chicks is an adaptation that has helped them survive and thrive within their habitat.
  • If your hunt leads you near a playground, look for a see-saw (a simple machine called a lever) or a ramp (a simple machine called an inclined plane). Both are very basic mechanical devices used to multiply force. If you ride bikes during your scavenger hunt, you can also mention gears and how they help you get to where you’re going faster and easier.
  • Make sure to add rocks to your scavenger hunt. Stop and examine them. They are one of the first known technological inventions!
  • Lastly, clouds! Find a great place to lie down in the grass and observe them. What are clouds? Discuss the water cycle and how water is essential to every living creature. Relax for a while and let nature take its course.

If you enjoy these ideas and want more, stop by the Nature Center from 9 am-5 pm Monday through Saturday. Our wonderful group of educators is happy to help you discover more ways to spend time in nature!

White, M.P., Alcock, I., Grellier, J. et al. Spending at least 120 minutes a week in nature is associated with good health and wellbeing. Sci Rep 9, 7730 (2019).

The Beauty of Citizen Science

Written by: Jorge Garcia, Naturalist

Life list? eBird? Birding? Bird count? Citizen scientist? What in the world do any of these terms mean? It’s very possible that you have heard of some or all of these terms before. But, if you don’t know what they mean, that’s ok. Here at River Legacy Nature Center, we will be taking part in the annual Great Backyard Bird Count – an annual, global event that will help shed light on some of these terms. The GBBC, shorthand for the Great Backyard Bird Count, is one of the largest citizen science projects in the world.

During a 4-day period in mid-February, thousands of regular people around the world observe, count, appreciate, and celebrate our feathered friends. Data collected is then submitted to a database and, eventually, is used to help guide conservation efforts and to help ornithologists better understand all facets of the avian world.

The GBBC has a fascinating history and powerful impact. It started 25 years ago, back in 1998, as an initiative by the Cornell University Lab of Ornithology, one of the world’s leading ornithological research institutions and the National Audubon Society, one of the largest and most-renowned bird and nature conservation organizations in the world. They coordinated one of the first ever internet-based citizen science projects. In 2009, Birds Canada joined the effort as the event took on greater popularity and spread across the North American continent. By 2013, the effort went global and has steadily grown in many countries over the years. In 2022, nearly 400,000 birders in 192 countries were able to observe and count 7,099 bird species – representing an astounding 3/4ths of all bird species currently known to science. River Legacy Park and the River Legacy Nature Center are considered to be one of the largest hotspots of bird diversity in Tarrant County and one of the largest in the Dallas-Ft. Worth region. Birders from all over the world, including well-known individual birders within the birding community, have visited River Legacy to enjoy its avian diversity.

So, how can you participate in the Great Backyard Bird Count? The count runs from February 17th through the 20th. You can participate from the comfort of your own backyard for at least 15 minutes throughout that weekend. However, we invite you to participate in person with us and other like-minded citizen scientists. On February 18th, 2023, we will be hosting the Great Backyard Bird Count event here at River Legacy Nature Center from 10 AM to 2 PM. There will be designated areas where you will be able to participate in counting and observing birds. Master naturalists will be on-site to help explain the event, help ID birds, and answer questions you may have. If you’ve never participated in an event like this and don’t know where or how to start, this is a perfect learning opportunity for you! Our master naturalist will help introduce you to the world of birding!

If you are an experienced birder and just want to do your count at River Legacy, you can come too and bond with other birders! Birders of all ages, knowledge, and backgrounds are welcome. In addition to the designated counting and observing areas, we will also have naturalist-led bird walks where you can partake in counting while moving along a designated trail plus a few other activities to celebrate the avian world. We hope to see you at the Nature Center as you spot a northern cardinal (Cardinalis cardinalis), a ruby-crowned kinglet (Regulus calendula), Carolina chickadee (Poecile carolinensis), or pied-billed grebe (Podilymbus podiceps), among many other species!


Fostering the Next Generation of Environmental Stewards

Written by: Shannon Porter, Executive Director

It’s a fact that modern childhood has moved indoors. Neighborhood kids no longer adventure outside to climb trees, catch insects or create outdoor games. On average, American children spend between four to seven minutes a day engaged in unstructured outdoor play (not including organized sports) and as many as nine hours a day in front of an electronic screen.

Many of our youth are tuned out, stressed out and over-scheduled. Last Child in the Woods author Richard Louv calls this Nature-Deficit Disorder. And this is not just limited to kids, as it also affects adults, families, and whole communities. However, youth and adults who regularly spend time in nature enjoy priceless benefits to mind, body and spirit. These include improved physical health as well as professional or academic success through greater capacity for leadership, self-awareness, self-confidence, critical thinking and creativity.

