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.

Cave Life

This week is Cave Week, so to celebrate we're going spelunking to see what critters we can find. In addition to all sorts of whimsical formations, caves host a surprising amount of life. There are trogolobites, which live full time in caves; trogolophiles, which live in a cave but can also survive outside; and trogoloxenes, the part time cave denizens. You can encounter insects, fish, birds, mammals, plants, fungi, and others. Because there is very little natural light, many of these species are adapted to live in darkness; some don't even have eyes.

Whimsical cave formations

The first cave critter that comes to mind is a bat. Many bats roost in caves because they are cool and dark during the day, making it easier to sleep. Caves make a great place to hibernate over the winter. A constant temperature that is above freezing is an obvious plus, but it's cool enough to trigger the hibernation process. Other cave mammals include bears and jumping mice.

To the bat cave! (National Science Foundation)

Plants are a rare find in  caves because they need sunlight for photosynthesis. I saw ferns growing in a cave under a ceiling hole that opened to the surface. Much more common are fungi, which thrive in dark, damp conditions. Most important among them is Pseudogymnoascus destructans, which causes White Nose Syndrome in bats. It is devastating bat colonies across the US and Canada, and enjoys the cool temperatures while the bats hibernate.

White Nose Syndrome affecting these bats (NPS)

Cave fish are interesting little critters. Nearly all lack eyes and skin pigment. With no light to see by, there is no need to camouflage or stand out, so they are likely to be white or light colored. Unable to see their food, they find it by sensing movement in the water. What exactly do they eat? Since plants, the base of the food chain can't really live in a cave, anything in there either needs to go outside for good or eat whatever gets brought in. Cave fish eat detritus that washes in during rain events. Other critters get by on dung, the leaving of larger animals that way out.

Blind cave fish (NPS, Rick Olsen)

Cave Week runs through this weekend. Find a cave near you and check it out. Spelunk safely. Use the buddy system, carry at least three light sources, and make sure someone knows where you are going. Don't disturb any wildlife and make sure clothing and equipment are thoroughly cleaned before entering another cave. This helps prevent the spread of White Nose Syndrome.
This week's information comes from the National Park Service and National Geographic.

Species of the Month

December’s Species of the Month, like last December’s, is a living symbol of Christmas. Holly, with its green leaves and red berries, has become of a jolly symbol of the most wonderful time of the year. The Species of the Month is American holly, native to the eastern US and lower Midwest.

Scientific name: Ilex opaca

Kingdom: Plantae (plants)

Class:   Magnoliopsida (dicots)

Order: Celastrales (flowering trees)

Range: New York and southern New England south to the Gulf Coast, west to Texas

Habitat: Well-drained forests, coastal areas

Lifespan: About 100 years

Diet: Sunlight and water

Predators: Insects including southern red mite, holly leafminer, and holly midge; fungal diseases; birds may eat the berries and herbivores may browse the leaves.

Conservation Status: No federal protection; listed as Exploitably Vulnerable in New York and Threatened in Pennsylvania.

Winter holly at Gateway National Recreation Area (NPS Facebook photo)

Other Information: American holly is used as an ornamental planting. Its branches are used in Christmas wreaths. The Pilgrims named American holly, based on its similar looks to their familiar English holly, which had been established as a Christmas decoration for some time. A slow grower, it is typically an understory plant, although some have been known to reach 100 feet tall. Because it is usually found in the understory, it is rarely the dominant plant in a forest. However, an excellent example of a holly forest can be found at Sandy Hook, New Jersey. Both male and female hollies flower, but only the females produce berries. Birds are an important method of seed dispersal. Holly’s wood is among the whitest woods on the market. It is not very strong so its commercial use is limited. Small green flowers are hardly noticeable.

This week's holly information comes from the US Forest Service. 

My 2016 Christmas card, featuring holly in my yard

Coastal holly in North Carolina (NPS)

More holly in New Jersey (NPS Facebook photo)

I'm Lichen This Blog

This week Nature Minute will take a look at another unsung hero of ecology, the oft-overlooked lichen. There are many different lichens and they can be found just about everywhere. You’ve probably seen lichens. Maybe a greenish-gray circular spot on a rock, or on the bark of a tree (mistakenly referred to as moss).

Last year, I did a two-part series on the importance of soil. Lichen is just as important to life, if not more so, because lichen will frequently colonize bare rock and secrete chemicals that break down the rock. Thus begins the making a toehold for more advanced plant life to follow. This succession is the beginning of soil formation.

Notice above I said “many different lichens” and not “many species of lichens”. That was intentional, because while a lichen is a living organism, it is not a single species, but a symbiotic odd couple relationship between a fungus and an alga (singular of algae). Some lichens will have a green alga, some will have a blue-green alga, and still others will have both.

