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Archive for May, 2005

Creek Trail Reopens (if you have boots)

The beavers have stopped maintaining their dams in the area adjacent to the Creek Trail, and without constant maintenance they have begun to deteriorate. The water level has gone down, and the creek trail has reemerged, open but muddy.

We knew that beavers only stay in one section of creek as long as the habitat meets their needs, and they have probably moved to a different section to better access fresh, living trees. (They chewed a lot down, to access the upper branches they use as a winter food source and to create and maintain their dams.) Other trees died from having been flooded.

After two years, the boardwalks have risen out of the waters and been repaired (they were cabled in place when the waters rose to keep them from floating away). Lots of native vegetation is flourishing along the creek, and even one stand of invasive bamboo was killed by the flooding. We will miss the flooded habitat that was so good for wood ducks and muskrats, but we hope you will enjoy using the trail that forms the backbone of the preserve. Just be sure to wear boots–it’s still muddy there.

Inchworm Irruption

InchwormsYou can’t walk through the woods these days without seeing lots of inchworms, and what sounds like rain is actually their poppy-seed-like droppings hitting leaves on the ground.

Last year was the first year we experienced them in explosive numbers, a cyclical phenomenon known as a population irruption. Occassionally having a population explosion helps some prey species outnumber their predators, ensuring long-term survival. An irruption can also be an indicator of natural balances being disturbed.

Indeed, last year the woods were stripped of leaves in May, and it looked like winter all over again. But the trees leafed out again. This year the inchworms haven’t stripped the trees bare, yet. In this photo they were congregating all over a rotting tree stump.

The “inchworms” are likely fall and spring cankerworms (Alsophila pometaria and Paleacrita vernata), the larval form of species of moths. The youngsters feed on leaves, pupate in the ground, and adults emerge in fall or spring to lay eggs. The female adults of these native species are wingless, and climb back up the tree trunks to lay their eggs.

Thanks to Erich Estes for researching these insects last year.

The Forgotten Flower

TuliptreeThe tuliptree (Liriodendon tulipifera) has been blooming for a couple weeks now, but who’d have known? The flowers are found so high in this majestic tree that they are usually noticed only when they begin to fall down.

Honeybees, I’m sure, have noticed; it’s reputed to be a good source of nectar for them. Lots of other wildlife depends on the seeds when they form. The leaves are food for the caterpillars of tiger swallowtail butterflies.

Also called yellow poplar, tuliptree is in the Magnolia family, not related to other poplars. Straight and tall, tuliptree is an early successional species, one that gets established when a forest is young, and eventually gives way to oaks and others. Native Americans, I’ve read, made the light trunks into dugout canoes.

Primitive Plants

Scouring_rushWe know that ferns were around with the dinosaurs, based on fossil records, and are little changed today. Other plants, the so-called fern allies, also hail from that age and are botanically distinct from the flowering plants that evolved later.

Scouring-rush (Equisetum hymale) does not grow naturally at this preserve (though it can be found nearby at our Stone Hills Preserve). The common name is hyphenated above, implying that it is not a true rush, though perhaps it resembles one. Its leafless stems are filled with an abrasive silica–at one time they were used for scouring pots and pans. I planted some in my garden as a curiosity, a gift from a fellow gardner. She didn’t tell me how much it spreads! I wish I’d planted it in a sunken container to confine it. You’ve been warned.

Field_horsetailField horsetail (Equisetum arvense) is closely related, but is branched into fine leafless stems, making it look grassy or hairy. It is common in wet fields and roadside ditches, where it can be found at Crow’s Nest. These fern allies do not flower and set seed; like a fern they release single-celled spores that grow into a tiny organism called a gametophyte, where the reproductive processes analagous to a flower’s take place.

LycopodiumThere are a number of other fern allies, such as clubmoss and ground pine. This is common clubmoss (Lycopodium clavatum) whose evergreen stems and leaves brightened the monochrome late-winter woods.

The pinks have it

A couple of outstanding pink flowers have joined us in the last couple weeks–the pinxterbloom azalea (Rhododendron pericliminoides) and the pink lady’s slipper orchid (Cypriperdium acaule). By the way, I would be using italics for those botanic names, if I could do it in this software. I use the botanic names because they are more precise than the common names, which are variable and not universal.

Pinxterbloom is an azalea of the woods, and far more delicate in bloom than the shocking corals, oranges and fuschias of our garden varieties.

SlipperThe pink lady’s slipper orchid is not common in our woods–it may be a favorite with deer, and it does not reproduce rapidly. The botanic name derives from the Latin for “Venus’ foot,” according to the Audbon Field Guide to Wildflowers. Many orchids like this one grow in symbiosis with soil microbes, and so they don’t survive transplanting. Please leave them alone for others to enjoy!

Birding at Merrill Creek

On Tuesday (5/17), the Birding Group went to Merrill Creek Reservoir in Derby_prarie Harmony, New Jersey.  We scheduled the walk there to coincide with the spring bird banding as part of the MAPS.  Jim Mershon and Jane Bullis were in the middle of banding when we arrived and we were able to watch them band a number of birds.  This photo was taken by Virginia Derbyshire.  It is a prairie warbler, notice the chestnut markings on its back.  You can click on the photo for an enlargement.

