Signs of Summer 13: A Monarch Update and True Names

Photo by D. Sillman

Photo by D. Sillman

Monarch update! There have been several monarchs fluttering around my stand of milkweed plants. I am watching closely for caterpillars! These will be the larvae of the migrating butterflies, the ones that will fly all the way to Mexico. I am sure that one of the monarchs was a female, and I hope that she was laying eggs!

But, back to this week’s blog!

There are two kinds of names for biological organisms: common names and scientific names. Common names are familiar, usually generalized, and are easy to remember. Scientific names sound like Latin (because most of them are!), are hard to spell and pronounce, and are often very difficult to remember with any degree of precision. So why don’t we just use common names?

Let’s think of the common name “red worm.” That name fits two different species of earthworms, a roving “bristle worm” found in estuaries, a large nematode parasite found in herons and egrets (and a bunch of intermediate hosts, too), and a thin, freshwater sediment dwelling worm that is an EPA indicator species and often used as fish food. And, that’s just a partial list! So, if I wrote an essay about a “red worm” there would definitely be a high level of uncertainty about what organism I was discussing.

That’s where the Latinized, scientific names come in. While their spellings and pronunciations seem more than a bit strange, they always refer to just one type of organism! So if we say Eisenia foetidia or Lumbricus rubellus we know which type of “red worm” earthworm we are referring to. Or, if it’s Neris diversicolor, or Eustrongylides ignatus, then we know that we are talking about the errantial polychaete out in the estuary or the parasitic nematode in a blue heron. Or, if it’s Tubifex tubifex, we know that we’re talking lake or river sediment worms (or fish food).

There are lots of rules for writing scientific names. One very important one is that they are written in italics (or underlined). It’s like the title of a journal, or a book, or a web site in a bibliography, the italics sets the scientific name apart and emphasizes its singularity and importance. I’ll save the other rules for my biology students, but it is quite amazing how often they are ignored in newspapers, magazines, web sites, and sophomore biology research papers!

So, in my postings for this blog I have tried to be as precise as possible as to which species I was talking about. I try to include the scientific name in the post (and work very hard to spell it correctly!).

There are, though, two very different views of scientific names in biology, and these views seem to be based on a degree of appreciation of the importance of organisms in our view of life. It’s very interesting to realize that there are many biologists who really have had no training in or experience with actual, living organisms! These molecular biologists live in a world of proteins and nucleic acids and are exploring the depths of the reality of life well away from the requirements of looking at intact animals, plants, fungi, or even bacteria.

A great example of this new type of biologist is the person who led the team that sequenced the genome of the Neanderthals, Svante Paabo. In his book (Neanderthal Man: In Search of Lost Genomes) he refers to the instructions that he gives to his graduate students who use Latin, scientific names in their manuscripts, “I always delete the Latin and sometimes even snidely ask who they are trying to impress by saying Pan troglodytes instead of chimpanzee.” Now Paabo is a brilliant molecular biologist, and his book on the search for the Neanderthal genome is excellent, but his attitude toward zoology in general (he admits to not knowing that insects were animals) and taxonomy in particular (“a sterile, academic exercise”) needs some expansion.

Carl von Linne (Public Domain)(Wikimedia Commons)

Carl von Linne (Public Domain)(Wikimedia Commons)

In another book, The Species Seekers, by Richard Conniff the religious fervor of Carolus Linnaeus (to use the Latin version of his name!) and his students to both see and describe (and name) all of the species on Earth and to put them in a taxonomic order “for the greater glory of God” is vividly described. Many of Linnaeus’ students were so driven by this quest that they committed themselves to some of the far ranging voyages of exploration of the Eighteenth Century (and about half of them died on these expeditions!). Theirs was not a sterile exercise, but a flesh and blood drive to see and know!

Reality, as is usually the case, is somewhere in between these two extremes. We need to appreciate the detail and meaning of our scientific nomenclature without having to throw ourselves out to sea in leaky, wooden boats.


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Signs of Summer #12: Green Apples, Symbioses and the Gene Pool

Photo by D. Sillman

Photo by D. Sillman

Deborah and I were sitting out on our deck a few nights ago watching the flurry of activities that always precedes sunset. The main event of the evening involved two squirrels playing tag and chase up in one of the apple trees down in the orchard. They were bumping into each other, jumping over each other, and just having a great time. They shook the branches of the apple tree so hard with their acrobatics that a steady rain of tiny, green apples poured onto the ground. Standing under the apple tree were two fawns, and they were happily eating the sour, green apples as quickly as they fell.

Squirrels and deer interacting via the apple tree, who would have predicted that?

Ecology is the scientific study of the interactions going on in an ecosystem. These interactions can be between organisms and also between an organism and the non-living parts of its environment. A word that has grown in meaning over recent decades is “symbiosis.” At one time symbiosis meant two species that interacted and benefited each other, but now it defines all types of interactions between species. Symbiosis, then, is the essence of what is studied in ecology! Symbiosis is what was going on in and under our apple tree!

Looking out at my yard and field I can see many examples of symbioses. There are the young oak trees shading out the older spruce trees and grape vines wrapping up and over the crowns of the arbor vitae (both are examples of “perfect competition:” one species will “win” and one species will “lose”).

Photo by D. Sillman

Photo by D. Sillman

There are lichens growing on the rocks and also on a number of the tree trunks around the yard. Lichens are fungi that have algae living inside of their cells. The fungus relies on the algae to make sugars via photosynthesis, and the algae rely on the fungus to give it a place to live. Both organisms benefit from this interaction. It is a type of symbiosis called “mutualism.”

There is a cardinal’s nest up in the branches of one of the blue spruce trees. This interaction is a great benefit for the cardinal but has no real impact on the spruce. When one species is benefited in an interaction and the other is unaffected this sets up a symbiosis called “commensalism.”

On the ground beneath the spruce tree a robin pulls an earthworm out of my leaf pile. This is a symbiosis called “predation.” The robin benefits but the worm is harmed.

In any given time frame in an ecosystem a whole array of symbioses will occur. Out front in the yard a sharp-shinned hawk flies from her perch near the top of the spruce tree and dives down toward the birdfeeder. A blue jay perched in the lilac bush near the feeder sees the hawk coming and screeches an alarm. The feeder birds have an extra second or two to fly into the protection of the arbor vitae or scattered out across the street away from the hawk’s dive path. The hawk does not get a kill, and flies off chased out of the area by several blue jays including the one that raised the initial alarm.

