The Nature of Delaware

Abbott's Pond spillway working overtime

The generally slow and meandering Johnson’s Branch has morphed into Johnson’s Swamp, flooding all low lying areas.  While floods and storm surges may be viewed as unpredictable disasters, marine and freshwater edge habitats are inherently dynamic in nature and human land use often influences the severity of these events through increased run-off, reduced percolation, and expensive infrastructure located in these areas.  

Together again: the confluence of Johnson's Branch (top) and the Mill Tail Race (bottom)

This natural process has shaped southern Delaware’s streamside forests for thousands of years.  The periodic flooding of these areas made them difficult to farm or build on, which is the reason that many of these forests still line the floodplains of the region.  Indicator soils, plants, and animals in these areas are adapted to survive and thrive in this dynamic habitat.  The waters deposit rich soil and water-borne seeds, which in turn supports new plant growth, slowly building up the land.  Trees, uprooted by the high waters or wind, provide a damming effect.  All of these events contribute to the alteration of the stream channel. 

Johnson's Swamp? The bright leaves of winterberry and fringe-tree, two denizens of the swamp forest at Abbott's Mill, are visible at the typical stream boundary.

Abbott's Mill outflow. Note the submerged wall to the left of the bricks.

Take the time to look closer at the plants and animals that live along Delaware’s waterways and discover the unique adaptations that allow them to persist through floods and the other extreme, droughts.

The Eagles at Conowingo trip has been rescheduled to Friday, November 20th, 8am to noon.  If you would like to reserve a spot, visit www.delawarenaturesociety.org or call (302) 239-2334 ext. 134.

By Jason Beale, Manager, Abbott’s Mill Nature Center

I look forward to summer thunderstorms in August for two reasons.  First, they provide a welcome respite from the heat and second, they bring the Meadow Mushroom, Agaricus campestris.

Meadow Mushrooms and a toddler, in their natural habitat. Sasha examines the chocolate brown spores on her left hand.

 The Agaricus mushrooms are well known to most people through  Agaricus bisporus, the cultivated button mushroom.  The genus is fairly easy to identify.  Many are white and possess a ring on the stalk or annulus.  The gills are pink when young and dark when mature, producing a chocolate brown spore print.

The pink gills darken with age. Note the fading rings on the stalks.

 They can be readily told from the Amanita genus which is responsible for 80-90% of mushroom fatalities though they share a superficial resemblence.  Amanitas possess an annulus, but the stalk usually emerges from a cup-like volva.  They are associated with tree roots and aren’t common in lawns.  Additionally, they always possess pale gills and produce a white spore print.

 

Another common lawn mushroom that the would-be mushroom-eater should know is the Green-spored Parasol, Chlorophyllum molybites.  It is one of the most common causes of mushroom poisoning (severe gastrointestinal distress) in the United States.    It has an annulus the conical cap is flecked with brown scales.  The gills are whitish to yellow and ripen to gray and green in old age. 

Easily overlooked, the Meadow Mushroom is a widespread and choice delectable.

 

By Jason Beale, Manager, Abbott’s Mill Nature Center

Abbott’s Mill Nature Center has thrived in recent years due to the dedication of staff, volunteers, and partners in state and private conservation organizations.   The land base around the center has grown from just a few acres in the early 1980’s to 106 contiguous acres along Johnson’s Branch. 

Morton Farm, December 2008, looking toward Abbott's Mill

A key acquisition was the 13.8 acre Morton Farm.  This piece sits between the Lindale/Isaacs Tracts and Nature Center/Mill complex on the western edge of Abbotts Pond.  In 2008, volunteers, staff, and the Division of Fish and Wildlife worked to clean-up the site for educational use and wildlife. 

Pond Prep - A human home becomes a home for wildlife

A seasonal pool now hosts breeding Fowler’s Toads and Cope’s Gray Treefrogs where a house stood just a year ago.   A series of bird boxes provide nesting habitat for Eastern Bluebird, Tree Swallow, House Wren, and Purple Martins.

Fowler's Toad Tadpoles in Morton Pool

Exciting changes are currently underway in the roughly 10 acres of fallow farm field.    1.5 acres along the pond edge have been planted with native tree seedlings donated by Milford Parks and Recreation.  The remaining 8.5 acres are currently being planted in native warm season grasses and wildflowers through a USDA, Natural Resources Conservation Service, WHIP (Wildlife Habitat Incentive Program) grant that Delaware Nature Society received.  The grant also includes 6.5 acres in the Lee Meadow to the north of the Nature Center.  Site preparation and planting is slated to be completed by late June.  This site should improve habitat for a variety of insects, mammals, and birds including Grasshopper and Savanna Sparrows.