With the shrinking amount of time young people and their families spend outdoors, there has also been a growing concern about who will carry forward the legacy of stewardship handed down to us by Bob Marshall, Aldo Leopold, Rachel Carson, Sigurd Olson, and others. Jacques Cousteau, taking Leopold’s lead, reminded us that we “protect what we love.” If a generation slowly pulls too far indoors, away from backyard forts, mud puddles, bike paths, lakes, and the wildlife and plants, how will they, too, fall in love with wild places? Further, every generation decides what to protect. If we raise a generation of youth who are disconnected from nature, how can we ensure both their good health and the health of the natural world that sustains us all?

At River Legacy Foundation we are working to rebuild a culture of nature connection in our community. While spending time in nature is an important habit, rebuilding a lasting culture of nature connection in ourselves, our families and our communities requires a longer view and deeper commitment. We think seven generations ahead. We ask: What can we do today for the benefit of future generations?

All of our programs provide time to explore the natural world because this is where the taproot of deep connection to the earth takes hold. We intentionally create time for youth to follow their curiosity. They catch damselfly nymphs and water bugs in the pond. Watch squirrels play in the trees. Listen to birds singing. Get muddy. Run wild. Build forts or tree cookie towers. Explore under fallen logs for decomposers. Dig for worms or slugs. Catch spiders and insects. Play in the creek.

While youth believe they are “just playing outside,” recent studies have proven that childhood experiences such as these, and not the more traditional forms of environmental education, directly lead to adults who are active stewards of the earth.

Here at River Legacy, we are committed to guiding learning in nature that fosters empathy, resilience and a deep connection to the environment for the benefit of raising a strong generation of youth, healthy families and communities, and a flourishing planet.

Frilled or Fiction?

The movie and television industry has been around for decades, showing many sides of fiction, non-fiction, documentaries, etc., to the public. Many movies use animals of all kinds for references, ideas for creatures, and to enhance entertainment. For example, Jurassic Park is a well-known movie that helped increase the popularity of dinosaurs for about 30 years. In this movie, we see a dilophosaurus which was a genus of Theropod dinosaurs that lived in North America during the Early Jurassic, about 193 million years ago.  For the Hollywood version of this creature, the frilled lizard was used as an inspiration to embellish the Jurassic Park dilophosaurus which had extra skin that flared out as it does in the picture to the right. In the movie, this dinosaur was large, scary, and could spit out venom to attack its predators and prey and was also one of the dinosaurs that could roam freely around the park. This adaptation of spitting venom out came in handy later in the movie!

Another example of frilled lizards being used as an inspiration can be seen in the early 2000s movie Holes. In Holes, this lizard was known as the “Yellow Spotted Lizard,” a venomous creature inhabiting the arid wasteland of Green Lake and terrifying the campers. The Yellow Spotted Lizard had yellow eyes, red eyelids, and 11 yellow spots on its back… the legend said that if you got close enough to count the spots, you could get bitten and die. Campers at camp Green Lake were quite scared of these reptiles, but at the end of the movie, when Stanley and his pal Zero find the buried treasure, they are covered head to toe with the Yellow Spotted Lizards, yet unharmed

In both of these movies, the frilled lizard (aka frilled dragon) was used as inspiration, but it was portrayed as a scary venomous creature.

So what are the REAL facts about this influential creature?

The frilled lizard can reach lengths of 2-3 feet with a weight of 1-2 pounds. And while the frilled lizard is non-venomous and may not seem nearly as intimidating as what we see in Jurassic Park, the frilled lizard actually has one of the most creative defense mechanisms. This lizard will open a frill around its neck, reaching 12 inches in diameter to make itself look big and scary, it might even open its mouth and hiss. If these defenses fail the lizard runs to safety, moving its legs in a wide circular motion and not looking back until they reach a tree. This peculiar motion landed them the nickname of “Bicycle Lizard”. 

The frilled lizard is an impressive and eye-catching reptile to observe, and did you know we have one at the Nature Center right now? If you’d like to see a frilled lizard in real life make sure to check out our visiting exhibit Here Be Dragons: From Lizards to Legends. This exhibit will only be here until February 11, 2023 so stop by soon!

Lizards and Tail-loss and Regeneration, oh my!

Can you imagine all the things we could do if we had a tail? Well, we once did have a tail. In utero, babies start with a tail; tails get smaller and fuse into our vertebrae, creating our “tail-bone” around eight weeks. We miss out on some extraordinary abilities once we no longer have a tail. For animals, having a tail can provide balance, navigation, communication, mating rituals, marking territory, and defense. 

