Diptera and Odonata and Ephemeroptera, oh my!

Students of Water Ecology at the New Jersey School of Conservation spend their class wading in the tributaries of the Big Flatbrook, outfitted in rubber boots, turning over river-worn rocks to look for the benthic macroinvertebrates that cling to the bottom of these stones.  A benthic macroinvertebrate is an organism that has no backbone, is visible to the naked eye, and lives on the bottom layer of a body of water, often in the sediment.  Most of the benthic macroinvertebrates that students find are actually the larvae of aquatic insects, those insects that live a portion of their life cycle in the water.  In order to become an adult, these aquatic insects undergo a metamorphosis and leave the water once their wings have dried.

Perhaps our least favorite aquatic insect is the mosquito, of which there are 2,500 different species worldwide and 150 species in the United States!  The mosquito, of the order Diptera, goes through four distinct life stages, three of which are spent in the water.  Adult mosquitoes lay eggs one at a time on the surface of the water or on damp soil that will become flooded by water.  Some species make egg rafts, where the eggs stick together and float on the water.  Within about 48 hours, these eggs will hatch into larvae.  The larvae, also known as “wigglers” or “wrigglers,” live in the water for one to two weeks.  They use a tube called a siphon to breathe oxygen at the surface of the water.  Eating micro-organisms and organic matter such as algae, the larvae go through four molts, during which they shed their skin and grow larger.  After the fourth molt, they become pupae and begin the final metamorphosis to adult mosquitoes.  The pupae, who do not feed, remain in the water for one to four more days, depending on the species of mosquito and the temperature of the water.  Lighter than water, the pupa floats at the surface and uses two breathing tubes called trumpets to receive oxygen.  Pupae are known as “tumblers” because when disturbed, they dive in a jerking, tumbling motion before floating back to the surface.  Within a pupal shell, the adult mosquito develops over a period of about two days.  Finally, the pupal skin will split and the adult mosquito emerges from the skin.  At this point, the adult will rest on the surface of the water, allowing its new body to dry and harden and its wings to spread.

Mosquito Larva

The adult male mosquito only lives for about a week, while the adult female mosquito lives for about a month.  However, temperature, humidity, and time of year also affect the lifespan of this insect pest.  If you find yourself sitting outside on a summer evening, slapping away at the mosquitoes biting your ankles, you are actually targeting only the females of the species!  Female mosquitoes depend on the protein in blood to produce their eggs.  The males, in contrast, only feed on flower nectar and other plant juices.  Humans aren’t the only ones that these ladies bite, however; cows, chickens, deer, rabbits, snakes, frogs, and many other types of animals also make up a tasty dinner menu.  If you’re worried about the mosquitoes being a problem in your yard this summer, make sure you eliminate any standing water; mosquitoes aren’t picky, so they will lay their eggs in any kind of water!  Keep in mind that mosquitoes make up an important part of the food chain, providing sustenance for many creatures, including bats, frogs, and fish.

Preferring cleaner water than the mosquito to lay their eggs, dragonflies and damselflies are aquatic insects that belong to the order Odonata, which means “toothed ones.”  They are called this because each dragonfly and damselfly has a prehensile labium, or extendable jaw, beneath the head; this jaw can extend faster than most prey can react.  This adaptation makes the bite of the Odonata fatal to its prey, which includes mayflies, caddisflies, gnats, ants, termites, and other small insects.  All six legs of the Odonata are located close to the head; rather than using their legs for walking, the legs are most often used to catch prey or to perch.

Dragonfly Larva

It is easy to tell the difference between dragonflies and damselflies.  Dragonflies have stout bodies and when resting, they extend their wings to each side.  The damselfly, in contrast, has a very slender body, and when resting, holds its wings together above the body.  Dragonflies and damselflies are additionally characterized by their eyes, which are very large in proportion to their heads.  Their eyes are so large that over 80% of brain power is devoted exclusively to analyzing visual information!  Odonata species have two pairs of long wings that are made strong and flexible by a strong crossvein and many small criss-crossing veins.  With these wings, dragonflies, who can fly faster than damselflies, ambulate forward at about 100 body-lengths per second, backward at about 3 body-lengths per second, or hover in the air for about a minute.  While most species have wingspans that are about 5 to 8 centimeters wide, 325 million-year-old fossils show that ancestors of dragonflies had wingspans up to 30 inches wide!  With exceptional sight and agile flight, dragonflies and damselflies may escape from their predators, which include birds, lizards, frogs, spiders, fish, water bugs, and even larger dragonflies.

