The 17 Year Itch

That sound you hear isn’t the Six Million Dollar Man using his bionic powers. It’s cicadas by the billions. Every year, at least a few cicadas emerge during late spring and serenade us with their mating call. Chunky and scary looking, these insects are totally harmless but to me at least, just hearing them makes it feel a little hotter and muggier. 

This year is a little louder than most. Brood X, the largest brood of periodical cicadas, is emerging after 17 years underground in the larval stage. They’ve been tapping into tree roots during that time and now that they’ve reached adulthood they’re ready to go out in a blaze of noisy glory. They'll mate soon, lay their eggs in the tree tops, and die. When the eggs hatch, the larval cicadas will drop from the tree, burrow into the ground, and start the timer on another 17 years.

Expect it to be a little louder than usual in the Northeast
(From "This Is Spinal Tap")

All those bugs means not just a lot of noise, but also a lot of food for just about everything. The reason cicadas emerge by the billions is to overwhelm their predators’ stomachs. The strategy is that lots of cicadas will get eaten, but based on sheer numbers, many will survive to continue the life cycle for another 17 years. 

Periodical cicada (NPS)

Speaking of 17 years, why such an odd number? It’s another evolutionary strategy. What other critter can you think of with a 17 year life cycle? It reduces the risk of broods emerging during a population boom for a predator species. As a double failsafe, broods have stragglers that emerge either before or after the 17 year period.  Most are within a 13 to 21 year period. It gives the brood a better chance of survival in the event that the 17th year is a boom year for predators. 

Molting cicada (Baltimore Sun)

I've never seen a cicada coming out of its shell. Like all insects, they have a hard exoskelton, and immediately after emerging they molt. From what I'm being told, people all over are finding a lot of those shells on tree trunks and other surfaces. I haven't seen any yet this year, but I haven't been able to get outside much other than a birding expedition to New Jersey which you can read about later. This week's information comes from the University of Connecticut. 

Hard Working Animals

Police dogs, draft horses, barn cats, and lab rats are all animals that could be considered to work a full time job. In a salute to Labor Day, here are a few wild animals that work just as hard as humans and domestic animals.

Earthworms are working hard to keep your garden healthy. Often overlooked because they remain unseen, these slimy little guys are tunneling all day, allowing air and water to move around the soil. They cycle nutrients by eating decaying plant matter, creating fertilizer that living plants can use. 

Earthworm (Christian Science Monitor)

Mound building termites built mud homes that can reach heights of 17 feet and displace a quarter ton of soil. It can take years to build, and a single heavy rainstorm can damage or destroy it. Worker termites are always on the ready to make repairs as needed. Additionally, they also farm a fungus as a digestive aid. The fungus breaks down partially digested cellulose from the wood and grass the termites had eaten. After the fungus does its thing, the termites re-ingest what the fungus broke down.

Termite mound (Journal of Experimental Biology)

Beavers are the best known engineers in the animal world. They build water tight dams out of sticks and mud. Ponds form behind the dam, and while the beavers selfishly build dams and create ponds for themselves, the important wetland habitat benefits many other species as well. Even humans benefit, as the wetlands filter water and serve as flood control.

Beaver preening

Beaver dam

While you're enjoying a long weekend, just remember the critters that work hard 365 days a year just to survive. This week's information comes from National Geographic for worms and termites.

Species of the Month

We're still in Old Man Winter's icy grip for at least another month, so it's the perfect time to feature another critter that thrives in cold, snowy weather. This month we'll take a look at the elusive Canada lynx.

