Signs of Summer 11: Monarchs and Milkweed

Female Monarch (photo by K.D.Harrelson (Wikimedia Commons))

Female Monarch (photo by K.D.Harrelson (Wikimedia Commons))

Over the past few years I have written three or four essays about monarch butterflies and emphasized their dependence upon milkweed plants. The various species of milkweed that grow across North America are the only plants on which the monarch can lay its eggs. The chemicals (the “cardenolides”) that the monarch caterpillar accumulates from feeding on the milkweed make it and also the adult butterfly it will turn into poisonous to, and thus protected from, most potential vertebrate predators. Monarch populations have declined greatly over the past decade. Human impacts on old field and edge ecosystems where milkweed can flourish have greatly reduced the distribution of this important plant and are at least one of the factors that is causing the observed population declines of this beautiful butterfly.

Just outside my back room where my writing desk is located there is a stand of fifteen very hearty milkweed plants. They started flowering in early July and were covered with honey bees, bumble bees, tiger swallowtail butterflies, and fritillary butterflies for several weeks. Through most of July, though, I did not see any monarchs, and the milkweed leaves showed no evidence of any caterpillar predation.

Doc Mueller is a colleague at Penn State New Kensington. Last year Doc and his wife Linda raised some painted lady butterflies from caterpillars, and this year they have decided to raise monarchs. Last fall I gave Doc some milkweed seed pods which he stored out in his garage all winter to cold stratify. He planted the milkweed seeds in flower pots this spring and they germinated beautifully (something I have never accomplished. My thumb is no shade of green at all!). He put the potted milkweed shoots in the entryway to his house and then ordered some monarch caterpillars from an on-line biological supply company. The caterpillars arrived and ravenously took to the milkweed shredding leaf after leaf turning them into caterpillar biomass and a prodigious pile of black fecal pellets.

Photo by D. Sillman

Photo by D. Sillman

Doc and Linda quickly recognized that they had more caterpillars than their milkweed would support, so they gave me eight caterpillars to put out on my plants. I was concerned about matching up these tiny caterpillars (which were probably in the third or maybe fourth stages of the five instar series they would have to develop through) to the great, thick leaves of my milkweed plants, but as you can see from the picture to the left where there is a will (or a hunger) there is a way! The leaves on my plants slowly took on the characteristic ragged edges and gouged out tips and sides that are hallmarks of monarch inhabited milkweed.

I don’t know how many of my eight caterpillars will make it to adulthood. In the wild some 90% of the caterpillars succumb to disease, invertebrate predators, parasites, or parasitoids. The dense populations of birds in my yard are also a worry: as far as I know none of them have every experienced eating monarch caterpillars, and they may just try one or two before they realized their toxicity! I don’t have nearly enough caterpillars, though, to teach all of these birds a culinary lesson!

I looked over my milkweed plants carefully this morning. There was extensive leaf damage from feeding caterpillars but no visible cocoons. A number of the lower leaves, though, are curled up into tight clumps that would be just the place to make a very protected cocoon! I did see my first monarch of the summer fluttering around the side of the house. I can’t say for sure that it is one of “my” monarchs, but why not?

I heard from Doc this past weekend: four of his caterpillars made cocoons and that three of them have already emerged as butterflies! He moved the milkweed pots outside so that the butterflies could stretch their wings and fly away. Although it is hard to watch them leave after so many weeks of careful watching, it was time to let them choose to go north or south.

Photo by D. Sillman

Photo by D. Sillman

Pennsylvania is just one of stops on the seasonal North American northward surge and southward retreat of monarchs. Some of the adult monarchs that hatch here will continue on north to lay more eggs on the later growing milkweed in New York and New England. Other monarchs that mature here will turn around and begin the long journey back south. They will lay their eggs on some late season, southern milkweed and then that next batch of adults (or maybe the next cohort that comes after that) will head to the coniferous forests in the mountains of the Mexican states of Michoacán and Mexico where they will overwinter. Maria Franco, one of our Penn State colleagues, grew up in a town close to these butterfly forests. She remembers as a child seeing clouds of monarchs flying past. At the time, though, she was not aware of their communal overwintering site up in the nearby mountains. One of these Januaries Deborah and I are going with Maria and her husband Javier (also a Penn State colleague) to see these great forests covered with millions and millions of monarchs!

I would encourage everyone to either plant some milkweed somewhere on your property or at least tolerate the milkweed that is growing there voluntarily. The loss of the seasonally growing strata of milkweed across North America is cutting great holes in the support system for the monarchs and could lead to their extinction. Barbara Kingsolver wrote about the plight of the monarchs and their fractured migratory pathways in her recent novel “Flight Behavior.” I recommend it to all of you as not only an excellent read but also a very solid piece of speculative science.

Happy summer, everyone!

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Signs of Summer 10: Neighborhood Walk (part 2), Trees and Animals

Photo by D. Sillman

Photo by D. Sillman

(continuing last week’s discussion of our nature walk in the suburbs):

Around many of the houses up and down these suburban streets are a variety of primarily solitary trees. Houses of styles that were built in the 1950’s or 1960’s have significantly larger trees than those houses of styles built in the 1970’s. There were, however, very few “old” trees (trees that were of obviously greater age than the surrounding houses) anywhere in the neighborhood. My assumption is that when this housing plan was laid out there were either very few trees of great age (this may have been part of a set of old farm fields) or the larger, older trees that were here were cut down to make positioning of the streets and houses easier. The most common trees in the yards are Norway maples, blue spruces, Norway spruces, and silver and sugar maples. The spruces are of substantial sizes (more than a foot in diameter and 40 to 50 feet tall) and have broad growth forms with little branch shading or limb pruning. Only in a very few cases, though, are any of the trees in branch contact with each other. For the most part, the trees are widely separated and quite isolated. Yellow birch, European white birch, yellow poplar, cherry, and crab apple trees are also growing in some of these yards along with a variety of shrubs including rhododendron, azalea, burning bush, yew, privet, Rose of Sharon, forsythia, lilac, and a variety of forms of arbor vitae.

Photo by D. Sillman

Photo by D. Sillman

Now without getting too preachy or picky about the subject, it is important to consider the idea of “native” vs. “non-native” plants with regard to these tree and shrub species. The three most abundant trees are introduced, exotic species. The Norway maple is native to eastern and central Europe and has been, primarily because of its tolerance of a wide range of site conditions, extensively planted throughout the eastern United States. Its attractive shape and dark, reddish colored leaves also make it a striking addition to many landscaping schemes. The Norway maple, though, because of its prodigious production of seed and its tendency to form dense thicket masses in untended ecosystems, is classified by the National Park Service as an alien, invasive plant that should be avoided. The escape of this species into the wild has done a great deal of damage to native plants throughout the eastern United States. The Norway spruce (which is native to northern Europe) and the blue spruce (which is native to western North America) have also both been widely planted as ornamental trees throughout the United States. Their respective reproductive and growth patterns do not generate invasive or destructive responses in unmanaged ecosystems, although both have “escaped” extensively from landscaped systems into surrounding forests and both have, undoubtedly, had some negative impacts on competing, native tree species.

