Field Trip Archives - Page 2 of 9 - Eva Varga

September 27, 20134

Prior to our departure for holiday in China, we had enjoyed the new DreamWorks movie, Turbo. Snails were thereby on our mind and to the delight of the kiddos, we happened upon a few small garden variety in the ancient gardens of China and at the Panda Breeding Center in Chengdu.  In Yangshuo, we discovered what the locals called Duck Snails, a large freshwater snail belonging to the family Ampullariidae.  The more accepted common name is the Apple Snail, an aquatic gastropod mollusks with gills and an operculum.

apple snails

Field Studies

We first noted the presence of these snails because of the bright pink egg masses that we observed all over the shoreline of the Yu Long (Dragon) River. These egg masses are laid on solid surfaces up to about 20 inches above the water surface. An average clutch contains 200 to 600 eggs, with each egg measuring 0.9 to 1.4 mm in diameter. Soon thereafter, as the kids began to play in the river, we found adult snails in a variety of hues, ranging from creamy yellow to a light pink.

As amateur naturalists, we are not sure exactly what species we observed (Pomacea canaliculata or Pomacea insularum) – perhaps even multiple species.  Based upon our research, we are leaning towards P. canaliculata.  Even so, the kids enjoyed playing with them and watching them glide across the surface of the bamboo boat structure that was anchored near shore.

Sweetie expressed wanting to take them home and of course, I explained that this was not only illegal (customs would certainly not allow us to transport live animals back to the states) but it would also be negligent on our part and potentially environmentally catastrophic.


Phylum Mollusca

When we returned home, I took advantage of their interest in the snails, to engage them in a little nature journaling.  I pulled out a few text books and had the photographs we had taken in Yangshuo available on the iPad.  Sweetie ran to her room and brought back one of the shells she had collected during our stay.  We then got about sketching and noting our observations in our journals.

As they worked, I read aloud a book that I had purchased years ago in Hawai’i, Beyond ‘Ohi’a Valley: Adventures in a Hawaiian Rainforest by Lisa Matsumoto.   The illustrations are very beautiful and the characters are very comical; the storyline tells about the native animals of Hawai’i and the impact of invasive, non-native species.  While discuss how similar problems could occur with the introduction of the apple snail – in fact, it is happening …

Pomacea canaliculata is native to temperate Argentina and northwards to the Amazon basin. Through human introduction, this applesnail has rapidly spread to Indonesia, Thailand, Cambodia, Hong Kong, southern China, Japan, Philippines, and Hawai’i. There are indications that they are invading Australia. In the 1980’s, channeled applesnails were introduced in Taiwan to start an escargot industry. This snail was originally imported under the name “golden snail” or “golden applesnail” for human consumption. However, the Asian escargot market never materialized and applesnails, that escaped or were released, ultimately came to cause extensive damage to rice fields. 

I’ve posted more pictures and information about Pomacea canaliculata onto Project Noah.  I encourage you to hop over if you are interested in learning more about Apple Snails.

Submitted to the Outdoor Hour Challenge Blog Carnival at Handbook of Nature Study.

July 24, 20134

I grew up in Bandon, Oregon and though we now live in the valley of northern California, we travel home as often as possible.  While we go primarily to see family, the ocean pulls us to her just as compellingly.  We have enjoyed exploring the tide pools, investigating the unique estuarine habitats, and tasted freshly caught Dungeness crab many times in the past.  Recently, however, we spent some time taking a closer look and discovering the secret of the tides.

tidal chart

As pictured in the the photo collage above, we visited a beach access area at both low tide (6:59 a.m. @ -1.9′) and high tide (6:56 p.m. @ 1.5′).  I specifically selected this area because on low tide, we had access to tide pools.  Shortly after I took the photo, we walked down the stairway and spent time investigating the marine invertebrates.  While we marveled at the sea stars and innumerable sea anemones, I began to pose questions about the animals we observed and about the wave evidence on the shoreline.  We noted specifically where we found each species and shared our hypothesis for how these organisms could survive in such a dramatically changing environment. I’ll share our discoveries soon – the kids are still working on their nature journals.

