The freshwater tidal swamp of the Lewis A. Swyer Preserve in Stuyvesant was the destination of our Natural History Outing on July 6th. The Hawthorne Valley Farmscape Ecology Program facilitates these Natural History Outings as a way to invite anybody to participate in the joy of discovering and documenting the plants and animals of different areas in Columbia County. These outings are not guided nature walks, but impromptu explorations, often at locations we have never (or at least not in a long time) visited ourselves. Please check our calendar if you are interested in participating in future outings.
The Lewis A. Swyer Preserve, which is owned and managed by The Nature Conservancy, was established to protect one of the five largest areas of freshwater tidal swamp in New York. It surrounds the mouth of Mill Creek and is influenced by the twice daily tidal change in water level of the Hudson River (~ 4 feet!) and Mill Creek. To learn more about the regional significance of this type of habitat, please read here.
This posting illustrates some of the plants, plant communities, and animals we found on July 6th, while walking on the 1/2 mile boardwalk that connects the trailhead on Route 9J (2 miles north of Stuyvesant Landing) to a little observation tower next to the railroad tracks at the mouth of Mill Creek.
The trees of the freshwater tidal swamp forest along the boardwalk are mostly Swamp White Oak, Red Maple, and three species of ash (White, Green, and Black Ash).
The most prominent plants on the ground under the trees are Hog Peanut, Skunk Cabbage, and Sensitive Fern.
Canada Lily was a notable presence during our visit.
Some where browsed by deer, who seem to enjoy eating the flower buds, but many were in full bloom.
Canada Lily blossom with its companion plants, Sensitive Fern and Hog Peanut.
Poison Ivy is a constant presence along the sides of the boardwalk with enormous vines climbing many of the trees and forming canopies of their own below and intermingled with the trees canopies. The leaves surrounding the largest bole in this images, as well as the leaves entering the image from the right, are all Poison Ivy. Needless to say, we were very thankful for the boardwalk which kept us at a safe distance from most of it.
Part of our group trying to catch a glimpse of an elusive bird high up in a tree. Otter (in red T-shirt) is trying out his new camera to see if he can get a shot…
… and succeeded in documenting this Great Crested Flycatcher.
The most common shrub along the boardwalk is Spicebush, which was so common that we forgot to take a picture.
However, there were some other interesting plants along the way:
American Hazelnut, which we rarely see with beautiful fruits. And fruits they had…
When in fruit, our two native Hazelnuts are easily distinguished. The fruits of American Hazelnut are surrounded by “fringed” (botanists speak of “laciniate”) bracts (leaf-like structures), while the fruits of Beaked Hazelnut are covered by bracts which are prolonged beyond the nut into a long, slender beak. In Columbia County, American Hazelnut is usually found in the western part, near the Hudson River, while Beaked Hazelnut is the common species found in the Taconics and the hills in the eastern part of the County.
Ninebark is another shrub which is found in our County exclusively along the Hudson River. It is a member of the Rose family, with leaves reminiscent of Hawthorn, but its fruits are dry, four-parted capsules (a bit like the core of an apple without the apple around it).
Carrion Flower (so named because of the somewhat rotten smell of its flowers) is a non-woody vine related to Greenbriar. Its leaves have a characteristic venation with several parallel veins and only very faint cross-veins. The fruits ripen to a very dark blue color.
A Fishing Spider of the family Pisauridae was guarding its nursery web (bottom left), filled with tiny spiderlets. The body of the mother spider was about an inch long.
A Daddy Long-legs or Harvestman, a relative of spiders in the order Opiliones. Daddy Long-legs differ from true spiders in the way they eat: Spiders can only suck liquid food, while Daddy Long-legs can eat small particles of insects, plants, fungi, or dead matter.
This and the following image show two different species of Robberfly or Assassin Fly. This group of insects are powerful predators on other insects. They usually catch their prey in flight and then insert their mouthparts to suck out the juices.
One of the small tributaries draining from the freshwater tidal swamp into Mill Creek at receding tide.
Pickerelweed is emerging at the shore of the creek at low tide. During high tide, most of the stalks are submersed and only the leaves and blue flowers stick out of the water.
A section of the boardwalk near the observation tower. The tree cover is sparser here and allows a dense stand of sedges (Carex trichocarpa) to dominate the vegetation on the ground.
Water Hemlock (Cicuta maculata), one of our most poisonous plants in the County (and totally unrelated to our Hemlock trees, but a close relative of the Hemlock that Socrates took to end his life), stands tall next to the boardwalk, surrounded by the broad arrow-shaped leaves of Arrow Arum.
Another view from the boardwalk into more open vegetation along Mill Creek.
Two Silver-spotted Skippers frolicking around the flowers of Tall Meadow-rue.
This somewhat blurry image was taken at a long distance because we were both curious about the butterfly and the plant, but could identify neither from where we stood. The flower shape fits with Stachys sp., and the plant is most likely Smooth hedge-nettle (Stachys tenuifolia), not American Germander, as we had guessed in the field. The butterfly is one of the Skipper species, most likely Broadwing or Dion Skipper.
This spherical inflorescence belongs to Buttonbush, which was in full bloom and attracted a variety of butterflies and other insects. Here pictured is the Least Skipper. We also saw an Azure and a Little Wood Satyr feeding on Buttonbush flowers.
According to Kathy Schmidt, a local snail expert, who is also known as the talented nature illustrator whose beautiful drawings adorn most outreach materials produced by our colleagues from Hudsonia Ltd., the following (and last) image is of an Ovate Ambersnail (Novisuccinea ovalis), a native air-breathing land snail which loves humid microclimates.