Photo by D. Sillman

Photo by D. Sillman

Rhododendron, arbor vitae, and some (but not all) of the azalea types are native plants in our region. Burning bush (which comes from northeast Asia), privet (of which there is a European form, a Japanese form, and a Chinese form), Rose of Sharon (which comes from southeast Europe and southwest Asia), lilac (which comes from Europe and Asia), forsythia (Pictured to the left) (which comes primarily from eastern Asia), and yew (which comes from England) are all exotic, introduced shrubs. Of these plants only the lilac and the English yew are classified as “non-invasive,” although both are recognized as having frequently “escaped” into surrounding ecosystems. The other species (burning bush, privet, Rose of Sharon, and forsythia) have not only widely escaped but also have caused, according to the U.  S. Forest Service, via their dense and destructive growth patterns, widespread declines in many native plant species.

There were a few flower beds observed during our walk. Roses (a very old domesticated flower which probably originated in the Middle East thousands of years ago) were quite abundant, as were crocuses, daffodils, and tulips (all of which are from southern Europe, North Africa, and Asia).

Photo by D. Sillman

Photo by D. Sillman

We saw three gray squirrels (a native North America species!) on our hour walk through the neighborhood. Each squirrel was seen running casually across an open area, moving from one tree’s cover to another. The squirrels seemed very tame and unconcerned with nearby people or vehicles. My guess is that the town has a well obeyed leash law for dogs, and that these squirrels have few potential predators with which to concern themselves.
We saw three dogs being walked on leashes. These animals greeted us in calm, dog-like fashions and wagged their tails at us as we passed. We also saw three yard dogs who expressed their extreme dislike of our being anywhere near their houses. Two of the yard dogs had receivers on their collars and were “contained” by electronic “invisible” fences around their yard peripheries. Both of these dogs, in very disconcerting fashions, rushed up to the sidewalk edges of their electronic borders barking wildly as we went by. The third yard dog was restrained by a more conventional (and visible) fence and barked more sedately as we went by. The restraint and containment of these dogs greatly reduces their potential influences on the neighborhood ecosystem.

Photo by M. Hamilton

Photo by M. Hamilton

We only saw one cat on our morning walk (pictured to the left are my daughter’s cats (Binx and Mora) whom I have been trying to include in a blog for some time now!). The neighborhood cat was sitting on the outside sill of her front window watching the events of her neighborhood with an inscrutable calm. We, of course, as only cat lovers can do, made fools of ourselves waving at her and calling to her as we passed. She responded with a tired blink.

There are 38 million households in the United States that have cats as pets (a total of 60 million individual cats). There are additional 60 to 70 million cats in the United States that are classified as feral (a topic I discussed in a blog last Fall). These feral cats live not only in the countryside but also in urban areas (in alleys and abandoned buildings) and in suburban neighborhoods like this one. They live in groups called “colonies” and by maintaining primarily nocturnal activities often successfully avoid both detection and capture. Cats eat 5 to 8% of their body weight daily (a female feeding kittens (which is a common condition in the feral cat colony) eats 20% of her body weight daily). These feral cats, along with free-ranging house cats, kill millions of birds and small mammals (rodents, rabbits, squirrels, chipmunks, etc.) each year in order to survive. Their impacts on the bird and mammal populations of our ecosystems are substantial. Cats are not native to North America. They were brought here from Europe and Asia and, based on the impacts they have on our native fauna, they should be classified as an alien invasive species!

Photo by D. Sillman

Photo by D. Sillman

Birds observed on our walk included English sparrows, European starlings (both of which are alien invasive species), common grackles (pictured to the left), American robins, and mourning doves. Notably absent were northern cardinals, song sparrows, chipping sparrows, house finches, blue jays, chickadees, and dark eyed juncos (birds that I know to be quite abundant in the area). No bird feeders or bird baths were observed, but we assume that there were some in the back yards of at least some of the houses. In the United States, according to the Ecological Society of America, 43% of people feed birds. Bird feeders have many positive and also a few negative impacts on wild bird populations. Obviously, by providing a reliable and abundant source of high quality food, birds are better able to reproduce successfully when there are feeders in their home ranges. But, crowding of birds at a feeder can accelerate the spread of some diseases and also increase the presence and activities of predators (including hawks, owls, and house cats).

Photo by D. Sillman

Photo by D. Sillman

Robins, of course, would not come to a feeder to eat seed. The robins we observed were busy searching through the expanses of lawns looking for any signs of earthworms. Interestingly, although the robins are a native species, the earthworms for which they are searching are not. These large, “lumbricid” worms (of which the “nightcrawler” is an excellent example) are familiar to anyone who has ever gone fishing or gone out for a walk on a damp, cool morning. These worms are very important to the diet of robins, but they are, in fact, exotic species. European settlers brought these earthworms with them either intentionally or, more likely, inadvertently in pots and bags of soil around roots of transplanted trees and other plants or in association with some of their agricultural animals, tools, or other materials. The staggering numbers and broad ubiquity of distribution of these European earthworm species all across North America are amazing. It is hard to believe that a group of organisms this common and this widely occurring is not native. We often think of the benefits to soil structure and rates of leaf litter decomposition associated with these worms, but there may also be a downside to their activities. Their destruction of the covering layer of leaf litter may have caused the decline and or extinction of many litter dwelling insects and may have irrevocably altered the energy dynamics of forest litter decomposition and nutrient cycling. That these European earthworms are quite abundant in the soil covered by European grass species that is shaded by European trees, though, has some very logical symmetry to it.

The nature of the dominant neighborhood plants generates very little in the way of non-birdfeeder food materials. Also, the almost total lack of any natural, surface water sources greatly inhibits the establishment of significant populations of wild birds. The presence of the Norway and blue spruces and the English yews generates some protective nesting habitats for a wide range of bird and small mammal species, but the wide spacing between these trees and shrubs and the close proximity of any number of noisy and potentially disrupting human foci would be expected to reduce the quality of these nesting habitats. I hope that there are significant numbers of feeders and bird baths in the hidden areas of the back yards although, the very small numbers and low diversity of observed birds and mammals would suggest otherwise.

So, this is suburbia. A hodge-podge ecosystem of mostly alien invasive plants kept in an extremely unstable configuration via the near constant investment of resources and energy. We could construct a much better, more productive and more stable suburban ecosystem, I am sure, if we only would give it a little thought. Rising fuel costs and declining oil resources will probably trigger some of these changes over the coming decades. I will keep you posted!

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Signs of Summer 9: Neighborhood Walk (part 1), Lawns

Photo by Fgrammen, Wikipedia Commons

Photo by Fgrammen, Wikipedia Commons

Nature walks can be taken in the woods, across open meadows, or along river or lake or ocean shorelines. You can also take nature walks along suburban streets. Deborah and I took a stroll around a nearby suburban neighborhood to see what the ecosystem was like.

The most prominent features of this neighborhood, as would be true of almost any randomly chosen section of suburbia, were the lawns. Each lot was about 20 to 25% occupied by a house, garage, and driveway leaving the remaining 75 to 80% of the area for grass. Most of the lawns were closely trimmed and densely vegetated with tightly packed grass plants. Fescue and bluegrass were the dominant grasses. Most of the lawns were extremely controlled monocultures (as pictured below): no clover, no dandelions, no ground ivy, and no “weeds” of any kind. Occasionally, we passed a yard that had escaped from this controlled state, and it had abundant dandelions, ground ivy, plantain, and dozens of other low growing green plants filling in the spaces around the still thriving grass plants (picture further down the page … actually that’s a picture of my lawn!).

