Sprouting Acorns

As I’ve visited schools with my ecologist-in-residence program I’ve noticed some very good acorn crops, what ecologists would call mast. Some naturalists that I have talked with have noted that where they are there are fewer acorns. There seems to be a cycle of good acorn producing years then there are years with little acorn production. It would be interesting to note each year how the acorns are in your woods. If you keep a record of what you find you might note this cyclical change in acorn amounts.

At the Bell Top School in the East Greenbush Central School District there is a tremendous acorn crop this year. I’ve noticed that some of these acorns are already sprouting. These acorns come from the chestnut oaks.

These acorns gave me a chance to explore how seeds grow into trees with the students at Bell Top. I like to explain to them that a seed is really two things – a baby plant (in the case of the acorn, a baby oak tree) and the baby’s lunch box loaded with food packed away by the parent plant (in this case, the parent oak tree). I gathered up some of these sprouting acorns to investigate.

Many of the acorns, like this one, had yet to sprout.

Now and then, as we see here, we’d find one that had a small root beginning to break through the shell of the acorn. The first thing to grow on the young tree is this root. It's called a tap root.

Finding these sprouting acorns made for an excellent use of Billy B’s rhyme from Billy B Sings About Trees (see links to the right) –

The roots grow deep
Deep into the ground
Search for water
Drink it when it’s found

If you carefully cut open the acorn you can see the baby tree, what scientist would call the embryonic tree or growth. Look carefully here at tip of the pointer and you’ll see the embryonic tree, which is slightly discolored and tear shaped. All the rest of the acorn, the white material that fills up the bulk of the acorn is the food that the growing embryonic tree will need. This food was made in the green leaves of the parent tree – remember “Green Leaves Make Food!”

The root will use the food in the nut which is stored in what is called the cotyledons. There are two cotyledons in a oak seed. That’s why oak would be grouped with the dicots, plants with two cotyledons. As the oak seedling grows the cotyledons would form the beginnings of a shoot that would grow from the top of the root. As the cotyledons emerge they grow upward and take on a green color as they begin to produce chlorophyll. And not too soon, for as the food stored in the seed is about all used up the green portions of the shoot will start to produce food for the growing seedling. See my blog for pictures of a maple seedling showing this growth (click on May 2009 in the archives and go to May 24, 2009).

Skunk Scat at Bell Top

At Bell Top School with Mrs. O'Connell and her 3rd graders we discovered some scat on a culvert pipe cover. After doing some research using two books in particular (Mammal Tracks & Sign: A Guide to North American Species by Mark Elbroch and Tracking and the Art of Seeing: How to Read Animal Tracks and Sign by Paul Rezendes) my best guess is that it was from a skunk.

The photos in both books did not look exactly like the scat we found, pictured here. Nor did they look like the pictures of opossum scat. They were too small to be raccoon scat. In reading about the scat I found that skunk scat can be quite variable.


What has me thinking that the scat is likely skunk is that near by there are several places where there are holes dug in the ground by skunks. Skunks dig into the soil to feed on beetle grubs and other invertebrates that live there including yellow jackets. A good friend of mine, Rick Glatz, told me of a time he was doing a nature walk with students and they observed a skunk digging up a yellow jacket nest. The yellow jackets were swarming all around the skunk, yet the skunk continued to devour the nest oblivious to the insects trying to sting it.. Here is a picture of one of these holes from the Bell Top school yard where it was likely eating beetle grubs.

Here’s a song I learned years ago about a skunk.

The Skunk Song (sung to the tune of “Dixie”)

I stuck my head in a little skunk’s hole
The little skunk said “Oh bless my soul”
Take it out
Take it out
Take it out
Remove it!

Well I didn’t take it out and that little skunk said
If you don’t take it out you’ll wish you had
Take it out
Take it out
Take it out – psssssssssst
I removed it.

In the song the skunk give three warnings – “Take it out, take it out, take it out”. In reading old accounts of skunks like those by Ernest Thompson Seton they tell of skunks giving three warnings when threatened by danger; the first, stomping their front feet on the ground; the second, making a hissing noise and showing their teeth; and finally, raising their tail. All of these are warning signs to ward off a predator. If successful, the predator leaves the skunk alone and the skunk doesn’t have to use any spray, thus conserving spray for when it really is needed.

I’ve always wondered if this was really true. I had a chance to check it out one day when I encountered a skunk at the Rogers Environmental Education Center in Sherburne, NY. It was a late winter day with mild weather and snow still on the ground. At that time of year skunks are starting to become more active moving about searching for food and getting ready for the mating season.

