General Ecology

Autumn among the beeches

Ian Stewart

If life is getting you down or you’re feeling particularly stressed why not take a gentle afternoon stroll through a beech wood? Walking through a beech wood in the fall is a serene experience that will instantly melt away your troubles. And if you look closely, the beeches have a few surprises in store…..

The American Beech (Fagus grandifolia) is a fairly common tree across almost all of the eastern United States and is easily recognized by its smooth, pale gray bark and its above-ground ‘knees’ formed by the tops of its shallow roots. We have several stands of old, large beech trees around our DNS sites because early settlers tended to leave them alone as they often grow on hillsides which aren’t attractive sites for home building or farming, and also because their hard wood is difficult to cut.

At this time of year the ground beneath a beech wood is littered with a carpet of their golden leaves and if you wait long enough you will see a variety of mammals and birds rustling though them in search of fallen beech nuts. These distinctive triangular nuts emerge in pairs from their tough, furry husks when ripe and are beloved by deer, squirrels and Blue Jays and were apparently the favored food of the extinct Passenger Pigeon. Beech nuts are edible to humans once they have been peeled although they are apparently bitter and may even be toxic in large quantities so we do not recommend that you eat them.

Part of the reason beech woods are so attractive to walk through is that they are remarkably open, with very little understory of bushes or shrubs to navigate through. This is because beech trees are thought to be allelopathic, meaning they exude a chemical into the soil around them which inhibits the growth of other plants. Sometimes the only plant you see growing near a beech tree is a ring of ‘root sprouts’ growing around its trunk, which is a direct way through which beech trees spread in addition to their nuts.

Still, despite their placid outward appearance beech woods are tinged with intrigue. If you get down on your hands and knees you will notice that most of the trees have a circle of mysterious brown weedy stems around their base. These are known as Beechdrops (Epifagus virginiana) and are among a handful of plants that don’t photosynthesize but instead live parasitically by burrowing into the roots of beech trees and extracting their nutrients.

So please take the time to explore a beech wood this fall, but be sure to appreciate the small struggles going on underneath these giant trees!

by Dakin Hewlett, Watershed Education Coordinator

DEEC staff member tags and releases a Monarch Butterfly.

Visitors watch as a DEEC staff member tags and releases a Monarch Butterfly. Photo by John Harrod

Fall not only brings the oncoming burst of changing colors, but also marks the beginning of the monarch butterfly’s incredible migration to Mexico. The DuPont Environmental Education Center highlighted the butterfly’s unique journey at their 4th Annual Marsh & Monarch Celebration on September 23rd. Blue skies and sunshine greeted over 200 people who came out to celebrate the tagging and releasing of 8 monarchs. Leading up to the event, DEEC staff and visitors watched and waited as the reared butterflies transformed from caterpillar to chrysalis and finally to beautiful monarchs ready for release.

When the highly anticipated release date came, eager groups of visitors gathered on the boardwalk with a DEEC staff member to learn about monarchs and their important relationship to the milkweed plant. Adult monarch butterflies lay their eggs on the plant and the caterpillars then eat the milkweed as their sole food source. If you want to attract more monarchs to your garden, planting milkweed is a great way to do just that!

Each butterfly was then tagged with a special tracking sticker for research being done at the University of Kansas. Tagging helps monitor monarch migration patterns and the overall health of the population. Finally, the moment came that we had all been waiting for…A few lucky kids became wide-eyed as a butterfly was placed on their outstretched finger and took a few steps while deciding whether it was ready to take flight. Each time a butterfly took off the crowd clapped and cheered with enthusiasm as the magnitude of the 2,000-mile journey sunk in.

Canoeing the pond.

Canoeing the pond. Photo by John Harrod

Visitors also spent the day enjoying free, interactive activities throughout the marsh. Adults and kids alike enjoyed an on-the-water experience canoeing the pond, learning basic paddling skills, and attempting to navigate the water without getting stuck in the plants.

Many chose to get their feet wet while dip-netting for aquatic animals such as dragonfly larvae, scuds, and small fish. Dip-netting is not only a fun way to explore the pond, but is also a great tool to use when measuring water quality. By studying the biodiversity of the pond, staff members at DEEC can better understand the condition of the water. Guest staff from Stroud Water Research Center echoed that sentiment by providing visitors with a chance to conduct their own water quality tests. Participants turned scientists, learned how to test for pH levels, temperature, turbidity, nitrates, and conductivity with hands on experiments like the one shown below.

A curious visitor uses a turbidity tube to test the clarity of the pond water.

A curious visitor uses a turbidity tube to test the clarity of the pond water. Photo by John Harrod

Inside the nature center many other activities were underway such as “Zuumba like an Animal,” on the 4th floor. If you happened to saunter upstairs you were met with a group of kids hopping around the room like frogs or belting out animal sounds at the top of their lungs.  The 3rd floor stayed jam-packed all day with arts and crafts tables, a bike & kayak raffle sponsored by the Alliance for Watershed Education, and interpreters sharing all things marsh. The “Snapper Lab” on the 1st floor displayed many live animals that call the refuge home such as a black ratsnake, snapping turtle, and green frog. On the way out visitors stopped by to chat with Delaware Nature Society’s Habitat Stewards and left carrying armfuls of free milkweed to plant in their own gardens for the next generation of monarchs. Thank you to all who came out to celebrate and see you next year!