The hawk gets negatively affected in all of these interactions (no supper and a blue jay chase squad ruining any chances for another attack!). The feeder birds are benefited in their interaction with the blue jay, but how does the hawk or the feeder birds in turn affect the blue jay? I would say that they didn’t affect him at all. Now, if there had been blue jay fledglings or some flock members at the feeder, then there would have been a self-benefit in sounding the alarm, but there weren’t. So, the interaction between the blue jay and the hawk generates harm to the hawk and no effect on the blue jay (a symbiosis called “amensalism”).

And, what about the observation that started this whole flow of ideas: the squirrels and fawns around the old apple tree? What kind of symbiosis is this? The fawns are definitely benefiting by the fresh abundance of apples, and the squirrels are neither harmed nor helped. So, it’s another example of commensalism! And what does the apple tree get out of this? Its fruit have seeds that are spread around the yard, the field, and the whole neighborhood in the feces of the deer (there is a lot of deer feces everywhere!). The apple tree, then, gets the chance to generate new apple trees far from the parental tree. The deer are benefited, the apple tree is benefited, so it’s another example of mutualism!

In an ecosystem there is a complex matrix of interactions that often influence each other in unexpected ways. The impact of predators on their prey species is a great example of this. Take our sharp-shinned hawk and the bird feeder community of small bird species. Sharp shinned hawks swooping in on a feeder are most likely to take the slowest, the least experienced, or the individuals that are physically impaired as their prey. The individuals most likely to survive the attack are the healthiest or the “most fit” individuals. The impact of a predator that is in balance with its prey populations, then, is improvement of the quality of the prey’s population! This has been observed in birds around suburban bird feeders, it has also been observed in the elk in Yellowstone after wolves were introduced, and in wildebeests in Tanzania in areas where a healthy population of lions are active!

I am glad that there are no lions lurking in my back yard, but it is good that there are small predators working the flocks and clusters of the various prey species out there. I like to think that my yard will have a very healthy, nimble, and fit chipmunk population because of the predation pressure exerted by my cat, Mazie, and that maybe my dog Izzy’s impact by chasing rabbits around the field each morning will be to make the rabbits more alert and somehow wilder. Izzy has never come close to catching any of the rabbits, of course, and probably wouldn’t know what to do with them if she ever did! But, if ever one of the rabbits was slow (or stupid) enough to be caught by a scatterbrain terrier who runs with her eyes closed, then the removal of that individual from the population would do nothing but improve the gene pool!

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Signs of Summer 11: Turkey Vultures

Photo by Dori Wikimedia Commons

Photo by Dori Wikimedia Commons

The turkey vulture (Cathartes aura) is a bird that everyone knows and almost no one loves. They are a joy to watch soaring along in their great circles across the sky, but the closer you get to them the less majestic they seem! They are large birds (they weigh up to four pounds and have wing spans up to six feet) and are the most abundant and most widely distributed avian scavenger in the New World. They are easily recognized on the ground by their featherless, red heads and in the air by their broad, “eagle-sized” wings that characteristically wobble just a bit as they soar in great circles in the updrafts.

Turkey vultures are found all across southern Canada, the continental United States, Mexico, Central America, and down South America to Tierra del Fuego. Birds in the northern regions of this broad distribution migrate to warmer habitats in the winter while birds in the warmer to milder regions of this range stay in place all year round. The vultures from the northeastern United States tend to overwinter in Florida or Texas, while birds in the northwestern United States migrate all the way down to South America possibly as far as Argentina. Migrating flocks can be extremely large (thousands of individuals!). Turkey vultures, though, cannot fly at night (they require the thermal updrafts generated by the heat of the day) and, so, each day along their migration routes they must seek out secluded roosts as evening approaches.

Photo by M. Baird Wikimedia Commons

Photo by M. Baird Wikimedia Commons

Hinckley, Ohio (a small town just south of Cleveland) celebrates the spring return of their turkey vultures with a “Return of the Buzzard” day on March 15. For the past fifty-seven years they have been greeting the returning flocks of turkey vultures as an important sign of spring. It makes more sense than Groundhog Day, that’s for sure (although it less aesthetically pleasing than House Cat Day!).

The turkey vulture is an extremely gregarious bird. They roost in large, communal groups in specific locations that may be used for many generations. During the day, smaller, foraging groups of turkey vultures may pause in the high branches of a tree or on the roof of an abandoned building forming a group called a “wake.” Actively foraging and flying turkey vultures assemble in great flocks that can rise together in circular paths in the thermals of the heated atmosphere. These swirling flocks are called “kettles” because of their resemblance to water boiling up in a heated pan.

Turkey vultures are very long-lived birds. Life spans up to 25 years have been recorded. They have few predators except for a “usual suspects” list of potential nest predators (raccoons, skunks, foxes, opossums, snakes, etc.). They are relatively timid birds who will, if challenged at a carcass by another scavenger (like an eagle or a black vulture), regurgitate their ingested materials for the challenger to consume. At a carcass, turkey vultures feed in an organized, individual manner. Turkey vultures waiting for their turn at the carcass are exhibiting a behavior called “queuing.” Turkey vultures respond to threats and danger primarily by vomiting on the source of the danger. Since their stomach contents are typically acidic slurries of dead animal flesh, this behavior is quite an effective deterrent against aggression.

The impact of DDT on egg shell stability reduced the turkey vulture population slightly, but the banning of this pesticide has led to a completely recovered and, possibly, growing worldwide population. Potential lethal impacts of lead ingestion (from bullets and pellets in hunter-killed animals), though, are possible threats to turkey vultures. Turkey vultures have also been killed by farmers and ranchers out of concern that these carrion consuming birds will spread pathogens and diseases from carcass to carcass. The great efficiency of the turkey vulture’s digestive system, though, very effectively destroys ingested pathogens (turkey vulture fecal materials are completely free of any pathogenic organisms).

Turkey vultures use their extremely well developed sense of smell to locate a carcass. This is most unusual since most avian scavengers and birds of prey utilize vision to find their food. This reliance on scent detection explains why foraging turkey vultures soar at lower altitudes than other types of vultures, and it may also explain their “wobbling” behaviors in flight (this motion may increase their ability to detect and precisely locate a scent source). Use of scent also enables turkey vultures to find buried or cached carcasses that had been hidden by some terrestrial carnivore. The greater abundance of turkey vultures in open or semi-open landscapes is also probably related to their particular method of finding food. Highways all over North and South America have become prime foraging habitats for this species.

