Prospecting Wood Duck

I spent some time at the vernal pool on Tuesday collecting invertebrates to feed the spotted salamander (Ambystoma maculatum) larvae we are hosting in my classroom. Thousands of tiny Daphnia sp. (seen HERE) can be easily captured by walking the length of the pool with a fine mesh net just below the surface.

I brought an empty SD card along in order to check the game camera currently deployed on our wood duck box. The box was installed in February of 2016. A detailed account of its installation can be seen HERE. Up until this week, the only wood ducks (Aix sponsa) documented around our nesting box were a pair last spring just before the end of school. I took the camera down at the end of April last year assuming there would be no interest from wood ducks that year. This was unfortunate because when I returned last winter to refresh the pine shavings there were egg shells in the box! The species responsible is still a mystery. A female wood duck would line the bottom of the box with dark downy feathers. The only thing in the box last winter were a few tiny egg shells. With the number of cavity nesting birds in Maine, it could have been anything from a songbird to a saw-whet owl (Aegolius acadicus). Needless to say, I plan to leave the camera up for the entire nesting season this year in hopes of documenting any species using the box.

Mystery egg shells found in the nesting box at the end of last year

A pair of wood ducks swim near the nesting box last spring

Upon arrival at the box on Tuesday, I noticed a downy feather clinging to the top of the entrance hole and fresh scratching near the bottom. This is a sure sign that some sort of bird has been in and out of the box recently. I couldn't wait to get back to the room to see what could be on the camera. 

A glimpse into the life of a wildlife science teacher

After sifting through dozens of photos of an empty nesting box swaying in the wind on some recent blustery days, the photo I have been waiting a year for appeared. A lone image of a hen wood duck entering the box was the only wildlife documented over the past couple of weeks.

A hen wood duck enters the vernal pool nesting box. 

There are a couple of possibilities here. First, this could simply be a hen wood duck checking out a prospective nest site. Her lone appearance and failure to return would indicate that she has not chosen our box. However, the downy feathers and amount of claw marks around the entrance hole have the inner optimist in me hoping that this is not the only trip this hen has made to the box. Could it be that she is coming daily to lay eggs and was even inside incubating when I arrived? I have a feeling that the camera may be pointed a bit too low to pick up a small duck landing on and leaving the nest box. It easily picks up larger movements at water level. I angled the camera a bit higher and am crossing my fingers that this hen will raise a brood here this year. If successful, her ducklings will climb to the entrance hole at just 24 hours old an make the seven foot plunge to join their mother in the pool. In natural tree cavities, some ducklings jump sixty feet or more to the forest floor before being lead by their mother to water. Once down in our vernal pool, they will have all of the invertebrates and amphibian larvae a fast growing duckling could ever need.  The ultimate goal would be images and possibly video of this rarely seen moment in a wood duck's life.  

The American Chestnut

The American chestnut (Castanea dentata) was once the most common and commercially valuable tree in the eastern United States. It ranged from central Maine to southern Appalachia. Legend has it that when settlers first arrived to the new world a gray squirrel could have run from Georgia to Maine without ever touching the ground. It would have done it along the branches of American chestnut trees. These massive trees dropped thousands of pounds of delicious and energy rich chestnuts per acre every year. This is unlike the oaks who generally drop large bitter tasting acorns on a semiannual basis. Their reliability and enjoyable flavor made chestnuts an important food for all wildlife from squirrels to deer and black bears. Humans also relied heavily on this natural food source which was harvested by the ton from the eastern forest every year. They were used to fatten livestock as well as feed families. Holiday songs were even written including this iconic food source being roasted on an open fire. This all changed around the turn of the century when an exotic fungus, known commonly as chestnut blight, was introduced to New York City. By 1930, nearly all American chestnut trees had been wiped from the landscape. Today, the American chestnut is considered "functionally extinct". While the towering specimens our ancestors walked beneath have all vanished, their root systems are still alive within the ground. The blight only kills the living plant above the ground. These last remaining specimens continue to send up new growth, some of which live for up to 10-15 years before finally succumbing to the blight.

The American Chestnut Foundation is a national organization dedicated to the restoration of our eastern chestnut forests. They have been working for decades crossing American chestnut trees with Asian chestnuts that are naturally blight resistant. The goal is to eventually breed a tree that is nearly pure American chestnut but retain the blight resistant genetics of their cousins from Asia. There are signs that they have accomplished this goal but it will be years before a large supply of these trees are ready for the market and mass plantings in our forests. I joined the ACF with my Trees and the Maine Forest class to support this worthy cause and get a really snazzy window sticker. An added bonus to new membership was ten chestnuts harvested from the few productive trees remaining in the state of Maine. We planted them a few weeks ago and have had four come up thus far. Before laying eyes on these seedlings, I had only ever seen one American chestnut tree as a child. Needless to say it was pretty exciting to witness the beginning of what we dream could someday be a towering chestnut tree in the T.A. Forest. While the nuts we received are not thought to be blight resistant, I was still hopeful that we could have some success growing them on T.A. grounds as the ACF does not list any known chestnut trees anywhere in the town of Saco. A ten mile gap between the nearest infected tree is generally good enough to allow a chestnut tree to reach an age old enough to begin producing nuts.