Let’s talk about defense.  Some lizards are notorious for losing their tails (autotomy) when humans or other animals attempt to catch them.  I remember catching a green anole in my backyard as a kid. I was so excited to catch it but saw its tail come off as I grabbed it. The tail was then on the ground, still kind of wiggling around. As a child, that can seem pretty scary or even creepy, but it’s interesting that the lizard has this ability. Lizards have learned that they can save themselves from predators through the art of distraction. 

When predators chase lizards, their tails can detach from their bodies; as the tail wiggles around on the ground, it directs the predator’s attention to the tail instead of them. Juvenile skinks (as pictured on the left) have a bright blue tail that is easily noticeable to predators. Although that might sound counteractive, luckily for skinks, their tail is expendable, and the skink can walk away unharmed. Once the tail has dropped, the lizard can regenerate its tail. However, the regenerated tail isn’t a replica of the original. 

Now, if lizards can release their tails when faced with a predator, what happens when they encounter another one? How many times can a lizard release and regenerate its tail? Regeneration requires cells that will develop into tissues that become new muscles, cartilage, tendons, and eventually a regrown tail. Most lizards can live about 4 years or so, depending on the food, water, shelter, and predators. Depending on how big the lizard is and how healthy they are, it can take anywhere from a month to over a year to have a tail regenerate. So, if the lizard survives those months without a tail as it goes through the regeneration process, one single lizard can potentially drop and regenerate a few tails in its lifetime. 

Next time you visit the River Legacy Nature Center and walk the trails, look for lizards like the ones in the images below. If you notice a brown patchy tail that doesn’t seem to match the rest of the body, or just looks like they’re missing a tail, they are in the regeneration process, and a new tail is on the way. 

There is so much more to learn about lizards! Our upcoming visiting exhibit Here Be Dragons: From Lizards to Legends will feature 6 live lizards so visitors can learn about these legendary creatures up close and personal. Mark your calendars for November 19th and get ready to explore different realms, encounter living legends, and discover unique artifacts at the River Legacy Nature Center.

Visit our website for more details

Written by Sarah Morris, Naturalist.

Cicadas: What is up with that sound?

Around this time of the year, the woods of River Legacy start producing a very peculiar sound. It is loud and generally described as a high-pitched buzzing sound. The origin of this sound is one of the most intriguing and well-known inhabitants of River Legacy: the cicada. It is quite likely that you have heard this sound before. It forms an integral part of the summer experience in North America. Let’s delve more into cicadas and the sound they produce.

Cicadas are insects that belong to the order Hemiptera, a very big and diverse order of insects known collectively as the “true bugs and relatives.” This makes cicadas distant relatives to insects such as aphids, stink bugs, shield bugs, leafhoppers, and bed bugs–yes, those bed bugs! There are roughly 3,000 species of cicadas and they inhabit every continent except Antarctica. In North America, there are about 200 species of cicadas. The most common species of cicadas belong to the genera Tibicen, Megatibicen, Hadoa, and Diceroprocta and are known as the dog-day cicadas. These are considered to be annual cicadas.

This means that they have a life cycle that lasts anywhere from 2 to 5 years, in general. On the other hand, species belonging to the genus Magicicada are known as the periodic cicadas, because their life cycle is very different from the others. These cicadas have either a 13-year or 17-year life cycle, so broods can remain underground for years until it is time for them to emerge. The vast majority of these cicadas can be found east of the Mississippi River. Most of the cicadas in Texas are annual cicadas though there are some members of Magicicada found in counties along the Red River, bordering Oklahoma.

The cicada sound is essentially a mating call produced by the males in order to attract a female cicada. The sound can also be used to announce an individual’s territory. The origin of this sound can be traced back to a special organ that few insects have: the tymbal organ. The male cicadas possess 2 of these, which are circle-shaped ridged membranes found on the back and side of the 1st abdominal segment of the cicada. The muscle that attaches to the tymbals contracts and bends the tymbals, which creates a clicking sound. When the muscle relaxes, they go back to their previous form. The tymbals contract so frequently (120 to 480 times a second) that it appears as a long, continuous sound to the human ear. There are air sacs in Cicadas that amplify the sound to produce the iconic cicada buzzing sound!

Cicadas are very special insects with an amazing adaptation that has made them world famous. As you take a walk through the River Legacy this summer, remember how the cicada sounds are being made as they graciously cover the woods.


