Pond Life

Having spent three seasons doing amphibian egg mass surveys, I can tell you that there are two kinds of people: those who look at a pond from the outside and just see a pond, and those of us who have been in a pond and have seen little world contained within.

Northwest salamander egg mass

Just getting close to the pond changes your view of it. Driving by, you can easily define the shoreline. Walk up to the shoreline and you aren't so sure anymore when the ground gets softer and wetter.
The most obvious pond life is visible before you get to spongy edges. Ducks and geese are patrolling like an avian navy, while a great blue heron flies overhead. Lily pads dot the surface and the whole northern and eastern sides are cloaked in rushes and reeds. If you are still, you might hear the bullfrogs and Pacific tree frogs.

Pacific tree frog

Mallard duck

Put on your waders and step into another world. Look into the water and you'll see insects and their larvae on and below the surface: mosquitoes, craneflies, dobsonflies, and more. Tadpoles and the occasional small fish dart by. A squeak and a splash reveals a startled river otter. Attached to the plant life, you'll find frog, toad, salamander, and newt eggs. Some are below the surface, covered in algae. Some are on the surface, anchored to the stem of emergent vegetation.

Caddisfly larvae

Scoop up a water sample to look at under a microscope. In addition to the floating dirt and plant material, there are tiny shrimp-like critters a quarter inch long. Even tinier are the microscopic algae, protozoa, and bacteria.

Freshwater shrimp- either an isopod or a copepod

If it's a rainy day you won't see much below the surface, but the raindrops take on a totally different sound when they are falling all around you and only landing on more water.
I hope you enjoyed today's aquahike. Ponds are full of life, even if hidden in plain sight. It's a fragile ecosystem, so be kind to your local ponds.

Caution: beavers working

Species of the Month

Easter has come and gone, but the memory remains. Last year we took a look at the cottontail rabbit and this year the Easter species of the month is currently filling our ponds and creeks with quacks but will soon be joined by tiny peeping sounds. Enjoy a brief profile of the mallard duck.

Easter ducklings with mother

Scientific name: Anas platyrhynchos

Kingdom: Animalia (animals)

Class:   Aves (birds)

Order: Anseriformes (ducks, geese, and swans)

Range: North and South America, Eurasia, north Africa

Habitat: ponds, wetlands, streams  

Lifespan: 5-10 years, oldest known was 27 years

Diet: plants, insects, worms, small crustaceans, cereal crops

Predators:  foxes, coyotes, birds of prey, humans

Conservation Status: no special protection

A group of mallards enjoying a warm spring day together

Mallard hen on the go

Other Information: The mallard is the most common waterfowl species in the world. They have adapted to life with humans, but still display a fear (which you’ve noticed if you ever tried to pet one in the park). They are dabbling ducks. Dabbling is what they do to eat- flipping head down in the water, tail up in the air. The females do the quacking. Mallards also make a sound that I describe as muttering at you under their breaths. Females lay clutches of 9-13 eggs in a nest on the ground. After hatching, ducklings follow mama to the water, never to return to the nest. However, there is always an exception to the rule. Mallards nested in a tree at my parents’ house, to everyone’s astonishment. Both male (drake) and female (hen) have iridescent feathers on their wings, and the drake also has an iridescent green head.

Mallard drakes, complete with iridescent green heads

Bottoms up! Dabbling drake

This week's information comes from University of Michigan's Animal Diversity Web. Species comparisons will return next week. Stay tuned and be sure to like Nature Minute on Facebook.

Mr. Frog and Mr. Toad

Part 4 of a continuing series on differences in similar critters brings us the frog and the toad. If you’re new to the show, or have a bad memory, you’ll recall that last year (and the previous two seasons) I was slogging through a pond looking for eggs belonging to frogs and toads (as well as newts and salamanders). They are out laying their eggs as we speak, so this week’s is a timely topic even if it has nothing to do with egg laying.

Frogs and toads are both amphibians, meaning they can breathe on land or in the water, and have similar body shapes. So how can you be sure which critter you’re looking at? Here are a few differences to help you figure it out.

Frogs are generally more aquatic than toads, although there is variation of aquaticness among both frogs and toads. Frogs have smoother skin, a taller and narrower body, and buggier eyes. When moving on land, frogs are magnificent jumpers. The hind legs are long and powerful.

Bullfrog with smooth skin and bugeyes

Cascades frog- note the long legs

Toads are famous for their warty skin, which will not give you warts. The body is wider and flatter than a frog’s. Toads don’t jump much; rather they walk or take small hops. The hind legs are shorter than a frog’s. Their eyes aren’t nearly as bulging as a frog’s. A frog is more likely to be near water, while a frog feels more comfortable straying from the water.

Western toad with bumpy skin and squat little body

Wyoming toad- note the shorter legs and less bulgy eyes
(USFWS)

If you ever encounter one of these critters in the wild, or even just your back yard, hopefully this helps identify what you’re looking at. Info this week comes from Kidzone. Next week we take a break from comparing similar species but the series will resume in April.

What Otter Is This?

Otters are terribly cute little critters. There are several species worldwide, but in North America we have the river otter and the sea otter. Other than one living in a river and one living in the sea, what are the differences? If you should happen to see an otter near the coast, how do you know which one it is?

It might seem silly to not know what otter you are looking at, but coastal river otters will swim into the ocean. Now that you can’t always rely on the type of water to tell the otters apart, what do you do?

You probably won’t have the two otters side by side for a comparison, but the sea otter is much larger, twice or even three times the size of the river otter. The sea otter’s tail is shorter and flatter, while the river otter’s tail is about half the length of its body. River otters have a more rounded nose than sea otters, and the river otter’s nose farther above the mouth. The sea otter’s nose is slightly pointed at the top and the bottom comes to the mouth much like a cat’s. The sea otter has very dense fur, which is why they were hunted to near extinction. The river otter has a course fur and a layer of fat.

