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Crow’s Nest: On my night table (or rather my coffee table)

By Daniel Barringer, Preserve Manager

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I have been enjoying the text and photographs of a recent book, The Living Landscape by Rick Darke and Doug Tallamy. I have enjoyed books by both authors—separately—before and think this new collaboration is just great. We have a copy of Rick Darke’s The American Woodland Garden (2002) and also Doug Tallamy’s Bringing Nature Home (2007). Both of these books celebrate the native landscape, both as it occurs in nature and how we can recreate it in our yards to benefit wildlife.

Rick Darke is a landscape consultant, lecturer, and photographer who has also been Curator of Plants at Longwood Gardens. Darke’s earlier book noted above is a study of patterns in nature and seasonal change and how we might apply these principals to our planted landscapes. This creates beautiful landscapes that are also functioning ecosystems. The second part of that book contains profiles of the many native plants we could be using—but historically were not as available in nurseries.

Dr. Tallamy is a professor in Entomology at University of Delaware (and member of Natural Lands Trust’s Board of Trustees). His 2007 book turned horticulture on its head: up until then plant lovers would seek out ornamental plants—often non-native—that were least prone to insect damage so as to avoid tattered and chewed leaves. Tallamy points out that insects are the base of the food web and that if we want to attract and support wildlife we need to plant and grow those species that support the insects that feed the rest of the wildlife. There’s no point planting something that attracts butterflies with its flowers unless we also have something to feed their young: caterpillars eating leaves. And if we want to attract birds to the garden, it isn’t enough to plant something that seasonally might have fruit that they eat—we need to grow plants which support the insects that feed them during their growing and mating seasons. So plant a diversity of native plants to support those herbivores, Tallamy writes, so that damage on any one species isn’t so noticeable.

Darke and Tallamy had already contributed to a renaissance in native landscaping. Compare the availability of native plants in garden centers today with just ten to fifteen years ago.

Honestly, almost any book on landscape design will have parts that interest me. But when the focus is on native plants and naturalistic plantings, all of it interests me. The Living Landscape covers communities—what plants tend to grow in association with each other, as well as landscape layers, timing and opportunity. It is filled with photos that inspire and stories that explain why these landscape choices are important. A guide in the back details includes the ecological and landscape functions for many native species.

Over the years I enjoyed landscaping with native plants around the visitor center barn and tenant house at Crow’s Nest. There were successes and failures, and some of my first choice native plants were not widely available at the time I started planting. As I have recently moved to another home on the preserve that is largely a blank slate, I will turn to this book to inform my planting choices. And as the preserve itself is a managed landscape (but not landscaped) this book helps show what natural areas should look like—with low-maintenance transitions from meadow to woods, free from invasive plants and supporting a diversity of wildlife.

I’m also looking forward to attending a lecture by Rick Darke and Doug Tallamy, The Living Landscape Lecture and Book Signing on March 12 at the Academy of Natural Sciences in Philadelphia. Jointly sponsored by the Academy and Natural Lands Trust the evening promises to be entertaining. I’ve heard each of these writers speak individually and am excited to hear them lecture together.

Crow’s Nest: On thick ice…

By Daniel Barringer, Preserve Manager

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Yes, that’s the creek the kids are playing on. Not in, but on. Good times.

Enjoy Winter! Black Bears

by Tim Burris, Preserve Manager

BEAR TRACKS

Black Bears (Ursus americanus) have a really interesting strategy for dealing with the winter.  Their winter sleep is not considered true hibernation by some scientists, but it is truly remarkable.  If you remember from an earlier post, groundhogs are considered true hibernators because they radically lower their metabolism (body temperature, heart rate, and respiration) for extended periods.  Bears by contrast, lower these functions but not enough to drastically lower their energy needs.  This fact makes their winter sleep even more amazing.

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Like Groundhogs and Deer, black bears binge eat in the fall.  Bears can increase their weight substantially (40%) before denning.  Their winter layer of fat will be several inches thick and provides insulation as well as nourishment.  The decision to den is closely related to food availability, or more accurately calories.  Bears will generally den when the calories expended to find food exceeds the calories gathered.  Females usually den in November.  Males can stay active through December if food is abundant and not covered by snow.