How does this crazy living arrangement work? The fungus provides the lichen’s structure. The algae provides the food through photosynthesis. In many cases, the fungus and the alga are perfectly capable of living on their own. Yet for some reason, sometimes they chose to live as roommates in a lichen apartment. There must be an evolutionary advantage.

Perhaps it is the chemicals produced by lichens. Very few insects munch on them, although tundra animals will. They are also very hardy, able to withstand complete desiccation. I don’t know of any fungi or algae that can do that on their own.

Because of the separate living components of lichen, it is impossible to trace the evolution of lichens like we can trace other organisms through DNA and the fossil record. So scientists can’t say how this unlikely partnership formed, although they can tell us how new lichens are made. Because it’s different species living together, you can’t just have a male lichen mate with a female lichen. The fungus and alga can reproduce individually, but their offspring won’t necessarily form a new lichen. However, the lichen can form a soredia, a group of the alga’s wrapped up in filaments provided by the fungus. This little ball of oddities rolls off and starts a new lichen. Another way for lichens to “reproduce” is for a piece of lichen to flake off and drift to a new home.

I hope you enjoyed this week’s fascinating look at one of nature’s weirdest partnerships. Now that you know how weird those mundane little blotches are, maybe you’ll take a closer look. Enjoy some lichen photos I’ve taken during my sojourns. Lichen information this week comes from the USForest Service and the University of California’s Museum of Paleontology here and here.

Lichen on a rock in Idaho

Lichen on a rock at Yellowstone NP

Several small patches of lichen on a rock

Lung lobaria lichen on a tree in Washington

Lichen in the branches of a tree in Washington

Lipstick cladonia on a tree stump

False pixie cup on a tree stump

Bats and White Nose Syndrome

Bats are a misunderstood and unreasonably feared critter. Some species rid our skies of pest insects, while others pollinate crops and other plants. Bat poop (guano) is a rich fertilizer. Attitudes are changing as people begin to appreciate the ecosystem services bats provide but now they face another threat, White Nose Syndrome.

White Nose Syndrome (WNS) is a fungal infection that is destroying bat colonies at an unprecedented rate. The fungus Pseudogymnoscus destructans was likely introduced from Europe inadvertently. It thrives in the cold strikes bats when they are hibernating. Bats hibernate to conserve energy when their food source (insects or fruit) is unavailable, but the infection causes them to wake from hibernation. Being awake increases metabolism and other bodily functions, and the bats starve to death because of burning through whatever energy they had stored to make it through the winter. To answer your next question, “How does being awake kill a bat?”, most of the calories you need in a day are just to keep you alive- breathing, circulation, and the biggest energy consumer- temperature regulation.

WNS spreads from direct contact with an infected bat or from surface contamination inside a bat cave. People can transport the fungus from cave to cave, so spelunkers must decontaminate clothing, shoes, and equipment in between caves. 

Bats infected with WNS (National Park Service photo)

WNS has killed millions of bats in the eastern parts of the US and Canada is spreading west. Last year the first case was discovered here in Washington. Washington Department of Fish and Wildlife conducted a bat count a few weeks ago at Northwest Trek as the beginning of an effort to monitor bat colonies and WNS. A follow-up count took place this past weekend and I took part.

The goal is to count the number of bats seen leaving and entering the nest. Exits minus entries is the total number of bats seen. The tricky part is seeing them as it gets darker. I did OK with this until about 9:20. The freaky part is not seeing the bats until they are inches from your face, then they turn away at the last second, mostly to my left. I could their wings flapping as they passed by my head.

By establishing a baseline this year the state hopes to track population trends that could indicate colonies in trouble. This can be tricky, though. Bats sometimes tend to not roost in the same location night after night. For example, the site I counted was unmonitored in the previous count. The only reason I was posted there was because on the way into Northwest Trek we heard the bats making sounds inside the park entryway. My total for the night was around 60 bats. Other sites inside the park had a lower count than during the previous survey. It is possible that my site had an increase since the last survey, but that is unknown since no one counted there the first time. 

Me counting bats

In just six years since its introduction, WNS had killed millions of bats with a mortality rate up to 100% in some colonies, according to the US Fish and Wildlife Service. Fighting back will be a long process, but the key first step is monitoring. I am glad I had a chance to take part in the beginning of what I hope will be a successful fight. WNS info this week comes from the National Park Service, one of many partners in the search for a cure.