Turkey vultures have extremely weak feet and blunt talons. Thus, they are not able to readily kill prey or rip at a carcass with anything other than their sharp, curved beak. They also show a distinct preference for relatively fresh kills and will not readily consume rotting carcasses.

Turkey vultures mate for life, but upon the death of a partner an individual may take a new mate. Courtship behaviors include a “dance” involving raised wings and feet and long, following flights led by the male. Nests are located in individually selected locations not far from the pair’s communal roost. The term “nest” might actually be a bit of an exaggeration in describing the egg site for a turkey vulture. It is typically a site located on the ground (in a cave, hollow log or tree stump, or in a dense mass of vegetation) where soil and leaf litter and pieces of rotting wood have been pushed aside to make a spot for the one to three laid eggs. In a given area there will be relatively few specific locations that will suitable for a turkey vulture to build its nest. A chosen site, though, may be used for a decade or more. Both parents incubate the eggs and also the nestlings. Both parents feed the rapidly growing young. Incubation time is between 28 and 40 days, and nestling developments times are between 60 and 84 days. So, at a maximum, a reproducing pair of turkey vultures may spend over four months in intense breeding and rearing of their young.

Turkey vultures are not beautiful to look at, they make no beautiful songs (in fact they lack the organ of song generation (the syrinx) completely!), they eat dead animals, they smell bad, and if you get too close to one it will vomit on you (did I mention that they don’t make very good pets?). They are, though, beautifully adapted to their scavenger role in our ecosystems and have many good if not noble traits. They form lasting social and mating bonds, they are very good parents, and they even have excellent “table” manners at a carcass!

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Signs of Summer 10: Campus Nature Trail, Succession, and Existence

Photo by D. Sillman

Photo by D. Sillman

The Campus Nature Trail is celebrating its 30th year of existence this coming academic year. The group of students who worked so hard in 1984 and 1985 to visualize, fund (via University grants), and then build the trail are now in their late forties and, hopefully, are getting ready to send THEIR kids to Penn State! The Alcoa Foundation has over the years twice contributed funds to help us expand and mark the trails and set up the web site that has become known as “The Virtual Nature Trail.” Alcoa’s help has been critical to the existence and quality of our trail!

I could go on about all of the students who have used the trail for credit and non-credit classes. I could talk about all of the student research projects that have been conducted there! I could talk about the Boy Scout groups who have earned their forestry and environmental science merit badges on the trail or about the two Eagle Scout projects that so greatly improved it. I could talk about the Kids in College classes, the FIRSTE Program nature walks, the Backyard Bird Counts, the Neighborhood Tree Counts, and the Penn State New Kensington Arboretum all of which were centered on the Nature Trail, but you get the idea that it has been an intensely used and very significant teaching and learning resource for many levels of the campus.

What do we see out on the trail? Our first theme (that was described in the brochure that I wrote on a Commodore 64 computer and printed out on a dot matrix printer back in 1984) was succession: the observation that ecological change is triggered by certain species modifying other species’ limiting factors. This was most apparent at the boundary lines between the European black pines that were planted at the top of the trail during the construction of the campus and the mixed hardwood forest (white ash, yellow poplar, black cherry, etc.) that was growing all along the surrounding ridge. The pine forest that was so well established in 1984 is now almost gone because of disease, stress, shading and aging of the trees. The forest floor that was absolutely clear of all undergrowth in 1984 is now a thick vegetative jungle of shrubs, vines, and hardwood seedlings and pole trees. Succession in just three decades has completely reshaped the forest!

The young forest of ash, poplar and cherry is also changing. I was out on the trail yesterday clearing the paths of this wet summer’s plant growth and noticed that oak seedlings (mostly red oaks and white oaks) are growing in great numbers under the mixed hardwoods. They will form the forest that will overtake the ash, poplar, and cherry when we celebrate the one hundredth anniversary of the trail in 2084 (September 4, 2084, at noon! Mark your appointment books!).

Photo by D. Sillman

Photo by D. Sillman

Kirk Dineley, a student from the early 1990’s who is now an Associate Professor in the Department of Pharmacology at Midwestern University in Chicago, (he’s the sixth person from the right in the back row of the clean-up crew picture) sent me a quote from “Life and Fate” by Vasily Grossman that puts forest succession into the a whole new light:

Once, when I lived in the Northern forests, I thought that good was to be found neither in man, nor in the predatory world of animals and insects, but in the silent kingdom of the trees. Far from it! I saw the forest’s slow movement, the treacherous way it battled against grass and bushes for each inch of soil . . . First, billions of seeds fly through the air and begin to sprout, destroying the grass and bushes. Then millions of victorious shoots wage war against one another. And it is only the survivors who enter into an alliance of equals to form the seamless canopy of the young deciduous forest. Beneath this canopy the spruces and beeches freeze to death in the twilight of penal servitude. In time the deciduous trees become decrepit; then the heavyweight spruces burst through to the light beneath their canopy, executing the alders and the beeches. This is the life of the forest – a constant struggle of everything against everything. Only the blind conceive of the kingdom of trees and grass as the world of good . . . Is it that life itself is evil?

As I have previously written, there is no morality in nature although we can find metaphors for the meaning of our existence in the ecosystems around us. We can see and embrace examples of all sorts of opposing observations: change vs. constancy, cooperation vs. competition, and altruism vs. selfishness. We are a part of all of these and we are, astoundingly, also set apart from them. The debate about whether we can choose our paths or whether we are like the trees in a forest and are simply pushed along in an existence determined by our environment has compelling arguments on both sides. That we can consider this at all reflects, to me, something that approaches truth.

So, Happy Birthday, Nature Trail!! The trails on the campus side of the stream are all open and passable, please go out for a walk and tell me what you see!

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Signs of Summer 9: More Snakes!

Carl Meyerhuber is a longtime friend and teaching colleague, and he is also a lifetime reptile lover. Carl told me last week that he had found an old Pennsylvania Fish and Boat Commission pamphlet that listed and described the five most common snakes of Pennsylvania (a copy of this pamphlet, by the way is available on line ( ). He asked me to name which snakes I thought would be on the list, and I only got three out of five!