 

Free milkweed plants and art projects to take home after a wonderful day at the marsh.

Free milkweed plants and art projects to take home after a wonderful day at the marsh. Photo by John Harrod

Ian Stewart

American Goldfinches are one of my favorite birds. Their scientific name, Spinus tristis, translates as ‘Sad bird of thorn bushes’ and derives from their mournful rubber-duck like ‘squeak’ call. Personally, I think this name is unfair, as Goldfinches always seem such happy, colorful characters (like the female pictured below) with their jaunty, bouncy flight and excited twittering. They are common birds which can lead to them being overlooked and yet they have two major surprises under their wing.

The first is that they breed very late in the summer. Once you get past mid-August only a handful of birds are still breeding in Delaware but the Goldfinch is one of these select few, along with the related Indigo Bunting and Blue Grosbeak. The main reason we think Goldfinches breed so late is that they feed their young entirely on seeds, rather than invertebrates like almost all small birds, so they have to delay breeding until the seed heads begin to appear. The favorite food of Goldfinches includes Purple Coneflower (Echinacea purpurea) and Wild Bergamot (Monarda fistulosa), as well as a range of native and unfortunately, non-native, thistles.

Goldfinches build beautiful, densely-woven nests of fibrous materials such as thistle down and grasses in which they lay 2-5 bluish-white eggs (nest photographed at Bucktoe Creek on July 23).  The nestlings develop in around 2 weeks and fledge resembling duller versions of their parents with brownish wing bars and dark beaks (nestlings photographed in a different nest on August 5, just before they fledged).

The Goldfinches’ second surprise is that they are the only finch that molts their body feathers twice a year. Both sexes are a drab yellowish-green in the fall and winter, perhaps to avoid being seen by predators like hawks, but become brighter yellow in the summertime. The males are especially striking with their lemon yellow body, jet-black wings and cap, and white tail flashes.

The sight of a flock of Goldfinches feeding in a field of native thistle is enough to gladden the heart of any birdwatcher, and luckily Goldfinches are quite easy to attract to your yard, even in fairly urban areas. You can buy sock feeders of nyjer seeds or tube feeders made specifically for Goldfinches with thin seed ports. Since Goldfinches have such small pointed beaks they are the only common bird in our area that can reach inside and pick out the nyjer seeds. They will also happily eat black oil sunflower seed from a generic tube or platform feeder which has the added benefit of attracting other birds too. Better still, try planting some patches of Coneflower or native thistle in your yard and watch them feed how nature intended!

Ian Stewart, Ornithologist

One of the best ways to connect with nature is to monitor bird nest boxes. Regularly checking the contents of an active nest box lets you watch the whole breeding cycle unfold before your very eyes! It starts with nest building, progresses through egg laying and nestling rearing and then (hopefully) ends with the young birds successfully leaving the nest.

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Using an mirror to count Bluebird eggs

The Delaware Nature Society has a team of eager volunteers who monitor over two hundred boxes spread throughout several properties and every year brings more data and surprises. Our most common occupants are Tree Swallows, Eastern Bluebirds and House Wrens but most years we attract a few Carolina Chickadees, Carolina Wrens and Tufted Titmice. One year we had a White-breasted Nuthatch use one of our boxes – who knows what species might show up next?!

Chickadee on nest

Opening this nest box revealed a Carolina Chickadee sitting tightly on a nest. In these cases we leave the bird alone and retreat.

Checking boxes lets you see for yourself the many differences between each species in the way their nests are built, the shape and color of their eggs, and the appearance of their nestlings, as well as the nesting quirks of different birds. Did you know for instance that House Wrens often add spider cocoons to their nest, probably because the spider hatchlings eat arthropod pests mixed in among the nest lining?

Wren nest with spiders

House Wren nest lining dotted with spider cocoons

Our boxes remain in place year-round and provide winter refuges for both welcome and (slightly) unwelcome guests. Eastern Bluebirds roost in our boxes overnight during the winter, presumably to help them stay warm, and sometimes bundle together in the same box. Last winter one of our boxes at Coverdale Farm Preserve had an enlarged entrance hole and was filled with acorns from the huge old Red Oaks that line the driveway. This was probably a squirrel using the box to cache a supply of acorns to chomp on if a sudden snowfall made food hard to find.

chewed box

acorns

Mice also like to spend the winter in our boxes so we have to bump them out to allow the birds to nest. Can you spot the two mice jumping out of the box?

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We have been cleaning out our boxes to get them ready for spring and the birds are checking them out already so nesting isn’t far away! We can always use an extra person or two to help monitor nest boxes at Coverdale Farm or the Red Clay Reservation near Greenville, or Abbott’s Mill near Milford, so if you want to get involved just give us a call on (302) 239-2334. Boxes only need to be checked once a week and monitoring them makes a great excuse for talking a walk on a summer evening or weekend at these beautiful sites. All of our data are submitted to Cornell University’s ‘Nest Watch’ scheme so we are contributing to science as well as simply enjoying nature.

If you’d rather put up your own nest boxes why not join our upcoming program (April 27th at Ashland followed by a field trip to Coverdale on April 29th) to get advice on how to design and position boxes in order to attract nesting birds to your property? Having birds nest in a box you built yourself is a tremendously satisfying experience that may be repeated for many summers to come!

Tree swallows on box

A pair of excited Tree Swallows start building their nest in a brand-new box