NPS: https://www.nps.gov/articles/what-is-white-nose-syndrome.htm

USFWS: http://www.batcon.org/pdfs/USFWS_WNS_Mortality_2012_NR_FINAL.pdf

Species of the Month- Black Cottonwood

It’s May so why is it snowing? That’s not snow floating in the breeze and accumulating on the roads, it’s the seeds of the black cottonwood tree. Like dandelions, the black cottonwood’s seeds are attached to a white feathery substance. Allergy sufferers throughout the west lament this time of year because of the cottonwood snow.

Scientific name: Populus trichocarpa

Kingdom: Plantae (plants)

Class: Magnoliopsida (dicots)

Order: Malpighiales

Range: Southern Alaska to northern Baja California east to western Montana and Alberta

Habitat: Riparian woodlands, moist areas

Lifespan: 70 years on average

Diet: Sunlight, carbon dioxide, water, and soil minerals         

Predators: voles, mice, rabbits, deer, elk, slugs, insects (moths, tent caterpillars, borers), fungi

Conservation Status: No special protection

Other Information: Black cottonwood is the largest western hardwood species. Every cottonwood I’ve seen is near water. Not surprising then that it takes forever for the wood to season before you can burn it. Because it is usually found near water, it can be a great tool to use if you get lost in the woods. Look for the tall tree with glossy leaves and follow the water downstream to civilization. It is used to make pulp and veneers. In addition to windborne seeds on those cotton tufts, cottonwood also reproduces through cloning. Stumps will sprout and cutting can grow into a new tree.

This week’s information comes from USDA’s Forest Service Silvics Manual. Lifespan information come from Northern State University.

This cottonwood is estimated at about 140 feet tall

The glossy leaf. Note in the background the lighter underside of the leaf

A look at the thick bark

USDA: https://www.na.fs.fed.us/spfo/pubs/silvics_manual/volume_2/populus/trichocarpa.htm

Northern State: https://www3.northern.edu/natsource/TREESA1/Easter1.htm 

Amphibian Egg Mass Surveys

One of the things I do in my spare time (for self-serving fun and career development as well as stewarding my planet) is volunteer with Northwest Trek and Washington Department of Fish and Wildlife conducting amphibian egg mass surveys. No, I don’t go door to door asking questions about egg masses. I go to a pond and look for the eggs that several species of amphibians left behind following breeding.

            First, what is an amphibian? It’s a critter that leads a double life as both a terrestrial and aquatic animal. Unlike a reptile like an alligator that must surface to breathe, amphibians can breathe above or below water. The word amphibian comes from the Latin amphi bios meaning two lives.

            There are 27 species of amphibians in Washington, but WDFW only has us looking for the eggs of 8. They are Oregon spotted frog (state endangered, federally threatened), red-legged frog, American bullfrog (invasive to the Northwest), Pacific tree frog, western toad (candidate for listing as federally threatened or endangered), Northwestern salamander, long-toed salamander, and rough skinned newt.

            The pond I survey is in Eatonville. In and around, I have found eggs, tadpoles, or adults of four of those species. There were Northwestern salamander, Pacific tree frog, and red-legged frog egg masses; adult Pacific tree frogs, a red-legged frog, and American bullfrogs; and some tadpoles that were too fast to be able to identify.

American bullfrog

Red-legged frog

Pacific tree frogs

            To conduct a survey, I go into the pond with my partner Roger and slowly walk around looking for eggs. It seems like a challenge at first, but the egg masses are very obvious in most cases. Northwestern salamander egg masses are a huge solid ball of jelly, about the size of a grapefruit. They are likely to be attached to a pond lily stem. Pacific tree frog masses are smaller balls of jelly attached to smaller aquatic plants in most cases.

Northwestern salamander egg mass

Pacific tree frog egg mass

            When we find egg masses, we mark the location on a GPS and take a picture. It also gets logged on a tracking sheet. Last March the batteries in either the GPS or camera died and the spare batteries in our pack were also dead. It was a little frustrating switching batteries from one device to the other, especially because that was the day a river otter was helping us. It would’ve been great to get a shot of that little guy! As a consolation, we found a pile of his poo.

River otter scat

            Gently cleaning our waders before and after conducting a survey is a thoughtful way to help prevent the spread of invasives from one pond to another. It can also help reduce the spread of chytrid fungus, which causes disease in amphibians.

            The data we collect gets sent to the state to help biologists determine habitat conditions and species trends. Amphibians are an indicator species (species that can indicate trouble in an ecosystem by absence or presence) because their thin skin makes them very sensitive to environmental changes. By identifying trouble early on, biologists can analyze and correct the situation.

            Now you have a glimpse inside the working world of a nature guy. I’ll be back in the pond for a third season of egg mass surveying, starting this week. Weather permitting, of course. Don't forget to like Nature Minute on Facebook!

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)