  • Bauer, Patricia. “Why are cicadas so noisy?”. Encyclopedia Britannica, Invalid Date, Accessed 9 May 2022.
  • Evans, Arthur. Field Guide to Insects and Spiders of North America. 1st ed., New York, Sterling Publishing Company, 2008.
  • Abbott, John, and Kendra Abbott. Common Insects of Texas and Surrounding States: A Field Guide. 1st ed., Austin, University of Texas Press, 2020.
  • Drees, Bastiaan, and John Jackman. A Field Guide to Common Texas Insects. 1st ed., Houston, Gulf Publishing Company, 1998.
  • Liebhold, A. M., Bohne, M. J., and R. L. Lilja. 2013. Active Periodical Cicada Broods of the United States. USDA Forest Service Northern Research Station, Northeastern Area State and Private Forestry.

How come there are no blue or green mammals?

Have you ever thought about this? Think about it for a minute. If you were to list 10 mammals off the top of your head – perhaps animals like your dog, cat, an elephant, rat, zebra, skunk, raccoon, opossum, bobcat, or even a coyote – you would quickly realize that the colors of these mammals lack blue and green hues. There are a couple of reasons as to why this is, and why other animals like insects, birds, amphibians, and reptiles exhibit these colors quite often.

The reason has to do with chemistry primarily. First off, let’s talk about what produces colors in living things. Pigments are chemical compounds that are responsible for producing color in the biological world. When pigments absorb light, they reflect back certain wavelengths, producing colors our eyes can perceive. Plants, for example, have many different kinds of pigments with all kinds of peculiar names, such as carotenoids, flavonoids, and anthocyanins. Thousands of these chemicals have been identified by scientists and this is the reason why plants can produce a vast array of colors – from the dominant green leaves, to different shades of bark on trees, to the orange color of a carrot, the colorful fruits and flowers there are and the beautiful foliage colors we see during autumn in temperate latitudes.

When it comes to animals however, things are a bit different. The vast majority of animals simply do not have the variety of pigments that plants do. Specifically, they are not able to genetically produce blue and green pigments. Then how come we still see animals that are those colors? There’s blue butterflies, green frogs, and peacocks are well-known for their blue feathers! Most of these animals produce this color through a phenomenon known as structural coloration, which is the optical illusion of a color, essentially. Small structures of the skin scatter and reflect back light in a way so that only the blue wavelengths reach our eyes. But, in reality, there is no blue pigment doing that. When it comes to green, usually there is a yellow pigment involved with a structural blue coloration.

For instance, when a rough green snake (Opheodrys aestivus), a common River Legacy snake, dies, it turns blue because the yellow pigment is no longer being produced but the structural color is still there. Another way animals are able to produce vibrant colors is by obtaining pigments from their environment, typically their diet. This is how flamingos develop their typical pink to red hue, by eating foods like algae, shrimp, and crabs that have these pigments in them. A similar phenomenon occurs with the northern cardinal (Cardinalis cardinalis), another River Legacy common sight.

Now, let’s go back to mammals. Mammals have not been able to evolve or have lost the ability to implement pigments obtained through their diet to the same extent as other animals have. It happens but not to the same degree. This is why eating something like beets can turn the toilet a certain color when we go to the bathroom but it does not turn our skin purple. When it comes to naturally-produced pigments, mammals really only produce one kind – melanin. Melanin is an important pigment that provides protection against the sun’s damaging UV rays but it also is responsible for the majority of colors in mammalian skin. It comes in two kinds – eumelanin (responsible for black and brown colors) and pheomelanin (responsible for yellow or reddish to brown colors). Very few mammals, like mandrills (a type of African monkey), are able to produce small amounts of blue color through structural coloration.

But, how come no other mammals can? Scientists are not really sure but it may have had to do with the evolutionary history of mammals. Early mammals survived during the Mesozoic era, the golden age of the dinosaurs, by basically not being around them too much in order to avoid becoming food or by not trying to compete with them for the same resources. It is believed that most dinosaurs were active during the day so it is most likely that mammals had to turn to a largely nocturnal lifestyle. This meant that mammals did not have the need to develop adaptations that were not necessary in the night, such as the ability to see a wide range of vibrant colors. If there was no selective pressure (i.e. need) for either evolving structural coloration, pigment formation, or the ability to obtain pigments through diet, then the genes that allowed for those traits disappeared from the mammalian gene pool. The majority of animals today, with the exception of most mammals, have stellar color vision. On the other hand, as a result of their evolutionary history, mammals tend to be color-blind when it comes to blue and green colors. The big exception to this are primates – the group to which humans and mandrills belong. Therefore, it is hypothesized that as a result of all of this, the vast majority of mammals lack green or blue colors on their skin or fur.

What an incredible and fascinating subject to be sure. Next time you take a hike in the River Legacy trails and you come across a mammal – whether it be a squirrel, bobcat, or rabbit – you will know why those creatures are not flashing blue and green at you!