Because they aren’t true hibernators, bears burn calories at basically the same rate as we would while asleep.  This is where things get pretty amazing.  Burning calories produces by-products, in particular toxic urea.  We rid our bodies of these toxins when we urinate.  Bears, however, don’t urinate or defecate during their winter sleep.  (You’ll recall that even groundhogs rise from their hibernation periodically to void waste products.)  Bears have the amazing ability to recycle urea back into proteins.  This process allows them to maintain muscle mass and avoid urea toxicity.

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(Bear cub photo by Carole Mebus)

Bears also have their babies during the winter during pseudo-hibernation.  (In Pennsylvania, females generally become sexually mature in their second spring, and can have young every two years.)  Bears mate in June and July, but the fertilized embryo survives in a suspended state for several months until the female dens.  Then it becomes implanted on the uterus and begins to develop.  This delayed implantation is a safety measure in case a female isn’t able to find enough food in fall.  Implantation will only occur if the mother has built up enough resources for bearing cub(s).  Young are born only 7 weeks later in early January, while the mother is still in the den. So, during her deep sleep a pregnant bear has her babies and begins nursing, all nourished by just her fat reserves.  Remember during this time she doesn’t eat or drink, and she doesn’t go to the bathroom.  Oh, and bears don’t get osteoporosis even though huge amounts of calcium are being utilized to develop embryos, produce milk, and replenish the mother’s own bones.  (Think how unlocking those secrets could impact traveling in outer space!)

Now let’s talk about denning.  Bears don’t need to sleep in a cave or hollow log.  Because of their insulating fat and fur, they can sleep out on the ground all winter (although females usually den in protected shelters).  Bears den in a variety of places including brush piles, or next to a log.  Because bears are in a deep sleep, they can wake up fairly quickly.  They will be groggy at first, but they can get up and run if the need arises.  So, if they are displaced from a den site, they can find a new area, make a bed from leaves and grass, and continue their sleep.

If you find all of this fascinating, I invite you to join us at Mariton on Saturday, February 28 at 7:30 p.m.  I will be showing the movie On the Trail of Pennsylvania’s Black Bears.  This documentary covers the seasons of a Black Bear’s life with lots of interesting information and amazing footage.

Crow’s Nest in the snow

By Daniel Barringer, Preserve Manager

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We’ve had lots of little snows here. Not enough for cross country skiing, but enough to do some shoveling and occasional plowing. Here’s the old farm lane at Crow’s Nest just before plowing.

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And I like this photo of boulders in the woods at Crow’s Nest; they look like they’re sleeping with blankets of snow pulled up over them.

Green Hills: Nomination, Accepted

By Daniel Barringer, Preserve Manager

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Our nomination of the large red maple (Acer rubrum) at Green Hills Preserve to the register of Big Trees of Pennsylvania has come through. This list is dynamic as these trees are themselves growing, but I can say that this tree is currently one of the largest red maples in the Commonwealth.

Our tree has a 188″ trunk circumference (about five feet in diameter!) and is about 75 feet tall with a crown spread of 95′. These were the figures we submitted last year based on measurements in the field and corroborated by using LIDAR imagery.

I certainly recommend a visit to see this grand tree in person, but I’ll note that we don’t do winter maintenance of the parking area at Green Hills. Today it’s accessible, tomorrow, who knows? It would be nice finally to have some significant snow but on the other hand I’m kind of ready for spring.

 

Crow’s Nest: Sometimes we nail it.

By Daniel Barringer, Preserve Manager

We have a hazard tree management program on our preserves. It’s not something we talk about much, but just something that we do as part of our routine land management.

Twice a year we survey the trees near targets such as buildings, wires and roads. Trees with defects are entered into a database that we forward to Tom Kershner, our Arborist, who oversees the program. We monitor these trees until they are rated high enough that we think they need to be removed or pruned.

