Today is Endangered Species Day! It’s sad that we have to have such a day as this, but hopefully it can spread awareness and maybe our endangered species today won’t be so endangered tomorrow. What’s your favorite endangered species? Do you know how you can help?
A Clemson University student conducted research that showed that some drivers purposely hit turtles they see trying to cross the road. Lend a hand (but watch your fingers) and help turtles safely cross the road!
This spring and summer people in the Northeastern United States are in for a treat, or a scare, depending on how you look at it. We’re being invaded. Not millions, but billions, have been lurking under our very feet, waiting. They haven’t been seen in 17 years but now it’s time. They’re coming out in force. But, they’re not coming to get you.
Cicadas are an order of insect that contains around 2,500 herbivorous species. Some people might think they’re a bit freaky looking as their eyes are prominent on their heads and can be red or black, and these insects can be a good size, ranging from 2 to 5 cm (0.8 to 2 ins). However, they’re completely harmless to humans.
What is interesting about these creatures is that they spend the majority of their lives underground as nymphs. They survive on plant root juice while the adults drink tree sap. The group that has been and will be seen here in the northeast coast have been lurking underground for 17 years, having been born in 1996 when their parents emerged, bred, and died. They too will rise up to become adults, breed, and perish within just a short time, leaving behind eggs on trees that will develop and then allow the larva to drop to the ground, where they will stay for another 17 years.
Not all cicadas live underground for 17 years. These insects can be grouped into three different categories. There are the annual species with yearly lifecycles. An example would be the swamp cicadas (Tibicen tibicen). Then there are the periodical species such as the ones merging now, which can pop up between 2 and 17 years depending on the species. Those 17-year variety are considered the longest living insect, even if their adult lives are short-lived. In the U.S. these consist of the Magicicada species. And then there is the proto-periodical group. These insects may emerge every year but there are particular years that have particularly heavy populations.
The ones that will be sweeping the United States from Georgia all the way to New England are called Brood II. Brood I emerged elsewhere last year while Brood III will emerge in another area next year. There are believed to be 15 different broods in the U.S. Twelve of these broods have 17-year life cycles while only three have 13-year cycles. Interestingly, each brood may consist of more than one species and there are only seven known U.S. periodical species. The widest ranging brood of 17-year species, Brood X, will cover 15 states but will not appear until 2021. They will also appear in my state, New York, just like Brood II. Actually, Brood VII, which will emerge in 2018, is expected only to appear in New York. Yet, there are no 13-year broods in New York.
Cicadas are known for their mating song which the males make in an attempt to attract females. They use a piece of their exoskeleton, called the tymbal, that has evolved to make a loud noise when it is contracted and released. Since this region of the male is also hollow, it aids in amplifying the sound. Among the loudest of all insects, some species produce such a loud volume that they could cause ear drum damage to humans if they were to sing right outside of the ear. Other species “sing” at such a high pitch that humans can’t actually hear it at all.
The tymbal isn’t just used for making sound, but also detecting it. Females have these structures as well and it aids them in picking up the vibrations of others.
Some people enjoy the sound, while I’m sure it drives many others crazy. It’s louder than the frogs and crickets many are used to. They may not be your cup of tea, but perhaps they are. Some cultures actually eat cicadas, with the females being prized for their more plump bodies. Do you know what they say about insect meat? Lots of protein!
If you have found interest in our blooming brood more information can be found. The Magicicada Mapping Project, which is sponsored by the National Geographic Society, is currently creating up-to-date maps of the cicada emergence and documenting events as they occur! I once had a cicada exoskeleton and thought it was pretty cool. I’m hoping to get an up close and personal introduction to a living member of the species this year.
Lately I’ve been working a temporary evening job after my regular day job (makes for a long day). It’s not hard work, just grading standardized test. This particular project is reading. The kids read passages about various topics and then construct a short written response answering a question. Two of these questions are about flying squirrels.