Photo by D. Sillman

Photo by D. Sillman

A monoculture of any kind be it lawn or cornfield is an unstable ecosystem. Successional forces and waves of opportunistic, invading species (collectively referred to as “weeds”) exert immense pressures on the system. These forces would very quickly change a lawn- grass ecosystem into a system dominated by annual weeds (and we observed several of these weed patches, mostly tucked away in spaces outside of fence lines, on our walk).
Over time (a growing season or two) these relatively simple annual weed systems would accumulate species and become an increasingly complex, perennial weed ecosystems (we did not observe perennial weed patches on our walk…societal and peer pressures probably prevent this degree of succession from being tolerated in such close living quarters!). Succession would not stop with these weeds, though. The perennial weed system would continue to grow and mature into a shrub patch full of raspberry canes, hawthorns and whole slew of exotic invaders like multiflora rose and barberry. These shrub systems are very common out away from the neighborhoods in much of the surrounding, abandoned farm yards and fields.

Photo by D. Sillman

Photo by D. Sillman

Eventually, these shrub patches would develop into forests of first fast growing, sun-loving trees (like red maple, or black cherry, or white ash, or yellow poplar (the very trees that dominate the woodlot on the edge of my mowed field)), and, over time, a more complex forest of slower growing but longer lived tree species would develop.

To the grass manager, this successional process must be directly battled in its earliest stages with the familiar tools of modern lawn care: mowers, trimmers, herbicides, irrigation, and fertilizer. The grass manager (i.e. the home owner) sets up a regime in which the grass plants are vigorously stimulated to grow (by the addition of water, fertilizer, lime etc.), and in which less desirable plants (the “weeds”) are selected against by the frequent plant tissue destruction caused by mowing (and the more you “feed” and water a lawn the more you have to mow it!), or by the very occasional direct removal of “weeds,” or by the very frequent, broad application of herbicides designed to kill non-grass plants. These steps are the only way to insure that a lawn remains a singular grass ecosystem.

The cost of this control is astounding. Here are some numbers for lawns in the United States (derived primarily from EPA, Audubon Society, and The Garden Club of America publications and web sites):
1. 54 million people mow their lawns each summer weekend, 800 million gallons of gasoline are used in gas lawn mowers each year,
2. 17 million of these gallons of gasoline are spilled during refueling mishaps,
3. mower exhaust and the volatile organic chemicals from the gas spills contribute to summer ozone production in he lower atmosphere (“smog”) and also generate about 5 % of the nation’s total air pollution,
4. 78 million pounds of herbicides/pesticides/fungicides are used on lawns each year (with almost no oversight or control),
5. 3 million tons of fertilizers are applied to lawns each year (again, with almost no oversight or control),
6. 50 to 70% of the total residential water volume is used for landscaping (mostly to water lawns),
7. a total of $30 billion is spent annually on lawns (installation, care, and maintenance).
8. lawns in the United States cover approximately 50,000 square miles. This area represents the largest single, irrigated “crop” grown in the United States.

There have been some interesting studies on the historical development of lawns and the lawn culture in the United States over the past century. One of my favorites is Virginia Jenkins’ 1994 book, “The Lawn: A History of an American Obsession.” As one reviewer of Jenkins book put it, “in the 18th-century English landscape, a folly was an extravagant building or ruin. In the 20th-century American landscape, the folly has to be the lawn.” Further, “military metaphors used by advertisers and lawn-care experts alike were part of a male viewpoint that saw nature as something to be “controlled and mastered.” It wasn’t long before that a controlled lawn, once a sign of affluence, became the strictly enforced norm of good citizenship and general moral rectitude” (Book review by “Reed Business Information, Inc.,” 1994).

Photo by L. Kalbers

Photo by L. Kalbers

The growing economic and environmental cost of maintaining lawns, especially in regions of low rainfall, have begun to raise serious questions about the future of this phenomenon. Added to these concerns are the realizations that the grass plants themselves that have assumed such a dominating presence in our urban, suburban, and rural landscapes are, in fact, non-native, and, frequently, invasive plant species. Even “Kentucky” bluegrass is a plant native to Europe, Asia, and northern Africa! Above

Photo by L. Kalbers

Photo by L. Kalbers

and to the left is a picture of my friends’, Larry and Ann, original front lawn of their home in Los Angeles. Last year in response to the ongoing drought and also to a reward program sponsored by their water authority they laboriously removed the alien, invasive sod that has grown there for many years (and which had demanded both watering and mowing) and planted in its place a dry plant community that requires neither! The second picture to the left shows their new front yard ecosystem! It is not only aesthetically beautiful, but it is also much more ecologically in tune with the climate of southern California.

I contend that lawns in any climate zone are barren ecosystems. They are empty, energy and resource hungry spaces that support and sustain very little life! To a pollinator a lawn is a desert, to a small mammal or a bird it is a flat expanse of mostly unusable space. Lawns remind me of George Monbiot’s description of stepping out of a relic forest into the moorgrass covered Cambrian Mountains in Wales: the open, tree-less spaces were green deserts created by human activities and were painfully devoid of any life at all (see Monbiot’s “Feral: Rewilding the Land, the Sea, and Human Life”). If you allow yourself to visualize what these ecosystems (either lawns here in Western Pennsylvania or all of those barren mountainsides in Wales) could (or should) be, their current ecological bankruptcy comes very clearly into focus.

(Next week: Part 2 of our walk, trees and animals!)

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Signs of Summer 8: Ticks and Tick Imposters

Photo by D. Sillman

Photo by D. Sillman

I got an email a couple of weeks ago from Karen Harlan at Penn State New Kensington asking me about a deer tick “imposter.” She had heard about a small, soft bodied (“squishable,” was the way she phrased it, stressing that she would never undertake to voluntarily squish anything!) insect that had the shape, size, and coloration of the hard bodied (“unsquishable”) tick that carries, along with some other potential pathogens, the bacterium that causes Lyme Disease. Neither Deborah nor I had heard of this tick imposter, but we did a quick check and found several newspaper articles from last year about it. Interestingly, over the next couple of days we came across several current news stories about both ticks and their squishable mimics, so this discussion feels very relevant (Thanks, Karen!).

Let’s talk about some real ticks first: Pennsylvania is experiencing a population explosion in black-legged ticks (the tick formerly called the “deer tick”). This tick (scientific name Ixodes scapularis) is a small, common tick found throughout the northeastern and north-central parts of the United States. It is the transmission vector for a number of bacterial and viral pathogens including the bacterium that causes Lyme disease, Borrelia burgdorferi. For the last several years, Pennsylvania has led the nation in the number of human cases of Lyme Disease (last year (2014) there were 7487 confirmed human Lyme Disease cases in Pennsylvania up from 5904 cases in 2013).

Photo by California department of Public Health (Flickr)

Photo by California department of Public Health (Flickr)

There are a number of features of the black-legged tick’s morphology and life cycle that make it difficult to anticipate or detect. The life cycle of this species can involve combinations of over one hundred and twenty different potential hosts (fifty-two different species of mammals, sixty species of birds, and eight species of reptiles) and can stretch out over a two or even a three year period with staggered emergences of different instar stages during different months of the year. Also, early instars of this tick are extremely small and difficult to see! Above is a photo showing all of the life stages of the black legged tick and below is an idealized version of the life cycle that I described in a blog last year:

Eggs deposited in the fall in low, grassy or scrubby vegetation hatch the next summer into the very small, six-legged larva life forms. These tiny ticks typically seek out small hosts (like a white-footed mouse or a bird) but are able opportunistically to attach to larger mammals including humans. These larva, though, are not born with any of the pathogens associated with I. scapularis and are, thus, unable to transmit any of its diseases (a small piece of good news!). If these larvae feed on a host that is carrying one of I. scapularis’ bacterial or viral pathogens, though, that tick will become infected with that disease causing agent and will carry it and be able to transmit it throughout the rest of its life cycle.