Create a Tide Graph

One of the most useful activities we undertook this past week was to create a tide graph and then use the newspaper to also plot the corresponding moon phases.  To create a tide graph yourself, use a tide chart and select a specific month; you can access tidal data from NOAA.  Use a piece of graph paper to  graph the highest high tide and the lowest low tide for each day (recall there are typically two high tides and two low tides each day).  Use a different colored pencil for each tide type.  The day of the month should be on the x-axis and the height of the tide on the y-axis.  Tides can be negative, so be sure to include negative numbers on your y-axis.

Lastly, find a moon phase calendar for the selected month (or look up the moon phase in your local newspaper).  Sketch the four major moon phases (new moon, 1st quarter moon, full moon, and 3rd quarter moon) under the corresponding calendar date and label them accordingly.  After completing the graph, answer the questions listed below.

  • Is there a relationship between the phase of the moon and the tides?  Explain what you observed based upon your graph.
  • What are spring tides? Based upon your data, around what phase(s) of the moon do spring tides occur?  How do you know this?
  • What are neap tides? Based upon your data, around what phase(s) of the moon do neap tides occur?  How do you know this?

Take it Further

If you have enjoyed this activity and would like to explore related lessons and inquiry activities, check out Estuary Ecology, a fourteen lesson hands-on life science curriculum unit study that focuses upon estuaries and salt water marshes.

** Please note that graphs will vary depending upon the selected location and time of year.  A great extension activity is to create tide graphs for distinctly different locations (Newport, Oregon and Cape Code, Massachusetts, for example) and/or different seasons.

Submitted to the Outdoor Hour Challenge Blog Carnival at Handbook of Nature Study.


July 20, 20135

Plastic is forever!  It does not biodegrade, but instead breaks down to the size of plankton.  Rotating ocean currents or gyres are pulling in plastic garbage from every continent in the world and churning it into bite-size pieces.  This debris confuses marine species and litters beaches, even in pristine remote locations.  Can art be used to save the sea?washed ashore

We recently took part in a community art workshop held each Saturday at Art 101 in Bandon.  Community members, local schools, and state parks work together to gather plastic pollution off of beaches.  Through the Washed Ashore Project, the plastics are washed, sorted, drilled, cut, and processed into art supplies.   Lead Artist and Director Angela Haseltine Pozzi leads the community in creating large-scale sculptures of the very sea life that is threatened by marine debris.

Washed Ashore ArtA few facts we gathered from the gallery at Washed Ashore:

  • Over 200 billion pounds of plastic are produced worldwide each year, and it is estimated that only 4-7% of it is recycled.
  • Plastic pollution now affects at least 267 species world-wide.
  • 100,000 marine mammals and sea turtles die annually from entanglement.
  • 80% of marine debris comes from land via streets, storm drains, and rivers.
  • Americans use ~1 billion disposable shopping bags, creating 300,000 tons of waste each year.

In our family, we make a concerned effort to reduce our use of plastics.  I’ll be sharing the steps we have taken in a post next month.

November 12, 20124

Sweetie and I took part in a wonderful outdoor seminar and nature walk earlier today.  Led by a local Wintu elder, we learned about the acorn from harvest to food source.  We were invited to take part in grinding the acorns on a stone with some of the same materials the natives would have used.
Once ground, the acorn meat was put into a jar with hot water to soak over night to help leach out the natural tannins.  The following day, the liquid would be drained out but reserved for use as a Poison Oak remedy.  The acorns after two consecutive days of soaking, would eventually be ground to a flour and then used in cooking.
The Wintu elder brought several dishes to share with us that he had prepared:  acorn candy (roughly ground acorns combined with honey and molasses), acorn muffins (acorn flour with Oak ashes substituted for baking soda), and an acorn bread.  To accompany the breads, he also had butter, local honey (which he preached of its natural healing abilities – in lieu of hydrogen peroxide), blackberry jelly, and manzanita syrup.  In addition, he had prepared a White Fir and Honey tea.
Everything was very tasty – though not as rich and smooth as what you would buy in a store.  After the talk, the elder led a short walk to point out to us some of the native plants and to share with us their uses for food and/or medicinal purposes.  I was proud that most of the plants and their uses we already knew.  I know I could certainly survive if circumstances forced me to live without the comforts we’ve come to rely upon.