I found it interestingly coincidental that one of my previous instructors just caught two of these little creatures in one of his field courses. What I find most interesting about these animals is their evolutionary adaptation, not to fly, but to glide. You see, their name is deceiving. The only mammals that actually fly are bats. Still, there are various animals that are calling “flying” yet actually don’t. All of their adaptations are similar and are fascinating.
There are 44 species of flying squirrels. Don’t worry, I’m not going to list all of them, but they can be broken down into 15 genera, 13 of which are in various parts of Asia, 1 can be found from Finland to Japan, and 1 is in North America. I’m willing to bet these little creatures are flying around my backyard at night, but I’ve never seen one.
Africa’s scaly-tailed squirrels, of which there are seven species, six of which glide, are not true squirrels but thanks to convergent evolution look and behave much like flying squirrels.
A similar genus is Petarus which are flying phalangers or wrist-winged gliders. They are arboreal marsupials. The six species that make up this group are the squirrel glider, mahogany glider, northern glider, yellow-bellied glider, Biak glider, and probably the most well known, the sugar glider. These gliders can be found in Australia, Tasmania, and New Guinea. (A note on the mahogany glider is that these animals are so rare that after they were first discovered in 1883, they were not found again until 1989. It is a sad fact that this habitat was then cleared only a month after their rediscovery, for the creation of plantations, and another population wasn’t located until 1991).
A closely related animal is the Petauroides volans which is also known as the greater glider. Found in Australia, a key difference between this animal and the flying phalangers is that the patagium only extends to the elbow.
The feathertail glider (Acrobates pygmaeus) is the smallest of the gliders and is also known as the flying mouse. Australia has a lot of flying mammals, apparently.
Another “flying” mammal is the colugo, otherwise known as the flying lemur (though they are not true lemurs). There are only two of these species, both found in Southeast Asia: the Philippine flying lemur (Cynocephalus volans) and the Sunda flying lemur (Galeopterus variegates).
None of these mammals are closely related. However, with a marvelous stroke of evolution, their adaptations are so similar that I decided to group them together to explain how they glide. Glide, not fly.
All of these species are capable of gliding through the air due a membrane of skin that extends between their limbs called the patagium. In flying squirrels and wrist-winded gliders this membrane is attached on the left and right side of the body and stretches out to the ankle of fore and rear paws similar to the wing of a bat. In the colugo this membrane also goes from the both rear feet to the tail and in between their fingers, allowing them the maximum amount of gliding capacity of the species.
Other “flying” animals have similar evolutionary adaptations.
Flying fish, a group of 64 species, have long wing-like fins. They can propel themselves out of the water with their strong tails and then use these fins to glide above the water. The average distance for this fish is about 50 meters (160 feet), but one study noted a fish gliding for 45 seconds while another observed another fish gliding 400 meters (1, 300 feet). This trait was developed as a means of escaping predators
Some members of the family Ommastrephidaei, a family of squid, have been known to glide above the water to escape predators as well, earning them the name of flying squid. These squid can launch themselves out of the water to escape predators. Instead of using their tails, since they don’t have one, they shoot water out, propelling themselves up out of the water and into the air. They have fins of varying sizes toward the back of their mantels that aid the squid in stabilizing themselves and catching air above the water.
There are two families of gliding frogs, Rhacophoridae and Hylidae flying frogs. Some of these frogs can glide fair distances while others have evolved more of a parachuting method of free-fall. A study from 1990 by S.B. Emerson showed “enlarged hands and feet, full webbing between all fingers and toes, lateral skin flaps on the arms and legs, and reduced weight per snout-vent length”, at least in the Rhacophoridae families.
There are several species of gliding reptiles, the family of Draco lizards probably being the most familiar. Unlike the gliding mammals, the patagium of the Dracos does not connect to their limbs but is supported by elongated ribs instead. These adaptations kind of make them look like mini dragons. Another gliding reptile is the neon blue-tailed tree lizard (Holaspis guentheri). These animals do not have a flap of skin to help them glide but have a fairly flat body and tail and such a light bone structure that they have been described as “falling like a leaf.” There are four families of “flying” geckos that have flatter bodies and many have wider “webbed” feet. There are even five species of gliding snakes with the most capable being the paradise tree snake which glides by stretching out its body sideways and opening its ribs so the belly is concave, and by making lateral slithering movements.
