The Nature of Delaware

By: Jim White, Associate Director, Land and Biodiversity

Last week, while cleaning out the rafters of the Coverdale Farm Education Building, my co-worker, Dave Pro and I discovered a bat hibernating in the rafters.  The building is slated for extensive renovations so we had to disturb the bat from its winter rest and relocate it to another building.  Bats can be tricky to identify and I wondered what species we had found.  I knew that most species of bats that occur in our area usually migrate away from Delaware in winter because of the lack of suitable hibernating sites such as caves and mines.  However, at least two species are known to overwinter here – the Red Bat (Lasiurus borealis) and the Big Brown Bat (Eptesicus fuscus).  Our bat did not have the distinctive reddish fur of the Red Bat, so I assumed it was a Big Brown Bat.  Over the years I have learned, sometimes the hard way, that assuming things when trying to identify wildlife can result in misidentification.  So my wife Amy and I examined the bat closely, taking body, limb, and ear measurements and photographing things like the hairs on the feet, and structures of the ear and wings.  These are all traits that can be used to identify bats.  Although we found that the identification was not as easy and straightforward as we were hoping, we were able to confirm that our bat was indeed a Big Brown Bat.

Big Brown Bat by Jim White.

Big Brown Bats have adapted well to the presence of humans and use houses, barns, and other structures as communal summer roosts and nursery sites.  In winter, individual Big Brown Bats also use human structures for hibernation.  These sites, which are usually near their summer roosts, are warm enough to keep their bodies from freezing but cold enough to allow them to hibernate.  Attics and basements of heated structures often provide these conditions.  At these hibernation sites, Big Brown Bats enter into torpor as body temperature falls and metabolism is reduced.  However, this species is more tolerant of cold temperatures than most other bats and on unusually warm winter days it can become active and even fly to seek water.  In early spring the bats leave their hibernation sites to return to the communal roost sites to breed and spend the summer.

It is my hope that our bat will find its new hibernation site adequate, allowing him to survive the winter and rejoin his fellow bats in spring. 

On warm evenings from spring through fall, the Ashland Nature Center is a great place to watch Big Brown Bats as they swoop across the evening sky in search of their insect prey.

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By Jason Beale, Abbott’s Mill Nature Center Manager

The adult Naturalist Certification Class at Abbott’s Mill is focusing on Winter Tree and Shrub ID this month.  While it may seem strange to spend time studying deciduous (leaf-losing) woody plants during their dormancy, it helps sharpen your botany skills throughout the rest of the year.  The lack of leaves takes away obvious clues and demands that the naturalist stick to branching patterns, buds, leaf scars, and bark.

Black Cherry (left and right) and Red Maple (center) silhouettes

Branching patterns are probably the best starting place by classifying the tree as opposite (twigs and buds directly across from one another) or alternate (twigs and buds occurring in zig-zag pattern). 

Alternate branching pattern of Sassafras

Opposite branching trees and shrubs are represented by just a few species that can be remembered as: MADCap Buck, where M = maple, A = ash, D = dogwood, Cap = caprifolicaceae (the family composed of the honeysuckles, elderberries, and viburnums), and buck for the buckeye (aesculus spp). 

Opposite branching pattern of Flowering Dogwood. Note small buds near twig end also opposite.

 Buds can be categorized by number (single, paired, or clustered), shape (rounded, pointed, etc.), scales (single, double, overlapping, or no scales).  Below is a somewhat pointy bud cluster, typical of this southern red oak and other red oaks.  White oaks tend to have more rounded buds in their clusters.  Next is a tuliptree with its two-scaled “duck bill.” 

Clustered buds of Southern Red Oak

"Duckbill" of the Tulip Tree bud

 A Leaf Scar is where a leaf stem (petiole) was attached during the growing season.  They can be of a variety of shapes from circular, “U’s” or “V’s”, or unique.  The “Monkey Face” of the black walnut is a classic example.

"Monkey Face" of Black Walnut Leaf Scar

Bark is a useful for ID in any season.  Common descriptions include smooth (ex. holly and beech), checkered (persimmon), rectangular (white oak), furrowed (ash, hickory, and tuliptree), and an variety of others.  Black cherry bark is a good example of a mnemonic or memory-jogger.  The dark, flaky bark has been described as “Burnt Cornflakes”, “B” for black and “C” for cherry.

"Burnt Cornflakes" bark of a Black Cherry

Checkered bark of Persimmon

I would encourage you to look closer at the trees and shrubs around your residence.  Not only will your identification skills grow, but you may notice how birds like Brown Creepers investigate species with exfoliating or peeling bark for dormant insects and what tree species Yellow-bellied Sapsuckers favor for drilling their wells.

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by Derek Stoner, Education Program Assistant

An American Goldfinch perched on a sunflower stalk.

Wow! Is that an escaped canary outside?  No, it’s a male American Goldfinch, adding a splash of yellow to the drab winter landscape.  

Enticing birds and other wildlife to visit your backyard is rather simple: if you offer the food, they will come.   Native plantings will provide seeds and fruit for birds for much of the year, but in the depths of winter, a little supplemental feeding will bring them to your backyard where you can see them easily, and in tough times, can help them survive.

A bright male Purple Finch visits a black oil sunflower seed feeder.

A side-by-side comparison of male House(l) and Purple(r) Finches.

A female House Finch.

A Pine Siskin visits a feeder filled with nyjer.

A male Red-bellied Woodpecker visits a log packed with peanut butter/seed mix.

A female Northern Cardinal brightens up the backyard.

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By: Joe Sebastiani, Members Program Team Leader

The Delaware Nature Society Teen Naturalist Club met Sunday to participate in the annual Bombay Hook Christmas Bird Count.  Our group of 13 teenagers from Abbott’s Mill and Ashland Nature Centers were assigned specific tracts of the Little Creek Wildlife Management Area near Dover to survey for birds. 

Our first area was the impoundment along Port Mahon Road.  The task…walk the entire trail around the impoundment, which is about 3 miles long.  This trail is used by hunters to access distant duck blinds, and is walled-in by phragmites.  Despite this handicap, we saw lots of geese and gulls overhead, ducks on the partially frozen marsh, and sparrows in the reeds.

Teen Naturalists at the Little Creek Wildlife Management Area.

The highlight of our day was flushing a Short-eared Owl from the grasses and watching it fly in front of us.  We counted geese, tried to see half-hidden sparrows, followed Great Blue Herons, and tallied birds as we went.  What captured the minds and souls of the group, however, were dead things we found.  A dead Double-crested Cormorant was first.  It had been eaten by something, probably a River Otter, judging by the tracks and scat around the carcass.  Along Port Mahon Road, we found multiple deer that were dead.  Legs and odd bones were passes around, being closely examined by all.  At our next location, despite the fact that several Bald Eagles were flying around, the large dead fish we saw got the most hearty response from everyone.

One of six Bald Eagles that we counted on the Bombay Hook Christmas Bird Count.

A Teen Naturalist with his collection of spent shotgun shells, and the fish head we found.

The fish looked like some kind of Drum (or Coelacanth) dumped by someone in a field.  They probably made a good meal for the local eagles, however.  I am certain that jaw bones, teeth, and perhaps other parts of the skull went home with several of the kids.  In this field we also found more birds, such as Yellow-rumped Warblers, Eastern Towhee, and Ruby-crowned Kinglet, as well as a Bald Eagle nest with nothing in it. 

Unoccupied Bald Eagle nest.

By the end of the day, we found 39 species of birds for the Christmas Count, saw lots of otter tracks and scat, the eagle nest, and quite a few intriguing dead animals.  Whatever it takes to get kids interested in the outdoors!

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