After the larva has taken its blood meal it molts into the larger, eight-legged nymph life form. This molt often is delayed until the following spring. These nymphs, then, seek a host for their blood meal. These hosts are usually mammals ranging in size from white-footed mice to dogs to cats to deer to humans. Because of the timing of this nymph emergence the spring (May and June here in Western Pennsylvania) is a time of great risk for ticks bites (and disease transmission) for humans!

Photo by D. Sillman

Photo by D. Sillman

After the nymphs have taken their blood meals they molt into adults. These adults are especially abundant in the fall. These much larger ticks (size is all relative, of course!) typically attach to large mammals (like the list above). The female adult ticks take a large blood meal from their hosts and then use the energy from this feeding to make eggs. The adult male ticks attach to the same hosts, but do not feed (and, therefore, do not transmit pathogens at this stage). They are there to find a female and to mate! The males die shortly after mating and the females die after dropping off of their hosts to lay their fertilized eggs in the grassy and scrubby vegetation. Those eggs then overwinter and hatch in the summer to start the life cycle all over again.

So why have the number of Lyme Disease cases increased in recent years? Climate change does not seem to be a causative factor (warm winters do not seem to increase black-legged tick survival rates and cold winters do not seem to decrease them!). Most researchers looking at these ticks attribute their increases to increases in the most critical host in the black-legged tick’s life cycle: the white-footed mouse. Fragmentation of forest habitats and the optimal conditions of suburban ecosystems for these mice along with significant declines in their natural predators have led to great increases in their numbers. Black legged ticks, then, in their larval life stages are increasingly likely to find a white-footed mouse on which to feed and are, therefore, increasingly likely to survive to the next instar level. White-footed mice are also significant reservoirs for the Lyme Disease bacterium, so the ticks have a higher probability of assimilating and then passing on these bacteria.

The Pennsylvania Department of Environmental Protection collected and tested black-legged ticks and determined that 34% of them carried Borrelia burgdorferi. It is not known if this is an increase from previous years or not, but these data will provide a comparison baseline for future tick assessments.

Before I move on to the tick imposters, I want to stress a few things about ticks and Lyme Disease: black-legged ticks are not able to begin blood feeding (and consequential pathogen transfers) until they have been attached to a host for at least 36 hours. Careful examination for ticks and their rapid removal is a very good way to prevent contracting the Borrelia bacterium. Preventing tick attachment is an even better strategy to avoid Lyme Disease (wear long pants and long-sleeved shirts when out in the woods or fields, use DEET-based insect repellants on socks, pant legs, etc.). A thorough “tick check” after being out in a potential tick habitat is also a very effective way to reduce the chance of infection.

Photo by J. Berger, Bugworld UGA

Photo by J. Berger, Bugworld UGA

So who (or what) are the tick imposters? The ones that have gotten quite a bit of media coverage are small weevils called “billbugs” (great name, eh?). The most common billbug in Pennsylvania is the bluegrass billbug (Sphenophorus parvulus). Larvae of bluegrass billbug feed on bluegrass stems and roots and adults emerge from their overwintering hideouts in piles of leaf litter or weeds from late April through June. They are small (although they are significantly larger than black-legged ticks!), dark and, in a snouty, weevily way (all in the eye of the beholder), handsome. These adult emergences are especially abundant in wet springs and summers, and a bluegrass billbug walking up a pant leg or clustering on a shirt front could trigger a “TICK!” response in the pant leg or shirt front owner! Billbugs are harmless (except to bluegrass lawns and meadows) and, unfortunately for them, quite squishable!

yellow poplar weevil damage (Photo by T. Tigner, Forestry Images, USDA)

yellow poplar weevil damage (Photo by T. Tigner, Forestry Images, USDA)

A recent Penn State News article also talked about another tick imposter, the yellow poplar weevil. This 3 mm long, dark weevil has large antenna which can be mistaken for a extra set of tick-like legs. They have been emerging from their overwintering sites in the leaf litter  in southwestern Pennsylvania throughout the month of June in order to mate and generate their tiny larvae which feed on the soft, inner tissues of yellow poplar leaves. Once again, their tick-like appearance is in the eye of the beholder. They can’t harm people, but they can do some considerable damage to yellow poplar trees.  And, Karen, they are, like the billbugs, quite squishable!

So be careful of ticks but don’t panic if you find one, and go easy on the little billbugs and poplar weevils!

Happy summer!

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Signs of Summer 7: Bird Sounds

Carolina wren (photo by D.Pancomo, Wikimedia Commons)

Carolina wren
(photo by D.Pancomo, Wikimedia Commons)

It is a cool, breezy day today, and I am very happy to have been able to turn the air conditioning off (with an acknowledgment that I REALLY appreciated it during all of the recent days of high humidity and ninety degree temperatures!). At last I can open up the windows and breathe fresh air and listen to all of the noises going on outside.

On top of the steady percussive sounds of rain dripping off of the tree and shrub branches, the birds are really putting on a musical show. The sparrows (white-throated, song, and chipping) and the house finches are singing and trilling the main song with punctuations of blue jay whistles and robin cackles. The Carolina wrens are rolling out their long cadences, too, along with the buzzing of the chickadees and titmice. I can even hear some starlings chipping and fluting off my neighbor’s tree. Every moment is a new combination of sounds and textures. You can almost make out the new hatchling cardinals tucked up in their nests in the arbor vitae calling to their parents for more food.

Many nature writers have talked about the purpose and the complexity of these bird sounds. Jon Young in his book “What the Robin Knows” could tell without looking when a neighbor’s cat entered his backyard by the subtle changes in tone and tempo of the surrounding bird songs. Information was being exchanged, you just had to open up your ears and mind to hear and understand it.

An article about six weeks ago in the New York Times (May 18, 2015) took the discussion of bird songs to even higher levels. Two biologists (Erick Greene at the University of Montana and Jesse Barber at Boise State) talked about their research into the functionality and importance of bird songs. Bird songs, they agreed, were important not only for a specific bird species but for many other species of birds and even mammals that share the same forest habitat. Many of these songs had local and very immediate impacts, while others exerted their influences over great distances.

Photo by A. Wolf, Wikimedia Commons

Photo by A. Wolf, Wikimedia Commons

For example, chickadees seeing a raptor will begin to sing out their “chick-a-dee-dee-dee” call. This song calls other chickadees to the area to set up a “mobbing” of the potential predator. Erick Greene found, though, that was much more information in these mobbing calls than simply “get over here!” If the raptor was especially threatening to chickadees (if it was, for example, a relatively small, agile hawk like a Cooper’s hawk), then the chickadees sent out their distress call more frequently and added more “dees” to the endings! If the raptor was less of a threat (if it was a large, but fairly clumsy Goshawk, for example that a chickadee could expect to evade fairly easily) then they slowed down their calls and abbreviated the “dee” endings! Greene also found out that red squirrels picked up and mimicked the chickadees’ distress calls and even seemed to be aware of the gradations of their relative threats (red squirrels were MUCH more cautious when the Goshawk level of a warning was given!).

Photo by D. Daniels, Wikimedia Commons

Photo by D. Daniels, Wikimedia Commons

Chipmunks, on the other hand, seemed to be more clued into warning calls from tufted titmice. Titmice were also carefully listened to by many species of small birds including red breasted nuthatches. Titmice were called the “crossing guards” of the forest by Katie Sieving of the University of Florida for their influence in keeping other bird species from going out into open areas of the forest habitat during a predator warning event.