Grasshopper Sparrow by Chuck Fullmer

This project, with its the native meadows, riparian buffers, and thriving wildlife, is an excellent example of local citizens and conservation organizations coming together to protect and enhance Delaware’s natural beauty.  Thanks to all who have lent a hand.

Upcoming programs with the Delaware Nature Society: Whip-poor-will Evening June 12, Pine Barrens Orchids and other Wildflowers June 18.  See www.delawarenaturesociety.org for more details.

By Jason Beale, Manager of the Abbott’s Mill Nature Center

Reproduction is a major theme for wildlife in the spring and the signs are everywhere if you take the time to look.  It also helps to have knowledgeable neighbors to tip you off to interesting happenings.  Paul Layton, a longtime Abbott’s Mill Nature Center volunteer, called me this morning to report nesting Black Vultures and breeding Eastern Spadefoots. 

Woodland vernal pool with buttonbush

Eastern Spadefoots are toad-like amphibians are immediately recognizable by the yellowish lines along the back and distinct “cat’s eye” with a vertical or diamond-shaped pupil.  They also possess a unique sickle-shaped “spade” on the inside of their hind feet.  They use the spade to dig into the sandy substrates near ephemeral wetlands that comprise their habitats.  This morning, they were singing in a flooded corner of a farm field and in a series of wooded vernal pools. The Eastern Spadefoot is an explosive breeder following periods of heavy rains from spring through fall.  Due to the unpredictable nature of their breeding and their underground lifestyle, I consider any encounters very special.

Eastern Spadefoots mating in a flooded ditch

Spadefoots mate using an embrace called inguinal amplexus, grasping the female behind the waist, but in front of the hind legs.  While embraced, she lays eggs on submerged vegetation.  The eggs hatch in a few days and the development of tadpoles is also rapid with metamorphosis occurring in just a few weeks.  This is essential as breeding pools can dry up quickly.

Inguinal amplexus

 Leaving the Spadefoots behind, Paul took me to an old barn on his property where he has suspected nesting of Black Vultures.  They are ”B-List” species for the 2nd Delaware Breeding Bird Atlas and any documentation of nesting activity is highly sought.  As we approached the barn, a Vulture popped up out of the hole in the roof and flew to a nearby perch. 

Black Vulture nest site

Taking advantage of the vacant nest, we headed in and discovered a single egg.  Nest may be too strong a word as the eggs, usually two, are simply laid on the ground.  However, Black Vultures can be fairly aggressive and make a variety of noises which are probably enough to ward of would-be nest robbers.  

Black Vulture "nest". Note whitewash throughout. It didn't smell great.

The large egg, almost 3″x2″, is incubated by both sexes for 32-39 days.  The young leave the nest around 10-11 weeks, but are dependent on their parents for another two months.

Black Vulture egg

Back at the Nature Center, I came across a female Brown-headed Cowbird laying an egg in a Barn Swallow nest.  While this nest parasite (a bird that lays it’s egg in another bird’s nest) isn’t a favorite among many birders, it was another nest confirmation for the Breeding Bird Atlas.

For more info on amphibians and nesting birds, check out the following:

2nd Delaware Breeding Bird Atlas: http://www.fw.delaware.gov/BBA/Pages/BreedingBirdAtlas.aspx

White, J.F., Jr. and White, A.W. 2007. Amphibians and Reptiles of Delmarva. 2nd ed. Centreville, Maryland: Tidewater Publishers

Baicich, P.J. and Harrison, C.J.O. 1997. Nests, Eggs, and Nestlings. Princeton, New Jersey: Princeton University

By Jason Beale, Abbott’s Mill Nature Center Manager

In many regions of the United States, mid-Spring sends thousands of people into our fields and forests to seek the elusive morel.  Morels are sac fungi (Ascomycota) as opposed to the classic gilled mushrooms (Basidiomycota) and are considered one of the finest wild gourmet foods out there.

