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Archive for June, 2007

Crow’s Nest: Wildlife happenings

GraytreefrogLast night this gray treefrog (Hyla versicolor) came to visit our water garden and serenade us during the rainstorm. We have a barrel full of water and plants with a small fountain next to the front door that refreshes—if only mentally—during the hottest of days.

We frequently hear gray treefrogs, usually high in the trees, but I’d never seen one in person before. Their call involves a little ventriloquism—it’s hard to find the source.

In the woods at the bend in Piersol Road there is a red tail hawk nest with a juvenile calling—pretty much every time I pass by.

Mariton: Io Moth

MothwitheyesmaritonwingsclosedLast week, during Day Camp, we came across this Io Moth.  (I didn’t know what it was at the time.)  It was bright yellow, and hiding down in the vegetation.  I kneeled down and held back some of the leaves, so that Carole could get a photo for later identification.

Mothwitheyesmariton2The kids pressed against my shoulders to get a better view.  When the moth spread its hind wings to reveal these "eye spots", the kids fell over each other, while jumping back in surprise.  We had touched on the purpose of eye spots as a defense mechanism earlier in the week.  They tried to deny that they were frightened, but they had all jumped back en masse.  I think they now understand the benefits of eye spots.  (Photos by Carole Mebus.)

Mariton: Road Closure Update

I just received a call from our neighbor, and the tree work had to be rescheduled.  So, you can disregard the post earlier about Sunnyside Road being closed on Wednesday morning.  I am sorry for any inconvenience.

Crow’s Nest: Getting ready for camp

Natural Lands Trust building stewardship staff: Bob, Steve, Luke and Scott took a short break from restoration projects to create an environment in the upstairs of the barn for camp. I think they have outdone themselves this year.

Campsetup07I don’t want to give away too much—and the kids will do all of the finishing work—but I can tell you that inside the barn the kids will be acting out the water cycle.

The guys have built an “evapo-transpirator” that will lift the kids like molecules of water, and the kids will drift across the barn like clouds and precipitate to the ground by ingenious means. There is also under construction a beaver dam and lodge and a house with septic system. Campers will add the critters that reside in these habitats.

We’re looking forward to a great program—which, regretfully, is full.

Mariton: Sunnyside Road to be Closed

On Wednesday, June 27th the road to Mariton will be closed.  One of our neighbors is having some tree work done between 8:00 a.m. and 1:00 p.m.  The road may not be closed the entire time, but I recommend that you plan any visits to the Sanctuary around this work.  Since Mariton is located near the end of a Dead End road, access can sometimes be affected by storms and road work.

Mariton: Butterfly Cenus

Butterfly_cnt_62307_001We had a great morning for a Butterfly Count at Mariton.  The weather was wonderful, the butterflies were cooperative, and we had six counters that all contributed skills.  We ended up with 22 species, which ties our highest counts.  We counted 216 individuals, which is in the middle of past counts.  As usual, Cabbage Whites (64) and Great Spangled Fritillaries (34) were the most abundant species. 

RedadmiralonmilkweedWe had large numbers of Red Admirals (12), Hoary-edged Skippers (11) and American Painted Ladies (6).  Thanks to the folks that came on the count.  I felt Spicebush Swalllowtails were down a little.  (The Red Admiral photo by Carole Mebus.)

Crow’s Nest: Rambling the preserve

This week while visiting the preserve students from Lansdowne Friends School commented to me about small birds harassing larger ones—crows harrying hawks, sparrows hounding crows. Normally the larger bird species could be a predator of the smaller one, or a threat to their eggs or young. It occurs to me that this harassment by smaller birds is not an occasional behavior; you can see it almost every day at the preserve.

At this season the deer are browsing hard on ragweed and Oriental bittersweet (but not hard enough to prevent it from climbing up trees). I saw turkeys yesterday and found a place in the woods where they had turned over the leaf litter on the ground of the forest searching for insects or seeds.

PersimmonflowerWe also found these flower parts on the forest floor and were mystified. They are from persimmon trees (Diospyros virginiana)—a species that I can more easily identify by its alligator-skin mature bark than by anything else. I have a small one I planted in the yard that also flowered for the first time this year. Persimmon fruit is an important wildlife species and is also spread by the mammals who eat the fruit.

David Harper’s class from University of Pennsylvania also came to the preserve this weekend for a walk and talk about land management and conservation. Their questions, as always, provoke thought: why do we make the management choices we do? I think it’s important that we question ourselves so that we can approach our work thoughtfully.

Crow’s Nest: Your help wanted

CaterpillarI’d like your help identifying this beautiful caterpillar—found on our persimmon tree this week. If you know what it is, please call me at 610-286-7955 or email at dbarringer (at) natlands (dot) org. Thank you!

Crow’s Nest: The Iron Tour

I am enjoying this afternoon watching bicycle riders pass by the preserve on the roads on their way to complete the Iron Tour, an event organized by French and Pickering Creeks Conservation Trust.

It’s not exactly like having a seat at the Manyunk Wall, but it’s fun watching these serious riders whizz by. The event has 100, 75, 50, and 25 mile courses around these hills as well as 15 and 4 mile courses—so riders of all abilities can participate.

The annual Iron Tour is gaining a good reputation with the cycling crowd, as it passes through scenic country roads past protected lands, including those of Natural Lands Trust, French & Pickering Creeks Conservation Trust, and others.

Mariton: Day Camp – Thursday

DamselflyandkatydidToday, we talked about predators of insects.  After the kids listed all the insect eaters that they could think of, we took a walk.  Right out the door, we watched a downy woodpecker foraging for insects on a dead branch.  We heard lots of insect-eating birds like scarlet tanagers and veerys.  We stopped at the bird blind to watch birds and chipmunks (eating seeds).  Inside the blind, we found a red bat snoozing on a rafter.  Here is an insect-eating damselfly that we found on our walk.  (Can you find the other insect in this photo?)

This morning, we also spent time talking about compound insect eyes and vision.  Humans can actually see each ommatidium in insects, with a little magnification.  (The ommatidium is basically the visual gathering component of an insect eye.)  We see them easily, because they are much larger in insects, than the photoreceptors found in mammals and other vertebrates.  Because of the larger size, there are less per square millimeter.  Hence the image an insect sees is likely of lower resolution.

LectureinwoodsLectureinwoods9pixThis is a complex concept for adults to understand, so I wondered if the kids would get it.  At the end of the morning, I asked them to draw an object as they see it, and then as they imagined an insect might see it.  Some kids drew multiple images of an object.  Science fiction movies often portray "bug vision" in this way; and the word "compound eye" lends acceptance to this thinking.  But about half the kids drew their bug’s eye view fuzzy, and a little outside of the lines.  Our photographer, Carole Mebus, worked up this great rendition on the computer.  Same photo; she just pixalated the one on the right.  Click on the photo to enlarge it, and then move away and toward your monitor to see how the clarity changes.  (Photos by Carole Mebus.)

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