Further, Greene’s study on lazuli buntings clearly showed that a threatening hawk cruising several miles from a bunting inhabited site was perceived by the buntings by means of a rolling chatter song that ripped across the forest ecosystem at a speed of 100 miles per hour! This song was spread at frequencies too high for the hawk to hear, so the warning was being transmitted on a “private” channel for all of the small, potential prey birds. In response to the multispecies clamor the buntings were able to dive into protective shrubs well before the approaching hawk burst into their feeding habitat.

Barber is also testing what happens when the quality of the bird song warning system is compromised. Noise pollution is becoming a very serious problem even in remote areas of the United States. It was noted that 83% of the land area of the lower forty-eight states is now within two thirds of a mile of a road. Further, expanded oil and gas exploration not only generates substantial noise from drilling machinery and activities, but also includes extensive expansion of roads and road usage.

Noise is directly stressful to birds. Their overall health, vigor, and size declines in noisy environments. Noise also blocks group generated alarm calls causing individuals to increasingly have to spend their individual time and energies watching out for predators and other dangers. This energetically expensive individual “alert” time would have been better spent feeding or resting. Barber’s “artificial road noise” experiments showed an overall 25% decline in bird abundance in noisy areas with some areas being entirely forsaken by all native bird species!

Photo by D. Sillman

Photo by D. Sillman

My yard is regularly patrolled by a pair of sharp-shinned hawks. The hawks have to come into the feeder areas via all sorts of hidden routes in order to avoid detection by the chickadees, titmice and blue jays. They need to grab their prey quickly and rapidly exit the area to avoid mobbing especially by the bold jays. The sharp-shins do get an occasional bird and, obviously, secure sufficient prey to live and reproduce on, but they have to be good at the stalking, swooping, and killing or the information system of the feeder birds will thwart them. The impact of a predator is almost always the ecological and evolutionary improvement of the prey species. Instead of bigger, faster and stronger, the feeder birds are just more verbal!

Enjoy the summer!

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Signs of Summer 5: Leaves of Three

Photo by D. Sillman

Photo by D. Sillman

I take my dog Izzy for a short walk every morning right after she has her breakfast. We try to get out before the dog across the street (who is either Izzy’s arch nemesis or her boyfriend, I am still trying to figure out which) wakes up and before the general human activity up and down the block gets in motion. Izzy and I have a quiet and almost always very fruitful short walk and she can start her day with an empty bladder and colon. Always start your day with success!

Box elder (Photo by homerwardprice, Wikimedia Commons)

Box elder (Photo by homerwardprice, Wikimedia Commons)

Anyway, the other morning I was looking at the trees growing in the woodlot that borders my street as we walked along on the narrow grass strip. The names of the trees clicked along in my still un-caffeinated brain: choke cherry, sugar maple, yellow poplar, black cherry, gray birch, red maple, box elder.

And I stopped (Izzy kept on going). Box elder? I was not aware that any box elders grew in my wood lot. Box elder(Acer negundo) was a tree of my childhood. It was the tree that lined the cool, shady street that I grew up on in northern Ohio. It was the fast growing but weak wooded tree that got collectively obliterated when a thunderstorm rolled down that same street on a July 4 evening (a couple of  years after we had moved away) and turned the street from a leafy tree tunnel to a barren strip of asphalt. It is the only maple with compound leaves! How could I not have seen it here before?

Photo by D. Sillman

Photo by D. Sillman

By now Izzy was several houses away, and I ran after her and coaxed her to start back with me toward home. I stopped again at my “box elder.” Triple leaflets branched out high over my head in a dense mass of green. It was so tall! It had to have been here for years!
Something, though, wasn’t right. I looked more closely and saw the thick, fuzzy vines wrapped around the trunk of an old maple tree: leaves of three! My “box elder” was a tree sized mass of poison ivy!

Poison ivy (Toxicodendron radicans) grows abundantly in almost any habitat affected by humans. It thrives on disturbance and favors the edges and overlaps of fragmented ecosystems. It grows abundantly not only in my yard and in the ecotones between my mowed field and the surrounding woods and the woods and street but also almost anywhere in Western Pennsylvania. Deborah and I saw so much poison ivy when we hiked the Baker Trail back in 2010 that we wanted to make Baker Trail t-shirts with a poison ivy logo on them!

As I have previously noted about poison ivy (on our “Virtual Nature Trail” and also in this blog) many animals greatly benefit from poison ivy. Songbirds eat its white berries, and deer browse on its tender leaves. If fact, there is only one animal that has a problem with this plant: humans). In a sensitized human the delayed hypersensitivity reaction following exposure to the urushiol oil of poison ivy can range from an annoying itch to a life threatening anaphylactic shock.

Photo by D. Sillman

Photo by D. Sillman

A very logical question to ask about this impact of urishiol on humans is “why?”
There are scores of websites that talk about this property of poison ivy’s urishiol and relate it to a protective function for the plant. If it is a known cause of such toxic unpleasantness, then people will leave it alone. And, if people leave the plant alone, it will grow and thrive in its ecosystems.

That is very logical, but there is no long-term, evolutionary relationship between humans and poison ivy that could have led to the selection of this “protective” feature. Further, no other animals generate the allergic reaction to urishiol that humans do. As I said, birds avidly eat its berries (all of which contain urishiol), and deer and other browsers readily consume its urishiol-rich leaves. How could urishiol be protective when it has no impact on these potential consumers?

Photo by D. Sillman

Photo by D. Sillman

An Asian relative of these species may point us toward a possible answer about the function of urishiol in poison ivy. The Oriental Lacquer tree is a Toxicodendron species that grows in China and Japan. The sap of this tree has been harvested for many centuries to make a high quality varnish for wooden furniture. The urishiol in this sap is a major constituent of the lacquer and reacts with water and air to form a hard, protective encasing material. It is hypothesized that the urishiol in all Toxicodendrons carry out this function. Toxicondendron leaves are quite delicate in structure and are, thus, easily damaged by even light physical trauma. The urishiol in the damaged leaves could react on air exposure to form a resealing lacquer that helps to reestablish the structural and protective integrity of a damaged leaf. The plant benefits ecologically and evolutionarily via this urishiol repair system because it is able to put less of its total system energy into the construction of its leaves. It is thus able to make more leaves and grow more rapidly on a specific amount of available energy.

(And, by the way, the lacquers on these pieces of Chinese and Japanese furniture are capable of generating a “poison ivy” reaction in a sensitized individual. Be careful what you sit on!)

So the urishiol might be there to help repair damaged leaves. Why does it trigger such a powerful immune reaction in humans and, apparently, no reaction at all in all other organisms that come in contact with it? I have only one answer: I don’t know!

Izzy and I went back to the house. I filled up the bird feeders with sunflower seeds and dumped a scoop or shelled corn and a handful of peanuts on the ground beneath them. The crows were hungry and were cawing and calling from spruces next to the yard. Two squirrels waiting in the arbor vitae for me to go back into the house, and a blue jay watched from the red maple. They would all dive for the peanuts as soon as I went back into the house.

Coffee was more important right now that either poison ivy or box edlers.

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Signs of Summer 4: Looking for Salamanders

Photo by D. Sillman

Photo by D. Sillman

A couple of Mondays ago Deborah and I headed out for a hike up at Harrison Hills Park in northern Allegheny County. Our plan was to do a couple of hours on the rolling terrain of the park’s trails and, during pauses while Deborah looked at wildflowers, I planned to turn over some rocks and logs to look for salamanders. There is a back story here which I will get to eventually.

