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A few cool critters I've found near the house recently. The first photo is one of the prettiest GRAY TREEFROGS I've seen. As you might guess, gray treefrogs are usually gray in color, Their mottled pattern makes them look like lichens on a tree. However, especially around their breeding season, many of them turn green, like this one. Gray treefrogs typically eat insects, but when they get larger, they will feed on anything that moves, including smaller frogs. Around our house, whenever it rains, the gray treefrogs start singing (singing in the rain!). The second photo is a FIVE-LINED SKINK I found hiding under a rock. Five-lined skinks are common in Missouri, though they are secretive. If you are walking in the woods and hear something scuttling away in dry leaves, it's probably a five-lined skink. The juveniles of this lizard species have bright blue tails, so some people call them blue-tailed skinks. But this name is confusing because many types of skinks have blue tails as juveniles. When a predator attacks a juvenile skink, the skink's tail will break off and wriggle around—the bright blue wriggling thing distracts the predator, allowing the young skink to escape. The third photo is a RED-BELLIED SNAKE. It's probably obvious how it got its name. These harmless little snakes like to snarf up slugs, snails, and earthworms. They have a special adaptation for eating slimy snails—extra-long teeth. These teeth allow the snake to grab a snail's soft body and pull. The snail eventually grows tired of the fight, and the snake actually pulls the snail's soft body out of its shell to consume it. These snakes also have an odd habit of flaring their lips out, which is probably a behavior that exposes their teeth to better hold on to their slimy prey. Isn't it awesome that so many amazing little critters are hanging around underfoot and in the trees above?    Photo Credits: All photos by Stan C. Smith
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Did you know there is a small but beautiful dolphin species that inhabit only the waters near Antarctica? Hourglass dolphins average only about five feet (1.6 m) long, with a stubby beak (snout). They have a striking black and white pattern, with the white on each side of the body resembling a horizontal hourglass. These are the only small dolphins that live in the waters of Antarctica. Like other cetaceans (whales and dolphins), hourglass dolphins swim in pods, sometimes with up to a hundred individuals, though they are usually seen in smaller pods of eight to twelve. They seem to enjoy riding the waves of fast-moving ships. They also feed at the surface (on fish and squid). These surface habits make it easier for scientists to locate hourglass dolphins to monitor their numbers. However, the last sighting survey was done in 1987-1988, almost forty years ago. At that time, scientists estimated the population to be about 144,000. The numbers have probably declined slightly since then, but these dolphins are relatively safe simply because few humans travel to Antarctica. If you haven't guessed, human presence is usually bad for whales and dolphins. Unfortunately, in the coming years, climate change may threaten these dolphins. Because of the distinct black and white pattern, whalers originally referred to hourglass dolphins as "sea cows" or "sea skunks."  I do it all the time, and I’ve seen other people do it. We are trying to remember something, or trying to come up with a creative idea, or trying to think of what to say, so we tilt our head back and look up. Or we at least direct our eyes upward. Do we expect the answer to be written on the ceiling? Do we think the heavens might help us remember that forgotten name of an old acquaintance? Are we begging the universe for help? Here's one explanation. Most of us think better when we have fewer distractions. If you stare at something complex, like a page in a dictionary, it's hard to rid your mind of all those visual distractions. If you stare at a blank wall, you have fewer distractions. Now, if you consider that humans lived outdoors throughout most of our history, what would our ancestors usually see when they looked up? The sky. And the sky has few distractions, even when there are clouds. You would certainly see fewer distractions than when looking down at the ground. By eliminating those distractions, we are transferring all our mental faculties from external to internal stimuli. We can think better. Here's another aspect of this to consider. Psychologists have long believed that thinking involves the same brain structures that evolved from pre-existing neural connections for searching for things visually. When you search for a person in a crowd, or search around the house for something you’ve lost, you naturally move your eyes around to help you. This ancient behavior may have also contributed to why we tend to look up when we are thinking. We naturally want to move our eyes, and the best place to look is where there are fewer distractions… the sky.  Mallard Ducklings - Most mallards migrate to the northern US and Canada to breed, but some skip the whole exhausting migration ordeal and decide to breed right here in Missouri. Mallards are the most abundant species of duck in North America. Hen mallards make their nests on the ground (usually near water, but sometimes as far as a mile from water), and lay an average of 7 to 10 eggs. Although the hen and drake stay together before the eggs are laid, the drake usually leaves the hen once she lays the eggs. The hen incubates the eggs for about 28 days before they hatch. The ducklings can walk, feed, and swim as soon as they hatch. After all the eggs hatch, the hen leads the young to water (yep, even walking a mile if necessary), and they never return to the nest. The ducklings stay close to the hen for about two months, until they can fly. By the way, mallards are the ducks that make the classic quack sound. Most other ducks make sounds that are decidedly unquacky (my new made-up word for the day).  