I was walking one of the Center’s trails when I saw a skunk near a corn crib wildlife feeding area. I was about 50 feet from it, a safe distance if the skunk were to spray. I decided to see if the skunk would give the three warnings. I made a snow ball and carefully tossed it toward the skunk. I missed by about 15 feet. The skunk gave no reaction and continued to slowly waddle along. To improve my accuracy I decided I had to get a little closer, made another snowball and tossed it. Again I missed (I wasn’t trying to hit the skunk, just trying to land the snowball near it), but by only 7 or 8 feet. The skunk just waddled along. So I got even close, less than 20 feet from the skunk, within spray range if it decided to let loose.

I tossed another snowball and almost hit the skunk on the head. It didn’t stomp the ground with it front feet. It didn’t hiss or bare its teeth. It stopped waddling and immediately raised its distinctively marked black and white tail. I thought, “Ooops!” and stood still. The skunk didn’t spray. After a few moments it began to slowly waddle along and then slowly lowered its tail. I slowly backed away.

I didn’t see any feet stomping, hissing or baring of teeth. I definitely saw the tail rise. The skunk had given me a warning. It worked! I left the skunk alone and it continued on with its business not having had to use any spray.

In hind sight it would have been interesting to have been sprayed. Then I could relate the experience of how the spray works – by causing eyes to water, irritation of the nose (I have had that experience when a skunk sprayed in the wood shed attached to our old farmhouse – the smell seeping into the house was so strong that it awoke me from my sleep with a burning sensation in my nose and watering eyes) and even vomiting.

One last note – notice the seeds in the scat. The large ones are cherry pits. The skunk, by feeding on cherry and other fruit, is helping to disperse those seeds. The fleshy part of the fruit is digested while the seed continues through the skunk’s digestive system. When the skunk goes to the bathroom they are planting trees and bushes far from the parent plant. Alas where this skunk went to the bathroom is a bad place for the seeds to have ended up in that they will not be able to grow on the metal plate.

Caterpillar at Sapphire Elementary

I’ve just finished up my fall visit at the Sapphire Elementary School in Monroe, NY. Kindergarten and 1st graders had the chance to be ecologists with me exploring the schoolyard ecosystem. Our trips into the lawn and forest edge revealed many different plants and animals. We found the typical herbaceous plants of the schoolyard lawn – red and white clovers, dandelion, crab grass along with a number of other grass species, yarrow, common and English plantain and trees – red, sugar and Norway maples, Norway spruce and white ash.

Several classes had the opportunity to see a variety of different birds. Blue jays and turkey vultures were seen by almost all the classes. One class had the opportunity to observe about a dozen Eastern bluebirds flit about a schoolyard fence and nearby power line. At one point we saw a male fly up from the ground and land on the wire with a caterpillar or worm in its mouth. Another group witnessed three broad-winged hawks and two osprey fly by on migration. Missing from the usual creatures observed on these autumn field trips was the monarch butterfly. In past years several dozen monarchs would be observed on our walks. This year we only saw two. We wondered what might have caused this decline in monarchs, something that has been observed and talked about by other naturalists and environmental educators throughout the state.

Late summer and fall is a great time to observe caterpillars. They have spent the summer months growing up and their larger size makes them easily visible as they prepare to overwinter. The wooly bear is probably the most familiar of the fall caterpillars but there are many other candidates to discover. We encountered one such caterpillar, one that I had never seen before. I had to tell the students that I didn’t know what it was and that I would have to do some research to figure it out.

Using “Caterpillars of Eastern North America” I was able to figure out that the caterpillar, shown here, was a Ruby Tiger Moth. It’s scientific name is Pragmatobia fuliginosa, a relative of the Wooly Bear (Isia isabella) in the moth family called Arctiidae. The caterpillar eats a lot of different plants including goldenrod, plantain, sunflowers and ash - there are ash trees and plantain in the Sapphire Elementary schoolyard.

The caterpillar will hibernate for the winter and form a cocoon in the spring. The adult moth will come out of the cocoon after it has undergone metamorphosis. It's body will be a dark reddish brown with a row of black spots along the back of its abdomen. The front wings will be a dull reddish brown with one small black spot on each wing. The hind wings will be a pale pink, also with one small dark spot on each wing.

Other caterpillars I’ve come across in my travels include the Galium Sphinx (Hyles gallii) and Trumpet Vine Sphinx (Paratraea plebeja).
















Here are two caterpillars that I found recently (this past late summer and fall) in my travels but have not been able to figure out what species they are. Do you know what they are?

















Keep your eyes open for caterpillars in the schoolyard. The big brightly colored ones provide a great hands-on teaching opportunity about the diversity of life in the schoolyard, life cycles, food chains, animal behavior, and adaptations.