There are several differences that make these animals glide instead of fly. Unlike bats, most birds, and many insects, these gliding animals cannot flap their “wings”. Since they cannot do this they are not capable of creating thrust to lift themselves up. Instead, these animals must launch themselves from one height and glide to a lower height, or in the case of the marine lift, us another method to create temporary thrust. They cannot increase in height unless there is a great deal of wind to create upward thrust for them and they have limited air time that is dependent on wind velocity and lift. The mammals and some of the fish have a significant amount of control, however, by manipulating their limps and tail. The mammals can tighten or loosen their patagium for direction as well as form their skin to create a slowing parachute affect for landings.
So, next time you see something soaring through the air, pause and consider. It is a bird? Is it a plane? No, maybe it’s a squirrel!
Last week we discussed all the variations in bird nests, so it only makes sense we discuss what goes IN those nests this week… Eggs! Now, I’ve talked about them before, but let’s go into more detail. Eggs are just as unique as the species themselves, sometimes as unique as the individual. Bird eggs, of course, usually contain a single bird offspring. Consider it a form of bird pregnancy, except outside the body.
Bird eggs have evolved in a way to keep in moisture so that they do not have to be laid in water, such as amphibian eggs which will dry up otherwise. They are comprised of several parts: the yolk, which is where much the nutrients such as fats, cholesterol, and proten is stored along with the the membranes that keep it contained; the germinal disc found on the yolk and containing the DNA nucleus of the female ova (little side note: if the egg is fertile this disc is called a blastoderm but if it is not, it is called a blastodisc); the chalaza are two spiral bands of tissue that suspend the yolk in the center of the albumen; the albumen, which is the clear/white part of an egg containing water and more protein, also nutrients for the developing chick; a bit of air space; and the hard surface of the egg, made of made of calcium carbonate.
It’s the calcium carbonate that usually makes many eggs white. For some eggs this is fine, but others need camouflage to hide from predators, especially if they’re on the ground. Many eggs are spotted while other eggs, such as those of the American robin (Turdus migratorius), can be quite bright. In this case they’re quite a noticeable blue.
The classic bird egg shape is oval or more of a tear-drop, such as those from chickens, but there are others. The loon, for example, has a more elliptical shaped egg while many owls have eggs that are more spherical.
The largest bird egg belonged to the elephant bird (Aepyornis maximus) and those eggs were 34 cm (13.5 ins) long. Elephant birds, flightless birds of Madagascar, are now extinct and have been since the 17th or 18th century. The largest egg from living bird species belongs to the North African ostrich (Struthio camelus), which can get up to 20.5 cm (8 ins) long.
The smallest bird egg is from the living vervain hummingbird of Jamaica (Mellisuga minima) , which reaches a whopping size of 1 cm (0.39 in).
Interestingly, relative to body size, the elephant bird and ostrich eggs really aren’t as impressive as they might sound. Ostrich eggs are actually one of the smallest when you consider the size of the bird while it’s the hummingbird that actually has one of the largest. However, it’s New Zealand’s kiwi that has the largest egg compared to the body, being up to 20% of the female’s weight.
Eggs are cool, but they have some vulnerabilities. They aren’t rocks; that shell can be crushed or cracked open, so the main defense is usually the parents and sometimes camouflage. However, they can also be damaged without even being touched. Last year I talked about DDT and the destruction it caused to the bird population. Pesticides, herbicides, and other environmental toxins can harm the developing fetus or weaken the egg itself. Clean environmental mean happy eggs.
This is also the TWO year anniversery of Where The Wolves Once Roamed! I thank you all for reading and as always, if you have any comments, questions, or post suggestions, let me know. Here’s to another year!