Photo by B. Lucas Wikimedia Commons

Photo by B. Lucas Wikimedia Commons

It was a very good day for a salamander hunt: it was cool, almost cold, really! (I even had to go back to my house to get some long pants and a jacket for the hike!). It was also cloudy and the days before had been very rainy. The soil and litter cover would be wet and very conducive to salamander activity. Salamanders are primarily nocturnal, so we expected that they would be tucked away in their daylight hideaways. Pennsylvania has a nice array of salamander species (twenty-two species from eleven genera and five families according to the Pennsylvania Fish and Boat Commission). Deborah and I have frequently seen red spotted newts (especially their red colored, land-dwelling efts) (and newts are just salamanders, by the way) on hikes up in the Allegheny Forest. We have also seen salamanders on hikes in the Laurel Highlands and on our campus nature trail. I have even found salamanders in my driveway drain here in Kiski Township. We assumed, then, that there had to be salamanders in Harrison Hills Park.

Salamanders are, of course, amphibians. They are vertebrates capable of living on land and in aquatic habitats, too. Some species of salamanders are primarily terrestrial while others are exclusively aquatic. Almost all salamanders, though, lay their eggs in water and those eggs hatch into aquatic “tadpole-like,” larval stages. These aquatic larvae have gills and feed on algae and invertebrates in their pools and ponds. They are also eaten by larger organisms (especially fish) and as a consequence have a very low, overall rate of survival!

Photo by J. Haklm, Flickr

Photo by J. Haklm, Flickr

One “solution” to this vigorous snacking on their eggs and larvae by fish involves salamanders laying their eggs in isolated, fishless “vernal pools” rather than in larger ponds and streams. These vernal pool larvae experience a much reduced fish-predation pressure but are often under a severe time constraint to grow and develop quickly because these pools typically dry out in early weeks of summer. This reproductive strategy also requires significant spring rains to fill the temporary pools. Pictured to the left is a spotted salamander. It is the most common salamander in Pennsylvania and is one of the “mole” salamanders (so called because it makes a burrow in which it spends the daylight hours). Spotted salamanders obligatorily rely on vernal pools for their reproduction.

Aquatic salamanders keep their gills into adulthood while the terrestrial ones rely on relatively simple lungs and also their moist skin to exchange oxygen and carbon dioxide. When you pick up a salamander you are guaranteed to get your hand covered with slime, and it is important to remember that all sorts of bacteria live commensally in this mucous coating (so, always wash your hands after playing with or petting a salamander!).

Adult salamanders eat all sorts of invertebrates and are in turn eaten by many larger predators (including snakes and many types of birds). An article about Pennsylvania salamanders by Ben Moyer published about a year ago in the Pittsburgh Post-Gazette mentioned finding eleven redback salamanders in the crop of a recently shot wild turkey!

Salamanders specifically and amphibians in general are under a great deal of stress here in Pennsylvania. They have experienced significant reductions in their distributions and in their numbers. Loss of habitats (especially loss of vernal pools and other wetlands), acid rain, air pollution, and habitat fragmentation (many amphibians travel significant distances to return to their mating pools in the spring and the more roads they have to cross the greater the likelihood of fatalities) have all contributed to their declining numbers.

Globally, a chytrid fungus epidemic is causing what has been characterized in the scientific literature as an amphibian mass extinction. Many species of frogs and salamanders in Central America, South America, eastern Australia and western North America have been annihilated by this devastating and rapidly spreading disease.

But, back to Harrison Hills and our walk: we parked near the large upper playground of the park where a busload of school children and an armada of parental SUV’s had gathered for a very chilly, end-of-the-school-year picnic. We headed off on the red blazed Scout’s Trail and stopped in low spots along the way to turn a log or a rock or two, but we didn’t see any salamanders.

Photo by Mike's Birds Wikimedia Commons

Photo by Mike’s Birds Wikimedia Commons

Crossing the edge of the soccer fields we watched two male Baltimore orioles streaking around each other and singing their territories from the tops of bordering trees. We walked past the pond (the water lilies were in flower!) and turned a few more logs but still no salamanders. Last year at this time we watched dozens of American toads mating in the pond. It is quiet here today, though. We then followed the yellow blazes up and down the hilly terrain of the very reliably wet and frequently muddy Rachel Carson Trail. We turned some logs over in the wet bottom sections of the trail, but still no salamanders.

We heard pileated woodpeckers calling and pounding away, and we came across several, large, black cherry trees that they had carved up with their rectangular, chiseled holes. We heard another bird singing off in the woods, but couldn’t place its song or see it through the layers of branches and leaves. We also startled several deer from their deep, daytime hideouts.

We walked for almost two hours noting the waxing and waning flowering of many plant species and fruitlessly turning over logs. We then returned through the picnic din of the celebrating school children and climbed back into the car ready for some hot soup. We were far too damp and muddy, though, (salamander hunting is dirty work!) to go anywhere but home to get some. A nice walk: not many new flowers, only a couple of birds, and, sadly, no salamanders.

The question about salamanders was posed by Patrick Kopnicky: are there any salamanders in Harrison Hills Park? He had never seen any there, but was that because they were just uncommon or just because they were nocturnal? He speculated that the proximity of the roads and highways might make the surface water quality in the park too salty for salamanders. The lack of suitable spots for significant vernal pools in the park might also be a factor that would greatly limit the occurrence of salamanders. Also the two ponds in the park are both full of fish which we know would not be good for many salamander species. I told Patrick that I would look around. No answer yet, but I will keep looking!

Happy Summer!

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Signs of Summer 3: A Hike at The Todd Nature Reserve

Photo by D. Sillman

Photo by D. Sillman

The Todd Nature Reserve (formerly called “Todd Sanctuary”) is a rocky, stream crossed, 176 acre site owned and maintained by the Audubon Society of Western Pennsylvania. The Reserve is in Sarver in southeastern Butler County and has been, for all of the thirty-two years Deborah and I have lived in this area, one of our favorite places to hike. There are five miles of crisscrossing trails in the reserve that include a two mile “Loop Trail” that encircles the site’s perimeter and takes you from stream beds to ridge tops and back again through young to middle-aged hemlock stands and a variety of mixed hardwood forests. There are also a number of shorter trails (with wonderfully descriptive names like “Hemlock,” “Indian Pipe,” “Pond,” “Warbler,” and “Polypody”) that interconnect fern capped rock cities with densely vegetated copses and the human-constructed pond (built in 1969).

When we arrived (12:30 in the afternoon on a beautiful Saturday afternoon!) there were seven other cars in the parking area! This might be a record parking lot crowd for Todd! Many of the people apparently had decided to walk the Ravine Trail (we heard their voices disappearing down into the hollow), but even with the ones that stayed up on the forest trails, we felt like we had the reserve to ourselves. These trails never seem to be heavily used and have, in our experience, never been at all crowded.