Submitted to the Handbook of Nature Study Outdoor Hour Challenges November Carnival.

November 4, 20121

We started purchasing Real Milk when we were still in Central Oregon.  The farmer in Oregon was small scale – milking only two-three cows.  The milk was delicious and it was a weekly treat to drive out to their farm for our milk.  We loved visiting their farm and would often visit with the family, even occasionally jump on the trampoline with their kids.

R.A.W. ~ Real And Wholesome

When we moved to Northern California, we were eager to seek out a local farmer with whom we could  take part in another herd-share agreement. Imagine our excitement when we learned of Duivenvoorden Farms, founded in 1963 by Rita and Gerard Duivenvoorden, immigrants from Holland looking to live the American Dream.

“Back in the 20s, Americans could buy fresh raw whole milk, real clabber and buttermilk, luscious naturally yellow butter, fresh farm cheeses, and cream in various colors and thicknesses. Today’s milk is accused of causing everything from allergies to heart disease to cancer, but when Americans could buy Real Milk, these diseases were rare. In fact, a supply of high-quality dairy products was considered vital to American security and the economic well being of the nation.  What’s needed today is a return to humane, non-toxic, pasture-based dairying and small-scale traditional processing, in short . . .  a Campaign for Real Milk.”  ~ Quoted from A Campaign for Real Milk.

Originally starting with 175 milk cows, they eventually got the herd up to 200. They operated with that herd from 1963 to 1988 ~ doing everything from custom farming, running a beef herd, raising calves, and shipping milk to a local creamery. In 1988, however, the original herd was sold and Duivenvoorden Farms moved on to other ventures.

In 2004, Duivenvoorden Farms began milking cows again, and currently milks 30 cows a day. The Herdshare program was started in 2008 and is now a small, pasture based dairy farm. The herd share program allows owners access to farm-fresh, quality, delicious raw milk from their Grade A dairy.

Now again, we enjoy driving out to the farm, visiting with Marc and his family, and interacting with the many animals (cats, dogs, pigs, goats, and of course the cows).  It is a wonderful feeling to know that we are not only supporting local, sustainable agriculture – but also helping to support local families with the same values as our own.

October 22, 20121
We have been wanting to hunt for letterboxes here at Hog Plateau since we first learned of it in May of this year.  We had attended a Letterbox Gathering that coincided with the Annular Eclipse, but the heat prevented us from – it was over 100 degrees – certainly not ideal for letterboxing. 
Our shadows in the parking lot as we got underway

We thereby opted to wait until autumn, even though we knew that the clues would be more difficult without foliage on the trees.  I am delighted that we waited for another reason as well – back in May, our chief supporter wasn’t really into the sport of letterboxing as the kids and I.  He would tag along and frequently help us to locate boxes – but he didn’t have a signature stamp or trail name of his own.  Since then, he has had a change of heart and has joined the ranks of letterboxers all over the world.


We drove out early in the morning … arriving about 9 a.m.  In this area, there are well over 25 letterboxes.  We hunted for four hours – taking a brief rest now and then to refuel when necessary – still we didn’t find them all.

Buddy enjoying a brief little siesta

Sweetie wins the award for most boxes found … she would run ahead of us and find the boxes before I had even finished reading the clues.  She is quite the treasure hunter.  Dad and Buddy proved to be the most persistent .. finding boxes that even I had given up on.

Sweetie finding yet another letterbox before we even arrived

As per usual, some of the boxes that were originally hid have since been lost. One was believed to have fallen into a hollowed tree trunk.  We thought perhaps we could see it though our arms were not long enough to reach it.  I thereby offered to my husband my survival knife in hopes that perhaps he could poke it and thereby retrieve it.  This didn’t work.  However, as I proceeded to put the knife away, I sliced my right index finger quite severely (not quite requiring stitches, but nearly so).  Funny, as I equipped my day pack earlier this summer, I purchased a first aide kit as well as this knife.  Had I not been using this knife, I would not have had need for first aide.  Ah well.  Live and learn.  Fortunately, it was I who was injured and not one of the kids.

Me … modeling (thankfully) the only injury of the day

We went out for lunch after our adventure and then stopped by the pumpkin patch for our pumpkins.  It was a great day!