Photo by Mike Pingleton (Wikimedia Commons)

Photo by Mike Pingleton (Wikimedia Commons)

The three that I knew were the black rat snake (called the “eastern rat snake” in the pamphlet), the eastern garter snake, and the northern water snake. These are three snakes that I have seen frequently and up close in a wide range of habitats throughout Western Pennsylvania. These are also snakes that I have written about in this blog and on the Virtual Nature Trail species pages. The two, “most common” snakes that I didn’t know are species that I have almost never seen in the wild: the eastern milk snake and the northern ring-necked snake.

Carl and I talked about the milk snake and were both quite surprised that it was on the “most common” list! I had only seen one milk snake here in Pennsylvania, and Carl had never seen any! “My” milk snake was disturbed out of a well mulched azalea bed right next to my house. We were pulling out some azalea bushes in order to clear the way for the construction of a wooden porch deck, and the snake, a brightly colored, red-black-yellow banded individual that was about 2 feet long, quickly moved out of its hideout in the mulch and headed down into my orchard and burrowed into a pile of leaves. I hadn’t seen that snake before that afternoon (even though it was living right next to my house!) and I haven’t seen it since! (My hope is, though, that it is living under the deck right now!).

So why hadn’t I seen that milk snake before, and, why hasn’t Carl, a great observer of snakes and turtles in his yard and along local hiking trails, ever seen one of these snakes? They are big snakes (two to five feet long!) and so brightly colored that they always stand out against grass or leaves. They live all across Southern Canada, and in all of the continental United States, Mexico, Central America, and northern South America! They are opportunistic feeders that eat everything from rodents to birds to frogs to other snakes, and they live in a wide range of habitats.

So why don’t we see these bright colored generalists everywhere? The simplest explanation is that milk snakes are nocturnal. They are active when we are, basically, not!

Now I just thought of a good question: why is a nocturnal snake so brightly colored? Those colors would be hardly observable in the dark, what evolutionary role could the milk snakes bright colors play?

My best answer is, “I don’t know.”

Maybe the colors help to camouflage it in its day-light hideouts? (unlikely). Maybe the colors startle potential predators that might come upon it during the day? (the more brightly colored snakes escape from the predators?) (possibly). There are a good number of possibilities and maybe’s here (and it’s speculation like this that makes science so much fun!!)

Photo by David Hoffman (Flickr)

Photo by David Hoffman (Flickr)

Carl and I talked for a while about milk snakes but didn’t get to the northern ring-necked snake. It turns out, though, that the ring-neck snake is also nocturnal. They are smaller than milk snakes (only ten to fifteen inches long) and dark colored (except for their eponymous yellow ring around their necks), and they live quite quietly under logs, and rocks, and dead vegetation especially in wet forest habitats (although they can live in many types of forest and field ecosystems). Estimates of the numbers of ring-necked snakes in a prime habitat range from 28 to over 700 individuals per acre! That’s a lot of snakes! In many regions of the United States they are by far and away the most abundant snake species! They are found extensively over the northeastern half of the United States and southern Canada, but are very poorly known and seldom observed even by those of us who might be out there looking! Like the milk snake, they are a companion species in our ecosystem, but they are active out of phase with us in time!

So, when we cluster around our campfires (or lit decks or porches) we should remember that just outside the edges of the comforting glow of light are any number of species that are thriving, mostly invisibly (to us). Raccoons and possums are slipping by in the shadows, coyotes, are padding past undercover, and great snakes like the milk snake and the ring-necked snake are slithering past keeping rodent populations (and maybe even each other!) under control and within stable bounds.

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Signs of Summer 8: Bald Faced Hornets!

Photo by Carney Lentz (Flickr)

Photo by Carney Lentz (Flickr)

I wanted to start this posting with a description of a nearby bald faced hornet’s nest. So, I walked around in the woodlots bordering my fields, and walked up and down the campus Nature Trail and was very surprised not to find at least one of these iconic, gray, football shaped nests. By now the nests should be nearly two feet long and a foot and a half wide and be a nexus of hornet activity. Maybe our cold winter was too much for the hibernating Queen hornets? Or, maybe the wet spring and summer were too hard on the developing nests? I really miss the hornets, though!

Many people are quite nervous around these insects (and with good reason!). Bald faced hornets can deliver repeated stings loaded with powerful toxins and tend to swarm any intruder that they perceive to be a threat to their nest and colony. But, their role in nature is not to harass or sting human beings! Let’s consider the good that these insets do in both their natural ecosystems and also in human dominated ecosystems. Having a large, robust colony of these hornets nearby (but too close!) is something all of us would benefit from.

Photo by Piccolo Namek (Wikimedia Commons)

Photo by Piccolo Namek (Wikimedia Commons)

The bald-faced hornet (Dolichovespula maculata) is a large (just under an inch long), black and white colored, social wasp that is found throughout North America. It is not a true “hornet” because that term is specifically used to describe wasp species in the genus Vespa. It is, instead, a member of the “yellowjacket” group (in spite of its very un-yellowjacket-like coloration!). The bald-faced hornet has many other common names including the “white-faced hornet,” the “white-tailed hornet,” the “bald-faced yellowjacket,” the “blackjacket,” and the “bull wasp.”

Their nest is made up of woody materials that have been chewed up by the Worker hornets and pulped into a mash with their saliva. This mash is spread out to dry in layers to form the walls of the growing globe. The nest contains multiple tiers of hexagonal combs all encased in about two inches of protective paper. There are air vents in the upper portion of the nest that allow the venting of excess heat. The nest begins as a very small structure but grows through the summer as the colony gets larger and larger. All of the Workers in the nest are the sterile, female offspring of the original Queen that started the nest in the Spring. These Workers have taken over almost all of the functions of the colony leaving the Queen with the exclusive job of laying more and more eggs. The Queen’s final task of the season will be to lay eggs for fertile females (new Queens) and fertile males who will then leave the colony, mate, and establish the overwintering, fertilized Queens for next year’s cycle.

Workers are very active outside the nest during the daylight hours of the summer. At night, they are active inside the nest caring for the larvae and pupae, and repairing and expanding the structure of the nest. During the day there is a constant flow of Workers in and out of the nest. These Workers are bringing food into the nest (flower nectar, fruit pulp, tree sap, and a great variety of insects upon which they prey. Larvae are fed a rich mash of crushed up insects gathered by and fed to them by the Workers.