Photo by J.McCulloch, Flickr

Photo by J.McCulloch, Flickr

At the parking area there is a tall, wooden tower with a chimney swift picture and descriptive sign on it (there is, as we will find in little while, a second, wooden, “swift tower” up by the Naturalist’s Cabin, too). Chimney swifts (Chaetura pelagica) are native birds of North America that, quite obviously, existed here prior to European colonization (and the subsequent construction of chimneys!). Chimney swifts are small, dark gray birds with long, slightly curved wings, and stubby tails. Roger Tory Peterson famously described them as “a cigar with

Photo by National Park Service

Photo by National Park Service

wings.” These birds are gregarious. They often nest in very large groups and forage on the wing for flying insects in smaller groups of 3 to 4 birds. The anatomy of their legs and feet prevents them from perching on branches or even walking on the ground. They are designed specifically to grip onto the vertical sides of their chimney habitats. Before there were chimneys in North America these swifts utilized tall, hollowed out trees and vertical crevices in cliffs for their resting and nesting habitats. It is likely that the proliferation of human-made chimneys increased their numbers significantly. Lately, though, the numbers of chimney swifts have begun to decline possibly because of a decreasing number of suitable chimneys for their roosting and nesting. In 2010 they were re-classified as “near threatened,” and the construction of artificial, vertical roosts seems a logical way to reestablish their needed habitats.

Deborah and I watch chimney swifts flying out over our field at home almost every summer morning and afternoon. It has been estimated that a mated pair of swifts with three nestlings will catch and consume up to six thousand housefly-sized insects each day, and if we converted that figure into to “mosquito-sized” insects I bet that it would sound even more impressive!

Baneberry (Photo by D. Sillman)

Baneberry (Photo by D. Sillman)

We hike down the gravel path to the bridge that crosses the ravine of the small creek that connects into Watson Run (the main stream that cuts through the reserve) and, passing the Naturalist’s Cabin cross a field that is VERY full of poison ivy! We are careful to stay in the middle of the narrow trail! On the way Deborah sees two plants (one in flower and one just past flowering) that she does not recognize! We stop while she takes pictures and closely examines the leaves and flowers. One of the plants she identifies as baneberry (Actea spp.) while the other is still under consideration.

We walk past the tangle of poison ivy and enter the cool and quiet of the shady hemlock forest that lines the banks of the creek. THIS is my kind of forest! The air is cool and wet and smells of damp hemlock needles. The sunlight is broken up into spotlight-like rays that highlight some of the forest floor plants and leave the others in deep shade. The water flow over the rocks in the creek makes a steady background noise that is loud enough to cover up the scuff and crackle of our boot steps. It is so peaceful!”

Photo by D. Sillman

Photo by D. Sillman

The Loop Trail is clearly blazed with red marks. We hike steadily up and leave most of the hemlocks behind. In the hardwood stands there is a large amount of downed wood. Branches and entire trees have fallen in parallel lines all around and all along the trail. This is a sign of a young forest shedding its early successional species and, possibly, stretching itself into a more complex structure. The downed trees are foot diameter black cherry that are well riddled with woodpecker holes and some even larger oaks that may have succumbed to the accumulated stresses of the repeated gypsy moth outbreaks of the early 1990’s. A few of the trees are broken high up on their trunks probably after some weakening events. There are also many others that have been completely wind thrown and lay across the forest floor with twelve to sixteen foot root balls that have been pulled up out of the shallow, rocky soil. In these sun gap areas black cherry and yellow birch saplings an inch in diameter and twelve feet tall grow thickly. I think that it would be possible to determine the ages of the wind throws by measuring the sizes of the fast growing trees within their sun gaps.

In the understory vegetation there are a large number of white oak seedlings and saplings! Looking back at some of my notes from 2010 I mention that there were very few oak seedlings along this trail! These oaks, then, are a recent addition to this forest! In time, with luck, a fine oak forest will come to dominate these upland sections.

Mayapple plant with flower bud circled

Photo by D. Sillman

The broad, flat, parasol-like leaves of Mayapple (Podophyllum peltatum) spread out alongside the trail. Most of the plants are setting their fruit but a few still retain their delicate, white flowers. This perennial plant grows from expanding rhizomes and often forms large, interconnected patches of dozens to hundreds of genetically identical plants. Mayapple relies on soil fungi (mycorrhizae) to assist their uptake of soil nutrients. Competition with plants that inhibit these soil fungi (like garlic mustard) can be very harmful to Mayapple. Reproduction in Mayapple is via both vegetative growth (the expanding rhizomes) and via sexual reproduction (flowers that form fruit after pollination). There is a steep physiological cost involved in making flowers and fruit, and, as I have mentioned before, and this cost can significantly drain the energy reserves from the colonial rhizome and may even cause the interconnected clonal colony to die.

There are small gnats swarming around our faces. These gnats are mentioned in almost every set of notes that I have taken on walks in Todd! They seem to fly slower than we can walk, though, so keeping moving reduces the density of their clouds. Multiflora rose is growing in scattered patches that are larger than they were five years ago. Garlic mustard is also more abundant. These two invasive species have the potential to do a great deal of harm to the native plant species in the reserve. There is still a very nice array of native plants that are still in flower: columbine, clustered snakeroot, bluets, violets, golden ragwort, wild geranium, Canadian mayflower, and sweet Cicely light up the trail with their blooms. Ferns are also abundant along the trail including Christmas fern, evergreen woodfern, New York fern, sensitive fern, interrupted fern, hayscented fern, cinnamon fern, and rattlesnake fern (one of Deborah’s favorites). There is also an abundance of raspberry and blackberry along the trail (good news for some quick snacks on our later summer hikes!).

Photo by D. Sillman

Photo by D. Sillman

As we walk up to the pond, bullfrog tadpoles as big as my thumb dart from the open water into the leaf covered bottom mud. Several adult bullfrogs float half submerged among the dense leaves of the pond lilies. In the distance green frogs make their distinctive, plunked calls. Two wood ducks swim near the far shore and hide in the shoreline vegetation upon seeing us. Deborah and I agree that we need a pond. Just being near the water is relaxing and rejuvenating!

We hike back toward the cabin crossing a stone path over the running creek. An old, shallow limestone quarry is off to the right of the trail. The rocks and the carved out depressions are completely covered with overgrowing vegetation.

We cross the cabin bridge and hike up the gravel trail toward our car. The way up seems much longer than the way down had been. There are only three cars left in the parking area, but we have only seen one other group out on the trails.

We open up the car doors to let out the accumulated heat. The air is warm and dry and a hunt of insect spray underlies the scents of the surrounding woods. It is beginning to really feel like summer!

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Signs of Summer 2: Herbs and Mushrooms, Treasure in the Woods

Photo by US FWS

Photo by US FWS

Wild ginseng (also called “American ginseng” (Panax quinquefolius)) is a slow growing, perennial, understory plant that was once found extensively throughout our Western Pennsylvania forests. Wild ginseng makes a thick root over a period of four to six years in which a chemical called “ginsenoside” becomes highly concentrated. Ginseng root is used in traditional, Oriental medicine and has a long list of potential impacts and applications. It is said to lower blood cholesterol and glucose levels, to promote relaxation and reduce stress, and to increase body strength. Scientific testings of these medical impacts by independent researchers, however, have not clearly demonstrated ginseng’s effectiveness or usefulness as a treatment for human diseases or infirmities.Belief, however, can be a very powerful force!

Photo Public Domain

Photo Public Domain

American ginseng was first discovered in 1702 in southern Canada by a French Jesuit who had read about the ginsengs of China and recognized similarities in both the morphology and also the native uses of this North American plant. Subsequently American ginseng was found growing all through the eastern forests of North America, and its harvest (often by free ranging “seng-diggers” (like Daniel Boone!)) and exportation to China quickly grew into an industry that was exceeded in terms of cash flow and profits only by trapping and the exportation of furs. By the late 1800’s the growing scarcity of wild ginseng led to the controlled cultivation of the plant, and by the 1970’s very little wild ginseng remained. Today the United States, primarily from cultivated plants grown on ginseng farms, exports over one hundred million dollars of ginseng to Asia.