Sea otters at sea (Marine Mammal Commission)

River otter swimming

Movement is a good indicator of which otter you’re looking at. Sea otters swim almost exclusively on their backs, using their bellies as a dinner table. River otters swim on their bellies (riding very low in the water) and usually eat on land. On land, river otters move quite well, running with an arched back or sliding downhill on snow. Sea otters rarely come ashore, and when they do, they are clumsy critters that waddle more than they walk.

Sea otter ashore (Oregon Zoo)

River otter on land (Smithsonian National Zoo)

Hopefully you will be lucky enough to find yourself in a position that you see an otter and wonder what kind it is. Sea otters live exclusively on the West Coast and are a threatened species so you will be lucky indeed to find one. River otters have suffered in the past due to hunting and trapping pressures just as their seafaring cousins, but have had a more successful recovery thus far and enjoy no special federal protection.

So you’re far more likely to see a river otter based on population and range. Still, seeing a river otter is a special event. I’ve come across them in the wild twice, and both times it was an unexpected delight. The first otter was in my pond while I was surveying amphibian egg masses. The second was in Capitol Lake in Olympia, WA where I was joining a group for an evening bat program. Check your local waterways; you may be in for a pleasant surprise too!

This week's otter information comes from the Seattle Aquarium. Don't forget to follow Nature Minute on Facebook!

Marsh Madness

One of the most important habitats is wetlands, where the only buzzer-beater you’re likely to find here is when you swat at a mosquito or fly. Among the most productive of all ecosystems, wetlands provide food, water, and shelter for a dazzling array wildlife. Additionally, wetlands benefit people too. Besides recreational opportunities, wetlands provide flood control and water filtration. Not only are there freshwater and saltwater wetlands, but different varieties of each.  

Salt marshes are wetlands that flood with salt water at high tide. Obviously, they are found in coastal areas. They are a common feature in estuaries, areas where salt water mingles with fresh water. They are important habitat for seafood, including salmon, shrimp, and crab. The food our food eats is what draws them there (and the young salmon acclimate to the salt water), but they draw the critters that eat them. Salt marshes are important habitat for resident and migrating shore birds.

Saltwater marsh, Puget Sound

Saltwater marsh, Puget Sound

Freshwater wetlands are more varied. They include bogs, swamps, fens, and seasonal wetlands. Even shallow ponds are considered wetlands. The pond where I conduct my amphibian egg survey is considered wetlands.

Shallow pond freshwater wetland

Freshwater wetlands perform the important ecosystem services of flood control and water filtration. Wetlands do this by impounding rainwater and slowly releasing it downstream or absorbing it into the soil. They filter water by allowing sediments and pollutants settle out. Low water velocity lacks the necessary energy to carry those particles.

Like their salty counterparts, freshwater wetlands host a diverse community. In my pond, I have found two species of salamanders; three species of eggs; one species each of fish, freshwater shrimp, and snake; a river otter; insects galore; and birds too numerous to count. I have also seen deer and elk, coyote, and raccoon tracks and scats near the pond. I have no doubt that these critters are drinking from the pond.

Wet meadow wetland, Mount Rainier National Park

Just this morning I found myself in wetlands once again. This time the focus was on remove protective plastic tubes from trees that were planted three years ago. This site is in Washington’s Ohop Valley. The wetlands are seasonal freshwater, and since this is the rainy season the lands were wet. I didn’t notice much wildlife since I was looking down, but I did happen to see a ton of spiders and elk tracks and scats. The trees are important because they will shade out the invasive reed canary grass (which is swallowing everything) and cool the water temperature in the stream for the salmon. Water tolerant species such as willows were the most common tree I saw, and there were some others I didn’t recognize without leaves in the higher and drier areas.

Next time you drive past a soggy area, don’t be repulsed. Thank a wetland for your seafood and drinking water. Give a hoot and help protect our wetlands! Salt march information comes from our friends at the National Oceanic and Atmospheric Administration, while Washington State Department of Ecology provided information on freshwater wetlands ecosystem services.

NOAA (salt marshes)

WA Ecology (water filtration)      

Amphibian Egg Mass Monitoring

So far this season, I've been out to the pond five times with my partner Roger. We have found mostly Northwestern salamander eggs, solid heavy balls of jelly. There were a few long-toed salamander eggs out first time out. The second time out it snowed the whole time. Standing in a pond, surrounded by falling snow, is a very odd sensation. Unlike rain, snow falling on a pond leaves no ripples. Visibility was not diminished at all, unlike yesterday's survey. We had to quit early because of rain. To someone who has never looked into a pond the way I do, rain might not matter. But those ripples by the hundred make a continuous succession of tiny waves that make it impossible to see through the surface. Yesterday also marked the first time we heard the Pacific tree frogs chorusing around us. It was only a few, but it almost felt like I was surrounded. The real chorus started at night. I had to take a walk, and went past a different pond. It was abuzz with tiny frogs, all calling for mates. I decided to shine my flashlight in there to see if I could see any of them. One of them heard my footsteps and thought I might be a threat. It stopped calling. Withing seconds, the pond was silent. That is a defense mechanism you my have encountered. If you've ever heard a frog and tried to find it you know they stop croaking when you get too close. In a sea of green, you can't find that little green frog without following your ears. So it is with predators. I read about this reaction in Merlin Tuttle's "The Secret Life of Bats", in a chapter about frog-eating bats. It was my first time experiencing an entire pond going silent in unison.

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!