In the process of seeking out flower nectar, the bald-faced hornets may be contributing to the spread of pollen from flower to flower and thus may act as an agent in the reproductive cycle of many plants. The fact, though, that these wasps have very smooth bodies (as described by the “hairless” or “bald” adjectives in a number of their common names) means that very little pollen actually sticks to them. They are thought to be a much less effective pollinator species than say the much hairy honeybee or bumblebee.

The impact of these bald-faced hornets on other insect populations, though, may have great ecological and even human significances. They prey avidly on a wide range of insects but seem to be especially fond of various species of dipterans (“flies”). Deer flies and horseflies are an optimal prey size, and I have observed swarms of bald-faced hornets taking these biting dipterans in very large numbers.

Many years ago Deborah and I had a horse named Ahab. Ahab, like most horses, was really bothered by deer and horse flies in the summer. Ahab learned, though, that he could stand, motionless with his legs spread next to a line of black walnut trees (one of which had a bald faced hornet’s nest in it), and the hornets would sweep across his legs and back grabbing up the biting flies. The hornets would then fly to the rails of nearby fence and rip the flies apart in a feeding frenzy. I even watched some of the hornets hovering behind Ahab’s legs waiting in ambush for a deer fly or horse fly to blunder by. This was like a cleaning station in a coral reef in which small fish swarm over larger fish to pull off and consume their parasites! Ahab always had a bit of nervous expression on his face, though, when he was standing at attention in the hornet swarm!

So, bald faced hornets eat deer and horse flies! NO ONE likes deer or horse flies!! The enemy of our enemy, then, is our friend! If anyone sees a bald faced hornet nest, please let me know! I hope that there are enough of them out there to keep the deer flies and horse flies in check!

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Signs of Summer 7: Earwigs!

photo by Niels Heldenreich Flcikr

photo by Niels Heldenreich Flickr

Everyone should go outside and pick up one of the potted plants on your porch or deck. It is almost certain that under some (or all) of these plant pots will be creatures that are nobody’s favorite insect: European earwigs!

The European earwig (Forficula auricularia) is a native, insect species of Europe, Northern Africa and Western Asia that has been accidentally introduced into a number of temperate and tropical countries around the world. Its first recorded appearance in the United States was in Seattle, Washington in 1907. It was likely brought to this country in a shipment of flowers, fruit, or vegetables. In the hundred years since it arrived in the United States, the European earwig has found its way to almost every region and every state in the country.

There are twenty-two species of earwigs in the United States. Twelve of these species (like the European earwig) are alien exotics, and ten are endemic (“native”). Only four of these twenty-two species, though, are classified as pest (or potential pest) species. Most of the earwig species in the United States actually are quite beneficial acting as shredders and comminuters in the soil decomposer community and as biological control agents (predators) for a variety of insect pests. The European earwig is classified as a pest species, but it is also acknowledged that it can also be an active predator of crop damaging aphids, caterpillars, beetles, and midges. Its role as a pest controlling agent is especially important in organic orchards and farms. In Pennsylvania, the European earwig is the most commonly found “pest” earwig species.

The name “earwig” has a long and extremely non-scientific history. It is derived, according to the Oxford English Dictionary (and who could argue with that?), from the Old English word “earwicga” which translates as “ear wiggler.” There is an ancient myth that these very harmless (to humans, anyway) insects have the ability to crawl up the ear canal of a human and then eat their way into that unfortunate person’s brain. None of this is true, and it is very unclear why anyone would have thought that it was or why this myth would persist over many hundreds or thousands of years! There have been, though, some interesting fictional adaptations of “earwicga” myth in literature and in science fiction television shows and movies.

The European earwig is a little over one half an inch long (females are larger than males). They have a dark, red-brown body, a reddish head, yellowish legs, two long antennae, two membranous flight wings (which it seldom uses) tucked under the hard, protective forewings, and two very distinctive cerci (“pinchers”) on the end of its abdomen. The shape of the cerci differs in males and females with females having straight cerci and males having curved cerci. These cerci are used to grab and secure prey and also, in males, as weapons in mating competitions.

European earwigs are nocturnal and spend the day in dark, moist places (like spaces under rocks, logs, surface vegetation, flower pots, leaf litter etc.). One frequently mentioned method of bio-control of earwigs is to make sure that your property is free of these potential daylight refuges. Earwigs are omnivorous and will consume plant materials (both living and dead), aphids, spiders, insects, insect eggs. They will consume garden plants and a wide variety of fruit and vegetable crops but, very interestingly, seem to do so when potential prey (like aphids) are not present in sufficient numbers. European earwigs also accumulate inside human habitations and can work their way into almost any open space or crevice. They can consume stored food products (flour, bread, cereal, crackers, etc.) and befoul clothes, books, laundry and more with their odiferous secretions.

European earwigs are solitary organisms and have no social behaviors or communication systems. Males and females meet up once a year, though, in order to mate. Males find females via pheromones that the females excrete in their feces. Males attracted to the pheromone then compete with each other for the attention of the female. It is thought that body size and especially cerci size are the critical variable in a male’s reproductive success. Mating takes place in early autumn.

Photo by Tom Oates Wikimedia Commons

Photo by Tom Oates Wikimedia Commons

The female then digs out a brood nest and lays her clutch of thirty to fifty eggs. This nest will also serve as the hibernation nest for the female and also for the male. The female will tend to the eggs stacking them up and then spreading them out making sure that fungi do not grow on them and protecting them from possible predators. The eggs will hatch in the spring and the first nymphs that emerge (the first “instar”) will remain in the nest and continue to be cared for by the female. The female guards and feeds the nymphs (via regurgitated plant materials) throughout the first instar stage (which is about the first month of life). This level of maternal involvement with offspring is very unusual in insects!
There are four nymphal stages in earwigs. In the second instar stage the female opens up the nest and the nymphs begin to go out at night to search for food. These second instars, though, tend to (or at least try to) return to the nest during the day. By the third instar stage, though, the nymphs have completely left the nest and move freely about the soil and litter habitat searching for food by night and seek out their own daylight refuges by day. These nymphs develop into adults in the late summer or early fall and then mating occurs and the cycle begins all over again.

Some female earwigs lay a second clutch of eggs after the second instar nymphs have left the nest. This second batch of eggs hatches and marches through the four nymphal stages very rapidly in the warm temperatures of summer and matures into adult earwigs at the same time as the cohort that hatched from the overwintering clutch of eggs.

Earwigs are preyed upon by many species of birds (including chickadees and nuthatches) and are also eaten by a number of amphibians (especially toads). They are also parasitized by the parasitoid fly Bigonicheta spinopennis and susceptible to numerous bacterial and fungal infections.