Their banding day starts at 5:45 a.m. when they unfurl the mist nets.  (We arrived at 8:30.)  Then they check the nets every half hour.  Each captured bird is examined, and information concerning species, age, sex, etc is recorded on the data sheet.  They then put on tiny aluminum bands, numbered and recorded, before releasing them back to the wild.  The information is kept for their own records, but also sent to a national data base. 

Yellowthroat We were able to follow them as they checked the nets and watch them process the birds.  Jane and Jim were wonderful at answering questions and pointing out interesting facts – all while they were taking measurements and jotting down important information.  It was fascinating.  It isn’t often that you get to see warblers staying this still.  Besides this common yellowthroat (photo by Bill Roehrig) we watched them band magnolia warbler, house wren, and several catbirds.


Bill also took this photo of this genus Empidonax flycatcher.  This quote taken Unidentified_empid_1 directly from Roger Tory Peterson’s Eastern Birds:  "Five small flycatchers in our area share the characters of light eye-ring and 2 whitish wing bars.  When breeding, they are readily separated by voice, habitat, and way of nesting.  In migration they seldom sing, so we are forced to let most of them go simply as Empidonax flycatchers."  Even in the hand where one can measure wings, tail feathers, etc, they are difficult to identify, so Jim let this flycatcher loose without a band.

My thanks go out to Jim and Jane who were wonderful.  Linda Klopp sent me Merrill Creek’s banding dates, so I could schedule this walk to coincide with that.  Bill and Sharon Roerig scouted the area the day before, so we knew where to look for birds after we left the banding station.

Next Tuesday, we will be birding along the Delaware Canal down near Point Pleasant. 

Breakfast’s View

The “Breakfast with a View” program was a success. The food was great (pancakes cooked over an open fire, with lots of fruit and maple syrup), the folks friendly, and the view from the field above the Chief’s Grove beautiful. We also went on a long wildflower trek afterward, walking off the pancakes.

So you’d like to learn to draw?

In June we are offering a two-session mini-course at Crow’s Nest Preserve on drawing miniature landscapes with colored pencils. Local artist Eileen Rosen will teach the course, open to folks with all levels of experience. Ms. Rosen teaches courses at the Main Line Art Center, Chester Springs Art Studio, and Longwood Gardens, and we are thrilled to have her out to Crow’s Nest.

The first session will involve practicing techniqes using your personal photographs. The remaining time will be spent taking advantage of the preserve’s beauty. Class size is limited and instruction is non-judgemental and based on your needs.

Check out the event listings on the Crow’s Nest Events part of the website, or call 610-286-7955 for more information.

Bluebirds, too!

I can’t let fellow blogger Tim Burris get all the good bluebird box photos. (If you haven’t seen his excellent weblog, be sure to check it out at the “Mariton” part of the Natural Lands Trust website.) Here are some of our recently-hatched bluebirds, from one of the 14 boxes we maintain at Crow’s Nest Preserve.

Volunteers Daria Smith and Robert Bowar (with dogs Lakota and Chloe–leashed, of course) inspect and maintain the boxes each week and maintain records on the nesting and development. This information helps us make changes to the construction and orientation of the boxes to maximize success. (Thank you!)

We pair the boxes so that if one is occupied by swallows, for example, which will defend the other box from being occupied by others of its own species, that will leave one box free for bluebirds. They are located in grasslands or meadows, but not too far from hedgerows which allow the bluebirds to perch within sight of the box. (In one case, overhead electric wires seem to be their preferred perches.) Most of the poles have some sort of predator guard, so that our good intentions do not create a trap for the birds. Bluebird populations across the country are responding well to the creation of boxes that simulate the cavities in which they naturally nest, largely missing due to changes in land use.

Migratory Bird Census

This morning, we conducted Mariton’s 13th Annual Migratory Count.  We tallied 53 species and 229 individuals.  Fifty-three species is the fourth highest count (the average is 49 species).  The average number of individual birds for the 13 counts is 256 individuals. 

Mid-May is near the peak of migration, when one can see the most species.  Most birders are saying that the warbler migration has been slow this spring, and I would agree.  We counted 14 warbler species in 1999 (the year with the highest species count); this year we counted 10 warbler species. What is really noticeable is that the number of birds seems down, at least for some species.  On the bright side, we may be in for a stretched-out warbler migration.

Bird_count_51405_002 I would like to thank Bill Wallace, Virginia Derbyshire, Carole Mebus and Anne Hogenboom for volunteering their eyes, ears, and knowledge.  The census would not be as thorough without dedicated volunteers.  Plus, I really enjoy their company.

Here is a sampling of the some of the birds that we counted this morning (the complete count is posted in the Nature Center):  black-billed cuckoo, 6 black-throated blue warblers (that is a lot), Blackburnian warbler, chestnut-sided warbler, 16 ovenbirds, and 9 rose – breasted grosbeaks.  We spotted a great blue heron flying overhead, and yes we counted it.

We will be doing a Nesting Bird Census on June 4.  There probably won’t be as many species (although this year may be different), but it will certainly be interesting.  Bring your binoculars and help us count the birds! 


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