An American chestnut seedling growing in my classroom at T.A. (Photo by Julie Vail)

Today, while working with one of my tree classes in the T.A. Forest, I could not believe my eyes when I took a closer look at a clump of saplings sprouting up ten or so yards form the Eastern Trail. Right there in front of me was a wild American chestnut! I stood quietly trying to talk myself out of what I really wanted it to be while my students conducted their lab work all around me. The more I observed the tree, the more confident I became in what I had found. Finally, I shouted to get everyone closer and we all shared in the excitement of our new discovery. This specimen is just leafing out but the leaves already show the prominently toothed margins and long narrow shape indicative of this species. One of the most confirming features of this specimen is the dead standing tree growing from the middle of the clump of saplings. This is classic for a tree that struggles to grow above ground for more than a decade before being snuffed out by blight. I can't help but wonder how old the root system of this tree is and what the original specimen must have looked like. It is growing beneath some 70' tall eastern white pines (Pinus strobus) that most likely sprouted around the time Thornton Academy was in its infancy during the 1800s. At that time American Chestnuts would have been one of the most common deciduous trees in the area.

New American chestnut leaves in the T.A. Forest (Photo by Julie Vail)

Note the standing dead tree at the center of the clump of saplings. This individual was most likely killed by blight after several years of growth. The small trunk to its left has leaves on the upper half but the lower branches look to be infected.  (Photo by Julie Vail)

While the excitement of finding a wild chestnut growing in our forest has still not worn off, there is a slightly somber feeling as well. Having an infected tree in our area means that there is also blight in our area and our new seedlings are almost certainly doomed. All we can do is hope that our trees can make it long enough to act as ambassadors of an embattled but resilient species. In the mean time, we will allow the leaves on our wild specimen to mature before harvesting them and sending them off to the American Chestnut Foundation to confirm our identification an possibly list the only known American chestnut in Saco.

Touching an American chestnut is like reaching back into another era. It is hard not to wonder what our eastern woodlands would look like today had the blight never been introduced to North America. (Photo by Julie Vail)

Special thanks to Trees and the Maine Forest senior student, Julie Vail, for her amazing photography for today's post.

Busy Morning at the Vernal Pool

While all of the wood frog and spotted salamander breeding activity has come to a close in our vernal pool, there is still plenty of life to observe. We had a great outing during block one today checking in at our pool. Our basic mission was to return some of our classroom wood frog tadpoles in order to keep our tank from overcrowding. Our tadpoles were brought in as eggs early last week and have grown rapidly ever since. The ones returned to the pool this morning have gotten a notable head start on their brethren who have remained in the pool. They are equivalent in size to where they would naturally be in June. This gives these lucky individuals a better chance at reaching metamorphosis before the pool dries up mid-summer.

Wood frog tadpoles ready to be returned to their natal pool

I brought my new camera along for the walk this morning which up until this point has seemed more like wildlife repellent than a useful blogging tool. I'm glad I did as we observed several cool vernal pool visitors. The first sighting was of a beautiful american bittern (Botaurus lentiginosus). Luckily for us, this secretive bird fluttered up into a bush and struck its "concealment pose", doing its best dead stick imitation. Had it just remained motionless at the edge of the pool we never would have seen it. Bitterns are heron-like birds that wade quietly in the shallows feeding on frogs and small fish. To an american bittern, a vernal pool is an all you can eat buffet. Perhaps the coolest feature of the american bittern is its low pitched breeding call. This sound is often described as a rock dropping into the water and is achieved by gulping air into its esophagus.

An american bittern striking its "concealment pose"

After spending a few minutes sitting quietly and observing the pool as a class, amphibians began to appear seemingly out of nowhere. First came a green frog (Lithobates clamitans) resting along the edge of the pool.

A green frog along the edge of the vernal pool

Finally, an especially observant student spotted a spring peeper (Pseudacris crucifer) clinging to to some vegetation in the water. Spotting a spring peeper without it moving first is a feat few can claim. These tiny tree frogs have amazing camouflage and while impossible not to hear this time of year, they are rarely observed.

 A secretive spring peeper in the vernal pool.

Note the sticky toe pads and diminutive size of this adult peeper