So, when you turn up a few earwigs in a flower pot or under a rock or log, try not to be completely grossed out! I think that I have received over the years more phone calls and emails about earwigs (“What are they?” “What do they do?” “Are they from outer space?”) than about any other insect (except maybe for brown, marmorated stink bugs). These insects may be doing a great deal of good out in their soil and litter ecosystems, and they are some of the most devoted and attentive mothers in all of Class Insecta! Let’s give them a little respect, at least.

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Signs of Summer 6: Milkweed and Monarchs

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

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

Last year I wrote about the importance of milkweed to the biology of the monarch butterfly. Various species of milkweed are the only plants on which the monarch can lay its eggs.  The chemicals 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. Human impacts on old field ecosystems where milkweeds can flourish are greatly reducing the distribution of this important plant and are at least one of the factors that are causing the observed population declines of this beautiful butterfly.

Over the past twenty-five years both out on the campus nature trail and also around my house I have tried to encourage the growth of milkweed. I have opened ripe milkweed seed pods and let the fluffy, floating seeds drop into the butterfly garden and succession plots that are located on the entrance edge of the nature trail. I have not subsequently, however, observed any thriving milkweed plants in these plots! The USDA describes milkweed propagation as an easy task. I have not experienced the ease of it!

My best ‘gardening” of milkweed has come around my house. Whenever I see a milkweed plant I let it grow. This has led to some discussion about the aesthetics of several of our flower beds, but playing the “monarch card” usually results in allowing the milkweed to remain. One incredibly persistent set of milkweed plants comes up through a crack in my driveway. They have been growing, flowering and thriving for at least fifteen years!
Just outside my back room where my writing desk is located there is a stand of nine very hearty milkweed plants. They started flowering a week and a half ago and have been absolutely covered with honey bees and bumble bees. I can hear their buzzing as I sit at my desk!

I mentioned last year that in spite of the presence of milkweed around my house, I have yet to see significant numbers of monarchs and have yet to observe any monarch caterpillars munching away on the milkweed leaves. I did see a monarch fluttering around the milkweed last week, though, and I have been watching the plants closely for any signs of eggs or caterpillars.

The life cycle of the monarch can be examined from two different perspectives: the local cycle of an individual and the year-long cycle of the migrating population. The local cycle typically takes six to eight weeks from egg to senescing adult, while the migrating cycle may extend the life span of an individual to up to nine months.

The local cycle begins with the adult butterflies emerging from their cocoons (their “chrysalises”). These adult may live for two to five weeks depending on temperature and other weather conditions and also on the availability of their food supply (flower nectar). The emerged females release pheromones which attract males. Females that have not mated release more pheromones than previously mated females and, thus, attract more males. Males fly after the females and force them to the ground to mate. Only about one third of these mating attempts, though, actually result in the transfer of the male’s packet of sperm (the “spermatophore”).

Monarch caterpillar (photo by D. Ramsey (Wikimedia Commons))

Monarch caterpillar (photo by D. Ramsey (Wikimedia Commons))

Females lay their eggs on the leaves of milkweed plants. A female can lay a total of three hundred to four hundred eggs and will spread these eggs over many milkweed plants. The eggs hatch in three to five days depending on the temperature. The emerging larvae feed first on the egg capsule and then begin to eat the milkweed leaves. They molt five times during this larval life stage and increase their body mass more than two thousand times. The eggs and the larvae (the “caterpillars”) are under intense predation pressure. More than ninety percent of the eggs and caterpillars will fail to survive. Eggs are eaten by ants, earwigs and snails, and larvae are eaten by beetles and other insects (like paper wasps) or killed by parasitoid wasps, bacteria, or fungi. Since the larvae are feeding exclusively on milkweed leaves they are accumulating the milkweed’s cardenolides (a cardiac glycoside that can cause the heart of a vertebrate to stop its contractions) in their body tissues. These cardenolides make the larvae (and, eventually, the adults, too!) poisonous to most vertebrates. Relatively few monarch caterpillars or adult butterflies, then, are consumed by vertebrate predators.

The end stage caterpillar then forms a cocoon (“chrysalis”) within which the tissues and organs of the larvae dissolve and are reformed into the structures of the butterfly. This metamorphosis takes between nine and fifteen days. The emergence of the butterfly from the chrysalis then starts the cycle all over again.

In the migrating life cycle there are great differences in life span and timing of reproduction especially in the Fall migrating forms. This migrating life form does not mate when it emerges from its chrysalis, instead it begins its long flight toward its frequently far distant over-wintering habitats. In these particular habitats (described below) the migrating life form enters a hibernating condition called “diapause” which can last many weeks or even months. Emergence from this diapause state then triggers mating and the beginning of the return migration back to the Spring and Summer ranges. These migrating monarchs may live up to nine months but spend much of this time period in its inactive, diapause state.

Monarchs overwintering in Mexico (Bfpage (En. Wikipedia))

Monarchs overwintering in Mexico (Bfpage (En. Wikipedia))

The two migrating populations of monarchs in North America are separated by the Rocky Mountains. The larger area east of the Rockies supports a much larger population of monarchs. All of these butterflies overwinter in the coniferous forests in the mountains of the Mexican states of Michoacán and Mexico. For the monarchs that reach the northeast states of the United States and the southeast provinces of Canada, this migration to and from this very specific overwintering site in Mexico covers several thousand miles. The monarchs that live in the smaller area west of the Rockies, on the other hand, overwinter in in coastal sites in Southern and Central California. Their migratory route only measures hundreds of miles at the most. In both overwintering sites, however, the numbers of monarchs covering the trees and shrubs while waiting out the winter months in their diapause states can be truly staggering!