Every tree dies someday, that’s reality. We would like to manage how and when trees along roads fall. One cannot eliminate risk, only manage it. Sometimes a tree with no outward defect fails, but often there are signs we look for to evaluate a tree’s decline. Our preserve managers have received training on evaluating tree health and proper chainsaw operation for felling trees.

Sometimes it’s obvious why a tree is on the list. If it’s dead and near a target, it needs to be removed. Sometimes woodpeckers excavate the trunk, indicating insect damage and likely rot. And sometimes a tree falls due to “soil failure,” where saturated soils can’t hold the roots of a tree with a tall crown. Trees near roads suffer many stresses: physical damage from cars or road maintenance, road salt, reflected heat from the road surface, nails from boundary signs, and their roots don’t typically grow well under the pavement—a surface that is impervious to water and deprives roots of the oxygen they need.

The red maple below didn’t look like an imminent hazard—and it wasn’t. But it had experienced some storm damage from ice accumulation—small broken limbs still dangling above, but not big enough themselves to be a hazard. And it had lost a couple branches entirely but the bark had failed to grow over the holes leaving open cavities. It wasn’t a huge tree, and it was tempting to put off any management until the tree was larger and really looked like a hazard. After all, as I’ve said before, I prefer my trees standing. But this one really wasn’t thriving and would only be more difficult to remove when larger.

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So although I had no idea this tree was so hollow I wasn’t surprised to find that it was. There are tests you can do, and even tapping the trunk lightly can sometimes reveal that there is a cavity inside. I am glad I made the call that this one should go. By the way, a hollow tree is also more difficult to safely take down because it lacks much of the material used to create a hinge for the felling.

There are some good books out there for learning about tree defects. Here are three I like:

Tree Decay: An Expanded Concept by Alex Shigo, USDA Forest Service Bulletin 419, April 1979.

The Body Language of Trees: A Handbook for Failure Analysis by Claus Mattheck and Helge Breloer, translated by Robert Strouts and edited by David Lonsdale, United Kingdom Stationary Office, 1998.

Evaluation of Hazard Trees in Urban Areas by Nelda P. Matheny and James R. Clark, International Society of Arboriculture, 1994.

 

Mariton: Turkey in the Snow

by Tim Burris, Preserve Manager

Turkeys under the feeder

I am seeing a lot of Turkeys on this side of the hill lately.  I think they are taking advantage of the southern exposure and our neighbors’ bird feeders.  They have definitely been visiting the bird blind and our feeders.  The other day I was checking trails and found the tracks pictured below.  There had been an early skiff of snow, and sun was now bright.  The tracks were so fresh, that I knew I would cross paths with the turkeys.  I had the camera ready, but the snow was too crunchy.  All that I saw of the flock was individuals dashing through the brush.

Turkey tracks

 

Crow’s Nest: A bit of color

By Daniel Barringer, Preserve Manager

Right about now you probably would like to see some color, some reminder that spring and summer will come. Here you go.

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Crow’s Nest: Parents’ benches in play area

By Daniel Barringer, Preserve Manager

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On a couple of the worst weather days this winter Aubrey and Cody built several more Leopold benches for the Crow’s Nest Preserve. The latest ones are strategically placed for the comfort of parents or nature club counselors who are supervising unstructured play time in the woods.

I still remember my childhood friend’s dad who took us to a park where we re-routed the stream and climbed trees while he read the newspaper with one eye on us. We took it for granted at the time, but he really knew what he was doing.

I’d like to revisit that park today. I’ll bet it’s tiny compared to my memory of it. It doesn’t take much physical space to let a kid roam, just a little patch of nature and the space that is created by giving permission to play.

Crow’s Nest: On thin ice…

By Daniel Barringer, Preserve Manager

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At our nature club programs this week the sledding slopes were wearing thin. But that doesn’t mean we didn’t find places to slip and slide.

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With a running start, how far could you slide on the ice?

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Sometimes aerodynamics helps.

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And then we threw clumps of snow off the bridge to watch them burst on the ice below.

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