Canada lynx slinking among the vine maples

Scientific name: Lynx canadensis

Kingdom: Animalia (animals)

Class: Mammalia (mammals)

Order: Carnivora (carnivores)

Range: Circumpolar- Canada, northern US 

Habitat: Forest and tundra

Lifespan: Up to 14.5 years

Diet: Snowshoe hares, rodents, birds, fish, carrion

Predators: None known though bears and wolves may prey on kittens

Conservation Status: Listed as threatened under the US Endangered Species Act and endangered by the state of Michigan

The giant feet are visible in this shot (USFWS)

Other Information: The lynx is known for its intricate relationship with the snowshoe hare. The lynx population fluctuates in response to that of the snowshoe hare, with the lynx lagging by about a year in a nine year cycle of boom and crash. The lynx may as well be known as a snowshoe bobcat, as they are similar in appearance. The lynx has large feet that work as snowshoes, allowing it to hunt in the deepest snow. Another difference between the cats is the longer tufts of ear hair on the lynx. Litters are commonly two or three kittens, born April to June. They stay with the mother until the following mating season, almost a year later. Lynxes are solitary creatures, and are mainly nocturnal hunters. While smaller animals are their main prey, they will take a sick or injured deer if the opportunity presents itself.

This shot offers a better view of the ear hair (USFS)

This week's information comes from the University of Michigan's Animal Diversity Web.

I Wanna Rock!

Let’s explore a mystery of geology this week. I recently visited a nearby park known for its unusual rocks. Ringing Rocks features a boulder field of musically inclined rocks that ring like bells when struck with a hammer, rather than clunking like a rock.

Approaching the sonorous stones from the woods

The boulder field is surrounded by a hardwood forest. Within the forest are a few scattered boulders. None of the forest boulders were music to my ears, but supposedly the ones in the boulder field that clank are still ringing, just at a pitch too low for humans to detect. Somehow, the interaction with other boulders is what makes the ringing sound.

Boulder field of musical rocks

The rock type is olivine diabase, an iron-rich volcanic material. Being made from iron probably accounts for the metallic sound. The diabase broke into boulders thanks to Pennsylvania’s wonderful cycle of freezing and thawing. Water finds its way into a crack in the rock, expands when it freezes, and over time causes the rock to fracture.  

Me, demonstrating my musical prowess

The boulders in the field are available for you to gleefully tap with you hammer. On the one hand, this is great because anyone and everyone is free to experience the geological oddity. On the other hand, the boulders show noticeable pock marks from years of hammering. Eventually, the boulders will break. Will they lose their ability to carry a tune when that day comes? No one knows for sure.

This week's information comes from Unmuseum and S. S. McCray (Petrogenesis of the Coffman Hill diabase sheet, Easton Pennsylvania (unpublished B.S. thesis)).

This is a Crappy Subject

Now for the dirtier side of nature. Pretty much every living thing on this planet exists to be someone else’s meal. If you’re unlucky enough to become lunch, the next step is you become poop. No one likes to talk about it, look at it, or smell it. Even though it’s gross, it’s an essential element of the environment for a couple of reasons.

Raccoon scat

The most important function of poop, or scat as we call it in the science world, is a key role in the nutrient cycle. Every living thing needs an assortment of minerals in order to function properly. Minerals are absorbed from the soil by plants, then absorbed by herbivores that eat those plants, then absorbed by various levels of carnivores up through the food chain. Some minerals are present in the ground in rocks; others are returned to the soil through decaying organic matter (plant or animal) or through scat.

Nutrient cycle (from Exploring Nature.org)

Another important impact scat has on the environment is negative, and it goes beyond getting on your shoe. Nitrates and phosphates are common in scat, and also happen to be active ingredients in fertilizer. Excessive nitrates and phosphates in storm runoff causes high nutrient levels in lakes, streams, and even the ocean. Those high levels can cause an overgrowth of algae. Too much algae, even though it produces oxygen, can cause dead zones of little to no oxygen when the algae dies and decomposers feasting on it suck all the oxygen out of the water.

Algae bloom (Michigan Radio)

A third way scat is important is as a research tool. It allows people like myself who rarely observe animals in the wild to see what animals have been down the trail before. DNA samples can be pulled from scat, and population biologists can estimate population by counting turds. Ecologists can study an animal’s dietary habits from looking at scat.

The coyote that dropped this deuce ate a bird

Deer scat

Now that you’ve seen the usefulness of animal scats, maybe you will look at it in a whole new light on your next foray into the woods. Like anything else in nature (except maybe spiders), if you can overcome your aversion, you can learn to appreciate it.