Following the eastern population through their cycle blends together the local and the migratory aspects of the monarch’s life cycle. Between February and March the monarchs who have spent possibly four or five months in their diapause state, re-awaken, mate, and then begin their flight north. They fly as far north as Texas and Oklahoma and out across the southern states. With luck, they have timed their arrival in these areas with the emergence of the new, Spring crop of milkweed. The overwintering migrants then lay their eggs on the milkweed and die. The next generation then undergoes a local life cycle and the adult butterflies mate on emergence and then continue their fight northward in late March and early April. This cohort of adults then gets further north into the Midwest and mid-Atlantic states. This cohort again has ideally timed their northernmost arrival to the emergence of the new crop of milkweed. This first, post-migrant generation then lays their eggs on the milkweed and dies. The second post-migrant generation then undergoes a local life cycle sequence and the emerging adults in June or July head into the northern most states and southern Canada. Again, they lay their eggs near the end of their brief lives and die. The next generation (the third, post-migrant generation) can have two different types of individuals. One type continues on its collective northern flight while the other type turns to the south and gets a head start on the Fall return migration. The northward flying cohort lays its eggs on the northern edge of the milkweed plants while the southward flying cohort lays its eggs on the southern mass of milkweed. Out of these eggs are hatched the larvae that metamorphose into the adults that will be the long-lived migratory life forms that will then attempt to fly all the way back to the coniferous forests in the mountains of Mexico.

The migrating monarchs stop at nectar sites to drink and re-fuel. They follow a variety of cues to stay on their course including polarized light patterns, UV light patterns and the Earth’s geomagnetic fields. They also utilize weather fronts and prevailing winds to give them a flight boost and save a great deal of wear and tear on their delicate wings.
The monarch I saw on my milkweed was probably part of the third, post-migrant generation cohort. He (and he did look like a male) was probably looking for a female with which to mate and then would either fly off to the north or turn back to the south. His offspring will be the long distance migrators that will make the long trek back to Mexico.

We will see more monarchs over the next two months. Let’s keep planting and conserving milkweed (and as many natural nectar sources as possible!) so that they can sustain themselves on their long extended cycles!

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Signs of Summer 5: Several Snakes and a Slug

In the abundant growth of the grasses and weeds that we call our “lawns” there are all sorts of unexpected discoveries working their way through the stems and thatch. The ones without legs are particularly notable.

John Mizel Flickr

John Mizel Flickr

This summer black rat snakes have been extremely abundant. Down on the Roaring Run Trail, where I ride my bike a couple of times a week, I have had to frequently stop to let three and four foot long black rat snakes make their open slither across the trail from one mowed grass area to the next. There is no pattern as to whether the snakes are heading toward the riverside of the trail or away from it, and no particular time of day at which I see them, but I always stop if there is a snake crossing the trail so that I can direct other bikers and hikers away from it for fear they might accidentally run over or step on the snake. About a month ago, I came upon a group of five walkers clustered together on the trail, talking nervously. There was a black snake in their path and they were afraid to get close to it. I prodded the snake to hurry it along on its way across the trail, and they thanked me for helping them out (and, I am sure, for not making fun of them!). About a half an hour later on my return ride back to the parking lot, the same five walkers were once again stopped in their tracks by a different black snake. The snake seemed to enjoy being the object of the rapt attention of all of those people and did not seem to be in any hurry to get off the trail!

The black rat snake is one the more impressive animals found in the biotic community of Western Pennsylvania. Individuals of this species may reach lengths of 7 to 8 feet and is, thus, the longest snake naturally occurring over its broad, geographic range of the eastern United States (west to Wisconsin and parts of Texas) and southern Ontario. Most typically the dorsum (back) of this species is solid black and the venter (belly) is gray along most of its body length. The gray belly coloration changes into a solid white at the throat. There may also be a series of white spots and speckles running along its sides. There are, however, numerous color variants of this species, and individuals who are gray and even yellow are frequently found. These snakes are very important rodent predators and help to keep our natural ecosystems (and our barns and garages and yards) if not rodent free, then in a rodent balanced state.

A black rat snakeA black rat snake with whom I had a long and close relationship was “Strobe” a yellow/brown color variant black rat snake (image, left, D. Sillman). I found Strobe as a tiny, newly hatched snake slithering his way down the lower hallway of the Science Building at Penn State New Kensington. My son, Joe, had expressed interest in have a snake for a pet, so this seemed an excellent opportunity to fill that pet niche for our family. I collected Strobe in a large, Erlenmeyer flask and after a visit to a local pet store, took the “free” snake home with about a hundred dollars of pet snake equipment (habitat, heater, etc.). Joe took excellent care of Strobe for the next six years, and Strobe grew into a very impressive, three foot long, gold-colored, black rat snake. We did learn something very important as we raised Strobe, though: black rat snakes do not make good pets. He never became anywhere close to being tame and would, if an opportunity arose, escape from his expensive habitat box (and hide in the most obscure places of the house (Deborah REALLY loved that!)). He would also grab onto and constrict down on any hands and arms trying to move or feed him and bite those said hands and arms with all of the force he could muster. Now black rat snakes are not poisonous, but they produce an anticoagulant in their saliva that can allow the tiny puncture holes made by their teeth to bleed volumes way out of proportion to the size or depth of the wound!

A biology colleague over in Eastern Pennsylvania heard about Strobe and, since he was interested in the genetics of this non-black coloration of a black rat snake, offered to trade Joe a ball python named “Julius” (which was short for “Julius Squeezer”) for Strobe. Joe accepted and we then had several more, great snake years with the gentle, sweet, very appropriate pet snake, Julius.

Several years ago Jason Bush (our campus’ Director of Business and Finance) and I were out on the Campus Nature Trail looking for two metal surveying plates that marked the boundaries of the campus. I was off the trail on my hands and knees shifting through leaf litter looking for one of the plates when I saw a large diameter black rat snake gliding by. I could only see part of the snake (the rest was hidden in the leaves and ground vegetation), but as I watched the head and the first part of the body slide past I shouted to Jason “I got a three foot black snake down here …. no, it’s more like four feet … no, five … no, more like six!” It was a six and half foot black rat snake with several large bulges in its body which, I am sure, represented recently ingested rodents.

We never did find that plate, by the way!

D. DeStefano

D. DeStefano

About a month ago I got an email from Danielle DeStefano, whom most of you know as our campus’ Assistant Director of Admissions, but to me she will always be a biology student who has temporally strayed off the path of Truth! Anyway, Danielle sent me an email with an attached photograph of something she saw coming through the grass and across the sidewalk on her way into her office. The photograph is reproduced to the left.
This beauty is a leopard slug (Limax maximus) who was on his way from his nighttime prowling around looking for food to his daylight, sleeping hideout. Leopard slugs are big! They can be four to eight inches long and have gray to brownish-yellow bodies with “leopard-like” streaks of black. They are natives of Europe and have been accidentally transported to places colonized by Europeans (including North and South America, South Africa, Australia, and New Zealand). They are also almost always found near people and their habitations! They mostly eat dead plant materials but can also dine on carrion, fungi, and other slugs. They can also consume young, just sprouting crop plants almost as fast as they can grow! For this reason they are often classified as an agricultural pest.