Photo Credit: Mallards - Stan C. Smith Missouri is home to the eastern subspecies of the wild turkey (there are a total of five wild turkey subspecies in North America). A few days ago, I looked out the door and saw two hens with twelve poults (young turkeys). They were a good distance away, and the photo only shows three of the poults and the hens. These poults are already about the size of chickens. During the winter, turkeys gather together and roam around through the forest in flocks, searching for acorns and other seeds. Being in large flocks makes it easier to find food and avoid predators. In the spring, the flocks break up, and the toms start gobbling to attract hens to mate with. The hens then create nests on the ground and lay about 10 to 14 eggs (usually laying one egg per day). The eggs hatch after the hen incubates them for about 28 days. After hatching, the poults can walk within hours. They can fly after about two weeks. So, the poults in this photo are almost certainly able to fly. The poults are very vulnerable to predators during the two weeks before they can fly. Once they can fly, they begin roosting in trees, like the adults do. Interestingly, if a predator finds a turkey nest and destroys the eggs, this often triggers the hen to start laying eggs again. Before modern conservation efforts began, wild turkeys almost went extinct in North America. In the 1800s, the entire population dropped to only about 30,000. Today, there are about seven million. The second photo is a mature tom that likes to visit our yard.   Photo credits: Eastern turkeys - Stan C. Smith This white-tailed deer fawn wandered into the fenced-in area of our yard with its mother, then it bedded down to wait for its mother to go in search of food. White-tailed deer fawns have spots to help camouflage them while they are bedded down like this. Unfortunately, people often find them alone and assume they've been abandoned by the mother. Then the people try to "rescue" the fawn, which can result in the fawn's death. During the first few months of a fawn's life, it spends most of its time away from the mother (the doe). This is for a good reason. Fawns can walk and run soon after birth, but they are not fast enough to escape predators that are attracted to the mother (the mother is larger and more active, therefore is more visible to predators). Fawns are much safer bedded down on their own than they are when they try to follow the mother around. They lie very still and only get up and run if a predator comes extremely close. When the fawn senses danger, it will often lay its head low, flatten its ears, and stop breathing, all to reduce its visibility. Remember, the fawn is safer on its own, so the mother visits the fawn only a few times per day, and very briefly. During these visits, the mother allows the fawn to nurse and moves the fawn to a new location. If humans, pets, or predators are around, the mother stays away from the fawn until the danger passes. Does often have twins, or even triplets. When this happens, the doe separates the young. This way, if a predator finds one fawn, it probably won't find the other(s). If a predator flushes a fawn, forcing it to flee, the mother can still find it because the fawn will make bleating sounds once it's safe and is ready to find its mother. So, if you find a fawn bedded down like this, don't assume it is abandoned. The best thing to do is leave it alone.  Photo Credit: White-tailed deer fawn - Stan C. Smith Did you know dogs probably diverged from wolves before being domesticated by humans? The gray wolf (Canis lupus) exists today, and it was long assumed that modern dogs came directly from the gray wolf. However, DNA analysis suggests that modern dogs came from an ancestor (now extinct) of the gray wolf. There is some disagreement on when dogs diverged from wolves. Some evidence suggests it could have happened as long ago as 140,000 years. If so, dogs were definitely already a different species from the gray wolf when humans first began domesticating them. Regardless of whether the dog was already a separate species, this is a fascinating story. One thing we still aren't sure about is, did humans intentionally bring dogs (or wolves) into their camps, or did the dogs (or wolves) come to humans for easier access to food? We may never know whether it was the humans or the dogs that made the first move, but we do know the results significantly changed human history. DNA comparisons show that human domestication of the ancestors of modern dogs took place in eastern Asia, probably in China (note: another study suggests this may have happened in Europe). The dog was the first species humans domesticated (and the only large carnivore ever domesticated). After the relationship between humans and dogs became firmly established, dogs continued following humans, thus spreading across Asia and Europe, and eventually across the Bering Strait into North America and then into South America. What about the archaeological record? Well, there are dig sites, in which the dating is disputed by experts, showing remains of dogs and humans together as long ago as 30,000 years. Then there are numerous uncontested finds from about 14,000 years ago onward. The earliest undisputed find is in Bonn-Oberkassel, Germany—the remains of a dog that was clearly not a local wolf buried beside humans 14,200 years ago. As another example, in Israel there is a burial site with a woman actually holding a puppy. This site is dated at 12,000 years old. Obviously, since that time, dogs have been artificially bred into hundreds of different sizes, shapes, and colors, and they've had a huge influence on human civilization. Below is a gray wolf. Keep in mind, the wild ancestor of modern dogs is possibly an extinct ancestor of the gray wolf, not the gray wolf itself. Another way to say this is: modern dogs and gray wolves have a common ancestor.  