Species of the Month

September’s Species of the Month is our first fish to be featured. Pink salmon are returning to their birth rivers along the Pacific coast. They are the smallest and most abundant of the five Pacific salmon species found in North America. When you buy canned salmon, it is most likely pink. Besides feeding us, they also support entire ecosystems.

Scientific name: Oncorhynchus gorbuscha

Kingdom: Animalia (animals)

Class: Teleostei (ray-finned fishes)

Order: Salmoniformes (salmons)

Range: Northern Pacific Ocean from East Asia to California and upstream

Habitat: Rivers and ocean

Lifespan: Two years typically, some may live three years

Diet: Insects and plankton (juvenile) and fish (adult)  

Predators: Bears, killer whales, osprey, eagles, sea lions, seals

Conservation Status: No special conservation status

Other Information: Pink salmon is an anadromous fish, meaning it is born in freshwater then moves to a saltwater phase before returning to the stream it hatched in to spawn. These fish typically spawn close to saltwater, sometimes even in the saltwater. After hatching, the salmon fry immediately swim downstream to the ocean. Pinks are also known as humpies, named for the large hump spawning males grow on their backs. The two-year life cycle of the pinks is the only completely predictable salmon life cycle. Other species may spend 2-5 years at sea, depending on the species and the individual. Pinks, like other salmon, are an important food source for bears fattening up for winter. They are also incredible swimmers, amazingly agile in just a few inches of water. I walked in the river with them and despite their fins being above the surface and my longer stride, I was unable to keep pace with them. Due to low river levels followed by flooding that affected the 2015 spawners, the 2017 pink salmon run is forecasted to be a fraction of the previous run.

Info this week is from USGS  and Alaska Department of Fish and Game.

Spawning female pink salmon, Mashel River 2015

Spawning male pink salmon, Mashel River 2015

Cosmic Ballet, Part 2

Despite dire warnings not to travel to Oregon for the solar eclipse, I went any way. Traffic was not as bad as predicted. My gamble that everyone going to Oregon would have left over the weekend paid off. My gamble that homeward-bound traffic would be going the opposite direction of where I was headed paid off. I even managed to get some pictures for those of you who weren't lucky enough to witness totality, which was a first for me.

Before totality, small chunk of sun missing from top right

The eclipse caused these funky curved shadows

Using your hands to make a pinhole viewer

Totality! The black circle is the moon, the white ring is the sun's corona

The sky was dark enough that some stars were visible. I think this is Venus.

The eclipse got underway just after 9 AM Pacific time, immediately preceded by a flock of birds flying overhead away from the sun. Was that related to the eclipse? I don't know. I don't recall seeing any birds until after the eclipse was over. It took a while to notice any changes in lighting, but as totality got closer it was like someone turning a dimmer switch until it got dark. At that point, the eclipse glasses came off, the pop of some fireworks, and the crowd at the nearby football field let out a cheer. It was oddly quiet and oddly dark for about a minute until there was a flash of light where the top of the sun came out from behind the moon and the dimmer switch turned the other way and daylight returned.
The next total solar eclipse to hit the US is in April 2024. At that time, I hope to be in the field studying how animals react to an eclipse. Not much is known because they are such an infrequent event. Many animals run on a solar (day-night) cycle and scientists like myself wonder what they do when night suddenly happens during the day for a brief period.
Stay tuned for more stories from the road following Nature Minute's great American road trip!

The Cosmic Ballet Continues

This Monday the United States will witness the rare and majestic total solar eclipse. Not all areas will see a total eclipse, but all of North America will see at least some of the sun disappear. While not a rare event, it is unusual for a total solar eclipse to cover such a large populated area. It seems like usually they happen only over the remotest part of the Pacific Ocean or exclusively at the South Pole. This eclipse will the first total solar eclipse to hit the US since 1979. That might not be too terribly long ago, but think about this: in 1979 there were still people alive who could remember the last time the Chicago Cubs won the World Series (1908) or fought in the war against Spain in 1898.