It is still possible to find wild ginseng in our eastern forests, but as Hilary Appelman indicated in her February 3, 2015 Penn State News article the continuing pressures of its illegal harvesting is seriously impacting its distribution. Landowners are being encouraged to cultivate ginseng in their forested habitats in order to reestablish this once important plant back into our ecosystems.

Photo by D. Sillman

Photo by D. Sillman

Deborah and I occasionally see dwarf ginseng (Panax trifolius) plants along our hikes. These plants, though, do not produce the large, ginsenoside-rich roots that has made the closely related American ginseng so desired. If we do find any wild, American ginseng we would probably keep its locations secret in the hope that these plants could, over time, re-establish themselves in at least some small corner of our Western Pennsylvania woods.

Late Spring and early Summer is also the time of year to find a few types of edible, wild mushrooms. One type that is highly prized by mushroom collectors is the morel. We have come across morels in a variety of places but almost always they are associated with American elm trees. The impact of Dutch elm disease has reduced the abundance of the American elms, but there are still enclaves of this magnificent tree throughout our Western Pennsylvania woods.

Morels are the reproductive, spore-producing structures of a variety of species within the fungal genus Morchella. Morels are found throughout the forests of North America and in most of the temperate forests (i.e. forests that have significantly cold “winters” usually with appreciable snow) of the world. Their wide tolerance of ecological conditions, though, and their ability to handle (and even thrive upon) massive ecological fluctuations, have resulted in their frequent occurrence in many other types of ecosystems.

Photo by D. Sillman

Photo by D. Sillman

Morels are delicious, and also very distinctive mushrooms, but they should be collected and consumed with caution. Toxins that can cause digestive upsets are typically broken down in cooking, but morels can also concentrate pollutants, herbicide and pesticide residues, heavy metals, and even radioactive nucleotides from their environments. Collection of these mushrooms from disturbed or polluted areas is discouraged. Also, eating morels, even after cooking, while also consuming alcoholic beverages is discouraged because the ethanol in the drinks can intensify the toxicity of the chemicals in the morel’s tissues. You have to enjoy your morels without an accompanying glass of wine!

Morels can be found in wide range of natural and human modified habitats and in association with a wide range of tree species. Elms, in particular, as I mentioned before, are a very commonly associated tree. It used to be thought that morels were fungi that lived by decomposing the dead or dying tissues of trees and other plants. More recently, however, this “saprotrophic” ecological existence has been expanded to account for the presence of these fungal species in association with the living roots of many of their associated trees. These root-symbiotic fungi are called “mycorrhizae,” and they function to significantly assist the host tree in the absorption of soil nutrients.

The tendency of morels to form mushrooms in great numbers after fires or during and after their host tree’s death may be an example of this mycorrhizal fungus receiving a saprotrophic nutrient burst from the dying host, or it may reflect an evolutionary strategy by the morel species in which reproductive spores and formed and dispersed from a soon-to-be exhausted host system.

We have found several morel sites along our hikes over the years, but we have not collected any of the mushrooms. Most of our hikes skirt the edges of mining and chemical agricultural sites, and, so, we are quite wary of the toxin levels in the mushrooms. Also, we want the morel spores to spread along the trails and establish as many new mycorrhizal systems as possible.

So out in these Spring and Summer woods are species rich in history and chemical and nutritional potentials. Beauty and utility! Happy summer, everyone!

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Signs of Summer 1: Honey Bees, Millipedes, and Migrant Birds

Photo by I.Tsukuba, Flickr

Photo by I.Tsukuba, Flickr

Last week Deborah and I were down on Roaring Run with Rob and Michele Bridges getting ready for a late afternoon bike ride and walk when I saw a great cloud of honey bees hovering over a recently mowed area near the start of the trail. I hadn’t seen such a dense crowd of honey bees along this trail in years and so went over to watch them.

The bees were very calm but also very intent in their search patterns over the freshly cut area. They kept landing and rising and moving from spot to spot in a very random but, somehow, very orderly manner. It was like they were going from flower to flower in a field, but there were no flowers in their search area. I did see a number of cut violet leaves in the low growing plant mix of the “lawn,” and I wondered if the bees might have been foraging among the violets prior to the mowing and then have continued to receive and interpret chemical “flower” signals even after the flowers had been torn away? When I came back to the trail head after an hour and half of riding all of the bees were gone. Very curious, indeed.

Photo by AlphaWolf (Wikimedia Commons)

Photo by AlphaWolf (Wikimedia Commons)

Last week I noted a lack of forest millipedes on Roaring Run (compared to previous years), but I am very glad to report that they are back in their expected numbers! Rob and I had to keep our eyes on the trail ahead because there were dozens and dozens of them (called the “North American millipede,” Narceus americana) crossing the path in front of our bikes. These millipedes thrive in cool, moist forests that are full of leaf and woody debris. They are important components of the decomposer web by which carbon in plant materials is converted into soil organic matter and nutrients are recycled for new plant growth. They are large but quite harmless to people. They can, if they are disturbed, however, secrete a yellow liquid that can stain your fingers. These millipedes are eaten by many birds, amphibians and reptiles, and they are a particularly favorite food of shrews. I managed not to run any of them over, but there had been some millipedes beforehand that had not been so lucky.

I am still searching for several of our expected migrant bird species! Today, Deborah and Michele saw a male and female rose-breasted grosbeak flying together across the path near the start of the trail, but there are many other species that are still “missing.” I have not yet seen a scarlet tanager or an indigo bunting, although both of these birds are expected summer residents along Roaring Run. I also haven’t seen or heard any wood thrushes, another expected species along this trail. I did see a hermit thrush in Harrison Hills Park and may have even spotted its nest, but I want to hear the wild, fluting song of a wood thrush before I can really acknowledge that summer has arrived! Sometimes you just get out of phase with these birds: your time of looking just doesn’t match up with their time of activity. I need to shift my bird-biking trips to other times of day!

Photo by D. Sillman

Photo by D. Sillman

Just past the three mile marker along the bike trail we saw an early patch of fire pink growing out of the crumbling soil of an exposed slope. Its bright red petals stood out sharply against the bare, black soil of the slopes. Fire pink was the flower that Deborah and I saw every day of our Baker Trail hike five years ago. As we hiked north in the early summer, we followed its blooming phases all the way up into the Allegheny Forest.

Photo by D. Sillman

Photo by D. Sillman

Our bluebird nesting project up at Harrison Hills Park is going along very nicely! We have decided to call ourselves the “Cavity Nesting Team” because of the abundance of not only bluebirds but also tree swallows that are utilizing our nest boxes. The team has steadily dealt with repairs to the poles and boxes, wasps, house sparrows, and most recently explosively growing poison ivy and the specter of deer ticks along our access paths. The team celebrated the first hatching of “our” bluebirds with a level of joy usually reserved for new additions to one’s family! Our data so far: four boxes have confirmed bluebird nests with eggs (above is a photo of bluebird eggs in one of our boxes!), and, as of mid-May, three of these boxes have nestlings (a total of twelve to fifteen baby birds (they are very hard to count when they are all smushed together in the nest!)). Five of the nestlings fledged last week, and we will be checking the boxes to see if the others have followed suit! Five boxes have confirmed tree swallow nests, and four of these nests contain 4 to 5 eggs (no nestlings as of last week, but we’ll check again this weekend!). Two boxes had house sparrow nests, and one box has a wren nest. I will let you know how fledging goes over the next few weeks!

Summer is here! Enjoy!

Posted in Bill's Notes | 2 Comments