August 31, 2009
Last night, Mariton hosted a Sunset/Moonlight Kayak Trip on Lake Nockamixon. The conditions were perfect. High wispy clouds reflected the sunset. After the sun set, the moon was near the top of its arc and provided good light.
We saw several Great-blue Herons, an Osprey and a Belted Kingfisher. At dusk, we coasted by one heron that was only a few feet away. It had settled on a stump along the shore, and wasn't moving. Two different Screech Owls called. Bats skittered across the lake's surface in front of us as we paddled back to our take out spot. It was a marvelous night to be outdoors.
August 30, 2009
The Franklinia, Franklinia alatamaha, is still in bloom in our yard. I was reminded of Bartram's collection of this plant in 1765 not only when I recently visited Bartram's Garden in Philadelphia but also when I saw a sign along the riverwalk in Savannah, Georgia about John's and son William's plant explorations there. Georgia is the only place where Franklin tree seed was collected; all known plants in cultivation today are descendants of the Bartrams' collections.
Hog peanut (Amphicarpaea bracteata) is also now in bloom, here wrapped around some goldenrod.
Great blue lobelia (Lobelia siphilitica) is also in bloom in sunny wet meadows. This and the hog peanut are easily visible in the meadow behind the visitor center barn—some of the advantages of leaving a little area unmowed.
Indian grass (Sorghastrum nutans) is in bloom in our meadows. A good place to see it is in the meadows around the Chief's Grove.
One of my least-favorite plants is ragweed (here, Ambrosia trifida, giant ragweed). I am very allergic to the pollen which becomes airborne at this time of year. Even brushing the stems when mowing past it raises hives on my arms, and the pollen sends me into sneezing fits.
August 28, 2009
I found this milkweed tussock caterpillar (Euchaetes egle) on a butterfly weed in the garden. It had eaten much of the plant, but that is one of the reasons we grow native plants—to attract native animals. David L. Wagner writes in Caterpillars of Eastern North America that this caterpillar doesn't seem to compete with monarchs for milkweeds; monarchs appear to prefer younger plants and the milkweed tussock will eat plants that have already begun to senesce (474).
I find the dogwood sawfly
caterpillar less appealing. Their numbers explode and they defoliate much of the redosier dogwood in our garden. I knock them off with a sharp jet from the garden hose.
Fall webworms (Hyphantria cunea
) are also conspicuous right now, particularly on walnut trees around here but also fewer on cherry, persimmon, redbud, and others. Some trees host many nests and appear unattractive, though these caterpillars don't usually kill trees.
People often seem to think these are Eastern tent caterpillars (Malacosoma americanum) but they look totally different to me. Tent caterpillars are most visible in the spring, webworms in the fall. Tent caterpillars make their tents in the crotches of trees and are most conspicuous on members of the rose family: black cherry and apples. Fall webworms' tents are airy and at the tips of branches, and most noticeable on walnut trees.
August 27, 2009
When the days get short and the evening air whispers down from the north, I remember to purchase a federal Duck Stamp. This year's stamp features a pair of Long-tailed Ducks by artist Joshua Spies. They cost $15 and can be purchased at the post office. The U.S. Fish and Wildlife Service uses the proceeds from Duck Stamp sales to purchase wetlands for breeding waterfowl. To date, the USFWS has protected nearly 3 million acres of valuable waterfowl habitat.
When you purchase a stamp, you can pick up this year's guide to the migratory bird hunting seasons. Besides the season dates and bag limits, the guide has a report about goose populations from which I took the following information. In Pennsylvania, we actually host three different populations of Canada Geese during the fall and winter. The Atlantic Flyway Resident Population (RP) is the population that breeds throughout the state and into southern Ontario and Quebec, but also winters here. The spring breeding population in Pennsylvania was estimated to be 89,000 breeding pairs (and 290,000 geese total), about average. The population is stable (not growing or declining). Gosling production was below average this spring, but the fall population is expected to be similar to 2008, just with less young birds.
The Southern James Bay Population (SJBP) breeds in Nunavut and the Ontario Lowlands in Canada. Part of the SJBP will winter in the northwestern part of Pennsylvania, near Lake Erie.
The Atlantic Population (AP) breeds in northern Quebec along Hudson Bay and the Ungava Peninsula. Some of the AP winters locally in southeastern Pennsylvania. The AP reached the spring breeding grounds in very large numbers (176,000 breeding pairs), but the number of geese actually breeding was well below average. Nest surveys indicated low productivity. Still, the fall population is expected to be larger than last year, just with less juveniles in the population.
The Greater Snow Goose population is at a record high. Nearly 1.4 million birds staged in southern Quebec before heading to the breeding grounds in the Canadian Arctic. Nesting conditions were good. Clutch sizes were slightly below average, but nest success was above average. The fall population is expected to be above average this year.
Soon, it will be that magical time when great "V"s of geese will be honking overhead. Their arrival reminds us that winter is coming, and that a wild untamed land still exists somewhere far to our north.
August 27, 2009
Work on the nearby Harmonyville Road bridge is progressing; here's an update.
As of late July the macadam was being removed from the bridge revealing the wooden deck underneath. I enjoyed watching such a large machine being used so delicately to separate the asphalt from the wood.
Once the deck was off you can see why the bridge needed replacement. The I-beams have rusted and lost much of their strength.
The beams here are about to be removed. I missed this event while I was on vacation.
Now the span is gone and one of the bridge abutments is being removed. A coffer dam surrounds the site and a small pump runs continuously to keep the pit—well below the stream bed—dry. The water is pumped into a bladder to catch sediment and then it drains onto the adjacent land, not directly back into the stream.