What is a solar eclipse? When the moon passes between the sun and Earth and casts a shadow on us, that’s a solar eclipse. They can only happen during a new moon, which is when the sun’s rays hit fully on the “dark side” of the moon, so it’s the only time you’ll ever see a new moon. New moons happen every 29 days, just like a full moon, but we don’t have a solar eclipse every month because of how the sun, moon, and Earth dance with each other.

Geometry of a solar eclipse- not to scale (from Nustem)

You’ll notice the sun is a lot higher in the sky now than it was in January. Because Earth is tipped about 23̊ as were orbit the sun while spinning in our tipped circle (which also wobbles) the sun appears to ride a squashed and stretched figure 8 across the sky called the elliptical. The moon does the same, but their ellipticals don’t always match. When they do, you get an eclipse.

Distance is also important. Neither Earth’s orbit nor the moon’s is circular; both are slightly elongated (an ellipse, hence the term elliptical) so sometimes the moon close enough to block out the sun during an eclipse and sometimes it fits inside the sun like a ring. This is called an annular eclipse. Like during a total eclipse, only a narrow band will see the annular eclipse, while everyone else gets to see a partial eclipse or nothing at all.

Annular eclipse (from Universe Today)

Partial eclipse (from Huffington Post)

Always practice safe eclipse viewing! Follow these tips from NASA. Never look directly at the sun, even during an eclipse. The only exception is during totality, and that is ONLY if you have totality where you are at, and it only lasts about a minute and a half. Use eclipse glasses- if you put them on and try to see anything but the sun, you should only see blackness. Sunglasses will not do the job. Never look at the sun through binoculars or a telescope, unless you have a solar filter. If your solar filter screws on to the eyepiece, it is junk- throw it away! If you don’t have any safe viewing equipment, make a pinhole viewer by poking a hole through a piece of cardboard and let the sun shine through. During the partial phase, you will see a spot of sunlight missing a chunk in the middle of the cardboard’s shadow.

I will be in Salem, Oregon for the eclipse, immediately preceding a very special Nature Minute road trip. Sorry, no live-blogging. I can’t blog while driving, and besides, there’s no wifi in the wilderness. Check back in September or follow along on Facebook for pictures and tales from the road.

This week's credits: Nustem, Huffington Post, Universe Today, and NASA  

Keep Bugging Me

Plants are important to life on Earth. They put oxygen in the atmosphere as a byproduct of photosynthesis. Everyone has to eat, and plants for the base of the food chain. Just as important, and either overlooked or swatted aside, are insects. I consider insects to be the second lowest man on the food chain totem pole as they are super abundant and are the prey of choice for many of the first order predators. In addition, many of them support plant life by serving as pollinators. Others are beneficial because they eat other insects that are crop pests. 

Hoverfly working hard to pollinate

Fritillary butterfly pollinating

I never saw this little pollinator before today

Insect larvae, such as fly maggots or aquatic larva such as mayfly and caddisfly larva, play an important role in the nutrient cycle, breaking down dead plant and animal matter and cycling it into the soil for plants or cycle it even higher in the food chain by being eaten by something bigger than a plant.

Aquatic insect larvae are important indicators of ecosystem health. The absence or presence of certain bugs in the water can tell researchers a lot about water quality. Data collected from stream bug surveys can be used in habitat restoration and conservation projects. 

Caddisfly larvae, an important salmon food

Water strider- fish food

Insects are a great teaching tool. When my daughter was little, insects were her introduction to nature. They are lightweight, portable, easy to catch, and almost everywhere so there was always an opportunity to teach her something new. 

A ladybug, one of my daughter's favorites when she was little

Many of the birds we enjoy seeing or hearing eat insects. Salmon are commercially important fish species that depend on insects and/or insect larva in their early stages of life. The flowers in your garden, not to mention many crops, are there because of insects. Next time you eat an apple, smell a rose, or hear your favorite bird hug a bug! 

Unknown tiny insect that landed on my shirt one day

Bee on its 10 minute break

Praying mantis or preying mantis?

Porcupine Love

I was driving past Northwest Trek, a wildlife park which also does extensive conservation work, and I suddenly wondered how on Earth porcupines mate. Their quills are barbed so as to injure any critter that tries to attack it, but doesn’t that seem like it would hinder mating?