With the recent rains we've had here, mushrooms have been popping up everywhere. I spotted these tiny fungus fruiting bodies while walking in the forest. These mushrooms are less than a centimeter across. I discovered that these are called "shaggy scarlet cup." Cool name. They are sometimes also called "pink fringed fairy cup," which I think is an even cooler name. Like all fungus fruiting bodies, these tiny mushrooms grow from the main part of the mushroom, an extensive series of microscopic filaments called hyphae (singular is hypha). The fruiting body grows from the hyphae and produces and disperses spores (the fungus version of seeds). Shaggy scarlet cups are usually found growing on decaying sticks or logs on the ground. Which means the fungus hyphae grow inside the stick or log, extracting nutrients from the decaying plant material. Why a cup shape instead of a typical dome-shaped fruiting body? Numerous species of cup fungi exist. Many of the typical cap-and-stem fungi release spores from the gills on the bottom of the cap, to be carried away by the wind. Cup fungi, on the other hand, produce spores on the surface of the upward-facing cup. Raindrops fall into the cup and splatter the spores out, dispersing them. Just another way to accomplish the same thing.  Photo Credit: Shaggy scarlet cup - Stan C. Smith Let’s say you buy a watermelon at the store, and it tastes so good that you want to extract the seeds and grow your own wonderful watermelons. But it’s a seedless watermelon, so you’re out of luck. Hmm… then how did the watermelon come into existence in the first place? Well, first of all, seedless watermelons actually do have seeds. You’ve seen them, those wimpy little white seed wannabes in the watermelon's flesh. You can just eat those seed wannabes without any problems because they do not have the hard black exterior shell that regular watermelon seeds have. In the flower stage in normal watermelons (with seeds), an egg cell in a female flower gets fertilized by pollen from a male flower, then the fertilized egg grows a fruit. Inside that developing fruit, the seeds are properly fertilized, which causes them to grow that hard shell (called the testa). But in seedless watermelons, the eggs are not properly fertilized. But why not? As with most sexually producing life forms, the egg contains one set of chromosomes and the pollen (or sperm) contains one set of chromosomes. After fertilization, the fertilized egg then has two sets of chromosomes. That’s the way things normally work. However, when growing seedless watermelons, the farmer treats the young watermelon plants with a chemical called colchicine, which causes the eggs in the flowers to develop two sets of chromosomes instead of only one. When those eggs get pollinated, they then have three sets of chromosomes. These can grow into big watermelon fruits, but the seeds in those particular watermelons are not genetically viable—they cannot get properly fertilized and therefore do not grow the hard, black testa. Those fruits are marketed as “seedless” watermelons. So, farmers still must plant regular watermelon seeds, then they treat the young plants with colchicine, and those plants grow "seedless" watermelons. I am of the opinion that food tastes better if you understand how it came to be. So, maybe your next slice of seedless watermelon will taste better than ever! Or, you could just stick with seeded watermelons because the seeds are fun to spit.  I noticed this long ago, and when hotels started putting these products in small, clear bottles, I even made the conclusion that the shampoo was made to look different from the conditioner simply to make it easier for people to grab the right bottle when they have soap in their eyes and they cannot read the ridiculously small print on the tiny bottles. This certainly makes sense to me. But, as is often the case, my conclusion was mostly wrong (although I would still bet plenty of people use this characteristic to choose the right bottle). Conditioner is opaque because it is emulsified. An emulsion is a mixture of two or more liquids that do not normally mix… they are unmixable (I just wanted to use that word). Conditioner is partly water and partly oil. But water and oil do not mix, so chemists have to use an emulsifier to make them mix. When the emulsifier makes the water and oil mix, the mixture becomes opaque. Now, shampoos on the other hand are partly water and partly a surfactant. A surfactant is something that reduces the surface tension of the liquid in which it is dissolved. In the case of shampoo, the surfactant acts as a detergent and a foaming agent (we all love our shampoo to foam up nicely, right?). Well, there is very little oil in shampoo, so there isn’t a need for an emulsifier, and therefore the shampoo remains transparent. But what about those shampoos that are opaque? Yes, there are some, and it is usually because they have much higher oil content (or they are shampoo and conditioner combined). Okay, seeing as how you are probably mesmerized by the exciting topic of shampoo, let’s look at a related question: why do we have to use shampoo before we use the conditioner? What if I’m feeling rebellious and want to reverse the order? Well, remember that shampoo has a surfactant that reduces surface tension, so the shampoo does not cling to your hair. Shampoo washes out completely, and therefore does not leave any conditioning coating to moisturize the hair. Conditioner clings to hair, because conditioners have positively charged ingredients that tend to adhere to hair, which is naturally negatively charged. This is why we use conditioner last—to leave a protective coating on the hair. So, now you can wash your hair in a very knowledgeable way. And if you can’t read the bottle because you don’t wear your glasses in the shower, use the clear stuff first, then the opaque stuff.  |
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