Leopard slugs can live two and half to three years, and they tend to live alone rather in groups (or in whatever we might call a herd of slugs!). They are hermaphroditic (i.e. have both male and female reproductive organs) but reproduce sexually via some very interesting mating behaviors. A fertilized leopard slug can lay hundreds of eggs (so their population is capable of very rapid growth!).

Great find, Danielle! Keep your eyes on the ground!

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Signs of Summer 4: Two Birds

Pierre Selim Wikimedia Commons

Pierre Selim Wikimedia Commons

I have spent most of today looking out my back window and watching all sorts of bird behaviors. The chickadees have been hunting and gleaning up and down the spruce branches, the male mourning doves have been following the females on their head-jerking walks around the yard obviously ready to start the second clutch of the season, and the blue jays have been laying themselves flat on the hot concrete of the basketball court, spreading out their wing and tail feathers to cook out some of their lice and mites. The robins have been hunting for worms over on the shady lawn, and the chipping sparrows are pecking at (to me) invisible tidbits on both the grass and the sidewalk. The activity of all of these different species seems almost orchestrated. Each bird moves through its section of the habitat looking for its type of food and none of them seem to interfere with the others.

Joe Ravi Wikimedia Commons

Joe Ravi Wikimedia Commons

But then two birds arrive that disrupt the harmony of this ecological dance: European starlings (pictured above) and English sparrows (pictured to the left).

Both of these species were brought to North America back in the Nineteenth Century. The starlings have a very definite place and time of introduction: Central Park in New York City in 1890. The person who released these sixty (or sometimes reported to have been one hundred) starlings was Eugene Schieffelin, and his intention, as president of the “American Acclimatization Society,” was to introduce into North America all of the bird species mentioned in the works of William Shakespeare. So, because in “Henry IV, Part 1” Hotspur plots to have a trained starling saying the name “Mortimer” over and over to Henry with the intent of driving him mad, we got these sixty (or one hundred) starlings that then spread all across the continent and now number between two hundred million to seven hundred and fifty million individuals! They also cause eight hundred million dollars in agricultural crop damage each year and via spreading disease among cattle and pigs in feed lots probably that much again in damage to meat production. Almost two million starlings are killed each year via various pest control procedures, but as one control agent put it, the effectiveness of these control measures are “like trying to bail the ocean with a thimble.”

Thanks, Eugene.

There is a flock of fifty to one hundred starlings that roosts down the street. They cover the lawns and fields between their roost and my house, and they fill up the branches of my neighbor’s locust trees, but they seldom come into my yard. When they do swoop in the other bird species scatter and the ecological dance collapses.

Starlings are very aggressive “secondary cavity” nesters. They seek out sheltered nesting sites and evict any bird that might have been in possession of the site. This disruption of the nesting behaviors of other bird species (and the starling’s predilection to eat both eggs and nestlings of those other bird species) along with the starling’s dominant behaviors in their feeding habitats (they are quite omnivorous and will eat invertebrates, small vertebrates, seeds, and fruits … anything that is available!) have been a significant factor in the overall decline of song bird populations in North America.

There is a group that denies any of this is going on. These starling-apologists feel that it is a media-led witch hunt that has led to the bad image of this species. Even a casual reading of “Starling Central’s” web site, though, makes it very clear that their assertions are based on carefully assembled and edited facts.

I want to say some nice things about starlings, though. They sing beautifully and with a wide range of original and imitated songs. They can even be taught to speak (you could teach one to say “Mortimer” over and over!). They have beautiful, iridescent, black feathers that initially form with white tips (making the bird look spotted right after its molt), but the tips wear down and leave the shiny black plumage in its place. The very name “starling” refers to their star-like appearance in flight: a sharp pointed beak, two pointed wings, and a short, pointed tail.

Now many people really do hate starlings, but the level of antipathy to them is nothing compared to the rage of true lovers of nature that is directed at English sparrows. There was an article in the New York Times this spring in which the writer described the behavior of her mother, a kind and gentle woman who loved birds dearly, and her on-going vendetta against English sparrows (there was a scene at a birthday party in which a sack of caught sparrows were gassed in auto exhaust that was particularly ghastly).

English sparrows (also called “house sparrows”) have a murkier North American origin than starlings. Again in the late Nineteenth Century there was an active program in many cities across the country to import and establish this species. Various reasons are given for this: it was thought that the sparrows would eat insect pests. It was thought that they would peck grains out of horse manure (a big pollution problem on city streets!) and accelerate its decomposition. There is also some reference to people simply liking sparrows and wanting them around them! And, our old friends of the American Acclimatization Society also cited “Hamlet” Act 5, Scene 2 with Hamlet saying “There is special providence in the fall of a sparrow,” and used it to justify bringing hundreds of birds over to the States. So from its multiple points of introduction, the English sparrow now numbers a hundred to a hundred and fifty million individuals in North America (There are five hundred and forty million individuals world-wide, and they are found on every continent except Antarctica!).

Why are English sparrows so hated? They are very aggressive toward other bird species (a list of seventy different types of birds that are attacked by English sparrows was posted on one web site), they evict other birds from their nests and destroy their eggs or kill their nestlings, and they very aggressively compete for food at a wide range of potential feeding sites and habitats. They also form large colonies in close association with people and even frequently flock with starlings! Their interactions with eastern bluebirds (which include forcing the bluebirds out of their tree hole nesting sites and human-made nesting boxes and the killing of bluebird nestlings) have in particular energized many in the birding community to wage all-out war on these sparrows.

But, English sparrows are not evil. They do suffer from being way too successful in their introduced ranges, and they have a great ability to thrive on the wastes of human society (they are the “French fry” bird around every fast food restaurant in the United States!), but they still have many characteristics that are admirable and worthy of note. The Humane Society of the United States has a long web page dedicated to consideration of the English sparrow as a very misunderstood and misrepresented species. Like the starling-apologist group, though, the Humane Society is a bit selective in their facts and seems to intentionally ignore less seemly features of this bird.

We have to remember that there is no good or evil in nature. Survival for any species in any environment can require some ugly behaviors and some seemingly cruel strategies. A moral system and society based on Nature would be a very unpleasant place to live! European starlings and English sparrows are here to stay. I guess that we have to just get used to them!

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