Morels have a counterculture all their own with stories of colorful hunters who jealousy mislead would-be pickers to protect a patch.  They tell tall tales of the big find, theories on how and where to find them, and leave legions of salivating hikers in their wake.  Some locations that have proved successful in my morel hunting are under dying elms, around the bases of ash trees, recent burn areas, and abandond apple orchards.  They generally appear after a warming period, especially if it has been wet.  I haven’t heard about too many people finding morels in southern Delaware; they seem to be rather rare here or perhaps a well-kept secret.  However, I know from experience that northern Delaware, Pennsylvania, and the Great Lake States all have well established picking traditions. 

Morel habitat? Expect the unexpected and then jealously guard your patch!

Therefore, we had a nice surprise today when Elliott Workman, Abbott’s Mill Nature Center’s Land and Facilities Coordinator, discovered a patch behind our dumpster under white pines.  “One man’s trash is another man’s…mushroom?”  They were yellow morels, Morchella esculenta.  

 As with all morels, they are readily identified by the brain coral-like head.  The pock marks contain spore sacs that are released into the air at maturity.  A single fruiting morel may produce hundreds of millions of spores in its brief life.  The spores are transported by the wind, ideally to land in suitable habitat.  Morels are saphrophytic with germinating spores producing hyphae (root-like filaments) that feed on decaying wood.  Morels are also completely hollow in the stalk and head.  Experienced morellers know to slice the morels in two in order to evict any slugs, beetles, pillbugs, or other critters that may be hiding inside sharing your meal.  The simplest recipe is to sautee morel halves in butter.  Ah!  The taste of spring!

A word of caution: Please use common sense when experimenting with wild foods of any kinds.  Even “edible” species can produce allergic reactions in certain individuals.   Talk to local experts, study your field guides, and enjoy.

By Jason Beale, Abbott’s Mill Nature Center Manager

Photos by Chuck Fullmer

The weekly Abbott’s Mill Nature Center walk yielded some great birds last Wednesday morning as we close in on the magic month of May.  With chilly winds and the sun playing peek-a-boo, we started our walk at the Lindale Tract.  This woodlot borders Abbott’s Pond and features both swamp and upland forest, making it a great spot to find birds.  A pair of drake Wood Ducks swam near an observation deck and two Eastern Kingbirds chattered as they flew along the pond edge.  Yellow-rumped Warblers were abundant and we were able to find a secretive Pileated Woodpecker.

We took a short drive over the Blair’s Pond Preserve access and scanned with our eyes and ears for the yet to arrive Baltimore Orioles.  Last year’s nest is still visible, dangling from a tulip tree.  Indeed, they have yet to arrive.  However, the trails yielded a great many birds and blooms to enjoy.

Ovenbirds, which breed in the preserve, were well represented with a singing male never out of earshot.  Despite this, they can be rather difficult to see, even from exposed perches.  Along the Paw Paw Trail a few Hermit Thrush revealed themselves amongst shadows in the holly trees with quiet “chuck” calls.  Slowly, they characteristically raised and lowered their tails.   As we hiked the Savage Trail back to the Post Oak Trail, a familiar, sweet warbling song with a slightly burry edge could be heard through the trees.  It was our first Summer Tanager of the year.   The single male was perched low in the understory in a flowering dogwood.  He remained perched for sometime and offered great looks.  After a few minutes, he flew away uttering his “picky-tuck” call.

The Scarlet Tanager with its black wings also breeds in the preserve, but has yet to make an appearance.  The Post Oak Trail hosted several singing Palm Warblers.  These habitual tail-bobbers are one of the earliest warbler migrants in the spring and a few have even wintered at Abbott’s Mill for the past two years.   Sassafras trees are currently in bloom and their yellow-green flower clusters coupled with the creamy white flowering dogwoods added another reminder of spring’s momentum.

We made our way back to the parking lot, but before we crossed the boardwalk, were heard a tail-bobbing Louisiana Waterthrush and a Northern Parula singing - two more for our warbler list.  Our tail-bobbing bird encounters were not yet finished as we spied a small shorebird flying over the pond in a strange arc-winged glide.  Upon landing, the Spotted Sandpiper worked the pond edge as he bounced his rump.  Just for good measure, we drove back to Abbott’s Mill via Griffith Lake and were rewarded with a Northern Rough-winged Swallow, fairly uncommon in the area.

The excitement of returning birds will continue to build over the next few weeks, making this one of my favorite times of the year.  If you’re interested, stop by Abbott’s Mill and the Milford Millponds Nature Preserve or join us on our weekly Wednesday walk.

Abbott’s Mill Nature Center Weekly Walk

Wednesdays, 8:00-9:30am

Free to the public