So I did a little digging, and in addition to quills being a roadblock to mating, females are frigid for 364.5 days a year (365.5 in a leap year). However, when she is ready to go for 8-12 hours each year, she will signal the males with secretions, which is how it typically works in the animal world.

When it is time, the successful male may have to ward off challengers. To set the mood, the female curls her tail over her back and relaxes her skin, which flattens the quills and reduces risk of impalement. 

They will do this several times until the female tires of her mate, who will go in search of more females having that time of the year. The female will have a seven month gestation period, followed by four months of lactation. Then after a month, it’s time to start over again. In case you’re wondering, when baby porcupines are born their hair is soft and hasn’t hardened into quills yet. Childbirth is painful enough already.

Here's a Youtube video of how it happens.

This week’s facts courtesy of Live Science

Solar-powered Cycles

You probably noticed by now that the days are getting shorter and the air is a little chillier. Fall has fallen! The sun gives life to everything on Earth through heat and energy for plant photosynthesis. It also triggers changes in life cycles, some of which are evident to almost everyone right now.

The most obvious cycle that is affected by the sun is the current situation with our tree leaves changing colors and falling off. Because Earth’s axis is tilted 23 degrees, we experience seasonal variances in the amount of sunlight we get. As we move through fall and into winter, the sun sinks lower in the sky and light that hits us is less direct.

Nature loves efficiency, and trees lose their leaves this time of year because with decreasing sunlight, they would expend more energy performing photosynthesis (turning sunlight, water, and carbon dioxide into energy) than they would get from it. Chlorophyll, the active photosynthesizing pigment, dries up and the cells in the leaf stem die, weakening it to the point that it falls off the tree. Until spring arrives, trees and other plants live off of starches stored in their roots. That starch is the byproduct of photosynthesis.

Other seasonal cycles are the leafing out of trees, hibernation, and mating seasons. Some cycles run by the sun can be daily, not just seasonal. Dandelions and other flowers close their petals at night. Daily sleep cycles are also affected by sunlight. Animals don’t use an alarm clock, but they do have an internal clock.

Bigleaf maple

Even shrubs change colors

The Hidden Community (Part 2 of 2)

Have a look at your lawn. Under the immaculate grass is an invisible world, the soil community. Your yard, like millions of others, is home to an amazing assortment of critters. Most of them you will never see. They range in size from microscopic bacteria and fungi to macroscopic moles and gophers. Each plays its own important role in maintaining ecological balance.

Many soil organisms play a key role in several mineral cycles, including the carbon cycle and nitrogen cycle. I don’t want to say any one organism is more important than any other because they are all cogs on the same great wheel of life, but if I had to I would assign that title to nitrogen-fixing bacteria. These little guys have a symbiotic relationship with plants that allows plants to absorb nitrogen, which is critical to their growth and development. And we all know plants are critical for everything else that’s alive.

Decomposers such as fungi and bacteria consume dead plant and animal material. In doing so, they return carbon and other nutrients that had been locked up in dead material to the soil where it is absorbed by plants and becomes life again.

Below is a chart of a simplified soil food web.

Other soil organisms like earthworms and moles aerate the soil with their tunnels. The tunnels allow for easier movement by air and water, benefiting plants and animals alike. Moles might be ruining your perfect lawn by making look not so nice, but they are actually making it healthier by doing some free landscape work.

Again, information is courtesy of my soil science textbook Soil Science and Management by Edward Plaster.

Did you know? Mushrooms are actually the fruiting bodies of fungi. The “body” of a fungus is actually a collection of long, thread-like cells that can be very compact or quite large. (Thanks to University of California Museum of Paleontology, http://www.ucmp.berkeley.edu/fungi/fungimm.html)

The largest organism in the world is in fact a fungus. It lives in Oregon and is estimated at 1900 to 8650 years old. It covers 2385 acres in Malheur National Forest of eastern Oregon and is known as the Humongous Fungus. (US Forest Service, http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev3_033146.pdf)