All the work is being confined to a narrow right-of-way along the road, surrounded by silt fence. A biologist reviews the project at each step to make sure it isn't directly impacting wildlife. French Creek is rated an Exceptional Value stream so this project requires that the bridge builders take extra care.
August 24, 2009
I spent last week toes-in-sand in the low country of South Carolina, catching up on reading and relaxing with family.
A highlight of the week was witnessing the release of loggerhead turtles from a nest. Loggerhead turtles are threatened by habitat change, light pollution along the beaches where their young are hatched, and collisions with boat props. Volunteers work to mitigate the effects of these problems and monitor turtle populations.
The turtle patrol volunteers mark the location of nests and monitor the progress of hatching. Three days after the majority of hatchlings leave the nest they dig up the nest in the sand to count hatched eggshells, unhatched eggs, and live and dead turtle hatchlings. In a few cases there are several turtles that haven't made it out of the nest yet and they release them on top of the sand. It is important that the turtles still crawl to the ocean on their own power as that builds critical muscles needed for their survival at sea.
Normally the turtles crawl toward the moonlit glow of the ocean; light in houses along the beach leads them astray where they will die—so most communities practice "lights out" along the beach. The release the volunteers perform takes place in daylight so that they can track any turtles, so the hatchlings need to be directed toward the surf.
We were fortunate to see 24 turtle hatchlings scrambling from one nest to the beach. I should have used a faster shutter speed for photographs as the little ones moved a lot faster than I expected!
August 19, 2009
I've just finished Lenore Skenazy's book, Free Range Kids (Jossey & Bass, 2009). If Richard Louv's Last Child in the Woods directs how we (un)program our summer camps, this book provides additional inspiration for letting the kids choose their activities and play in a natural setting.
The subtitle of the book is "Giving Our Children the Freedom We Had Without Going Nuts with Worry." Of course the kids at camp are not our kids so they are still closely supervised, but we have tried to let the kids have the kind of playground interactions that are increasingly uncommon in today's over-scheduled and aptitude-tested kids. And we are using that most natural of playgrounds—the woods and meadows of Crow's Nest.
As a new parent I appreciate the guidance that Skenazy gives, the reality check that many common worries today are not supported by statistics. The book is entertaining and made good summer reading.
August 18, 2009
I was fortunate recently to be able to attend the biennial conference of the Mid-Atlantic Exotic Pest Plant Council, this year held in Johnstown, Pennsylvania.
The two days were full of rapid presentations about new research—some of which was contradictory, illustrating the complexity of the ecosystems and relationships within them.
Several of the presentations were about the interaction between deer and invasive plants: is there a synergy between them that allows invasive plants to be, well, invasive? What control methods are necessary to restore a site where a natural disturbance, such as a blowdown in the forest, has given light-seeking invasives a chance to become established: remove the invasive plants, fence out the deer, or both? (One study suggested that both are necessary, the other that fencing alone might work; both agreed that in the presence of high deer densities removing the existing invasive plants alone is unlikely to fill the site with a diversity of regenerating native trees.)
There were also updates on a naturally-occurring fungus that is killing invasive ailanthus trees, research on the density of ticks and presence of the Lyme-disease bacterium on sites invaded by Japanese barberry (more ticks and more Borrelia there), and research presented on an assessment of plants being evauluated for biofuels and their potential to escape into natural areas.
I'm still typing up my notes; it was an incredibly full and rewarding couple of days.
August 17, 2009
Yesterday, I checked trails early in the morning. A Red Fox loped across the South Fox Trail in front of me. At first it didn't seem aware of my presence, but I know better. Still, it wasn't in a hurry to exit the scene. Bob Koppenhaver has been monitoring game cameras at Mariton. The cameras have photographed at least one family of Red Foxes near the peak of the property. Bob has two notebooks of photos in the Nature Center that he updates periodically. Next time you visit, check them out. It gives one a whole new appreciation the different animals living at Mariton.
The Cooper's Hawk family that nests in the pines near the Nature Center can been seen flying around the yard almost every day. They are most active in the mornings until about 9:00 a.m. and then again from 5:00 p.m. on. But I have seen them at all times of the day. They were very noisy when the young first started flying. I am anthropomorphizing, but I imagine the conversation was something similar to when a youngster takes that first ride on a two-wheeler with the adult running along beside. It is fun to watch them as they fly along the tree line, or navigate amongst the trees just inside the forest. As the young learn the ropes, they are becoming less vocal.
Hummingbirds are extremely active at our feeders right now. Hummingbirds really need to consume calories right now. They are either in migration, or preparing for the journey. A hummingbird feeder can be emptied quickly at this time of the year. Maureen and I mix up a half gallon and keep it in the 'fridge'. That way it is ready to add whenever the feeders get low.
The various Goldenrods are really blooming in the meadows. There is still a good supply of Monarda, but it is starting to diminish. I didn't see many butterflies yesterday, but it was still early in the day, and there was a heavy dew on the meadow vegetation.
August 14, 2009
Rainfall has been spotty but abundant this August in much of Southeastern Pennsylvania. Some locales have been inundated with slow moving systems that dumped rain for hours. While others, just a few miles away, never received a drop. Mariton is in that category. Even though we missed some of the rain events that everyone else received, we have had our own isolated downpours.
It is adding up. So far this month, we have received over 8.5" of rain at Mariton. That is more than double the average for August (which is only half over).
The tropics have fortunately been quiet. We are already at the point of liquid soils; look at the Delaware River for confirmation. Continued heavy rains, combined with a tropical event, could spell big trouble for our area.