 
Damselfly Larva

Like mosquitoes, dragonflies and damselflies spend a part of their lives in the water.  However, they only go through three distinct life stages.  Dragonflies lay round eggs in the water, while damselflies lay cylindrical, long eggs.  The larvae of the Odonata are known as “nymphs,” and most of the insects’ lives are spent in this stage.  While a mosquito molts only four times, the Odonata may molt six to fifteen times!  In order to breathe in the larval stage, nymphs expand and contract their abdomens to move water over their gills.  Depending on many factors, they may remain in the larval stage for up to six years.  While the mosquito enters into a pupal stage, dragonflies and damselflies will simply crawl out of the water, molt one final time, and emerge from their old skin as winged adults.  Because they skip the pupal stage, Odonata are known as “hemimetabolous,” or those who undergo an incomplete metamorphosis.  With a longer lifespan than mosquitoes, adult Odanata can live for up to six months under favorable conditions.

While dragonflies are more sensitive to pollution than damselflies, both are indicators of healthy ecosystems.  Many factors affect the distribution of nymphs, including acidity of water, the amount and type of aquatic vegetation, temperature, and the type of environment.  Cool streams, rivers, ponds, marshy areas, and still clear water are favorites of various species.  Did you know that the New Jersey School of Conservation is located in the Odonata capital of the country?  Sussex County has more species of Odonata than any other county in the country, tallying in at 145 species!  Due to its varied topography and geology, poorly drained swamps and marshes, and rich boreal habitat with plenty of clean rivers, lakes, and streams, dragonflies and damselflies love to call Sussex County home.

Even more sensitive to the environment than the Odonata are mayflies, members of the order Ephemeroptera.  Mayflies, of which there are 2,000 species, are the only insects to go through two flying stages in their metamorphosis.  Mayflies mate in swarms during calm weather before depositing their eggs, flying low over the water or dipping their abdomens on the surface.  Some adults even submerge themselves and lay their eggs underwater.  Many adult females die on the surface of the water after laying their eggs.  Like mosquitoes, dragonflies, and damselflies, mayflies molt several times when in their larval stage, during which they are also known as “nymphs.”  Nymphs graze on bacteria on the river floor.  As they grow older, they form oval-shaped gills which beat in order to regulate the flow of water and oxygen through the body.  

Mayfly Larva

During the final molt as a nymph, the mayfly floats to the surface of the water and opens its wings to enter the first flying stage, where it is known as a subimago.  Floating on the surface of the water, waiting for the strength to fly, this is the most vulnerable stage of the mayfly’s life.  Once it has the strength to fly, the mayfly will find protection under a tree or in long grasses, where it will again molt within 24 to 48 hours, entering the second flying stage as an imago.  During this final molt, the mayfly’s tails and legs grow larger, giving them more stability in flight and greater reproductive success, respectively.  Mayflies, in both the nymph and adult stages, can be recognized by their three caudal filaments, or tails, at the tip of the abdomen.  As adults, their large forewings are usually kept upright, while their hind wings are reduced or nonexistent.  Once it becomes an adult, the imago will mate and then live for only hours to a day.  This is the reason that the order Ephemeroptera was given its name: ephemeros is Greek for “lasting but a day.”

The adult mayflies may only last for a day, but they let us know that the ecosystem is strong and healthy.  In their various life stages, mayflies provide food for animals as varied as snails, fish, frogs, birds, beetles, and flies.  Mayfly nymphs are extremely sensitive to pollution and poor water quality, so their presence indicates a very healthy stream.  Students in Water Ecology, collecting the macroinvertebrates they find on the stream bottom, always come up with mayfly larva, those organisms that tell us just how clean the Big Flatbrook is.  As an indicator species, this aquatic insect is very instructive of the healthy aquatic environment that students wade through on sunny afternoons.  Whether they find “wigglers,” “tumblers,” “toothed ones,” or those who “last but a day,” students curious enough to get their feet wet and flip over a few slippery river stones have a great deal to learn from the aquatic insects found in the Big Flatbrook.

References:

Introduction to the Odonata. (n.d.). Odonata: Dragonflies and Damselflies. Retrieved May 23, 2012, from http://www.ucmp.berkeley.edu/arthropoda/uniramia/odonatoida.html

Mayflies. (n.d.). Ephemeroptera. Retrieved May 23, 2012, from http://www.ucmp.berkeley.edu/arthropoda/uniramia/ephemeroptera.html

The dragonflies and damselflies of New Jersey. (n.d.). New Jersey Odonata. Retrieved May 23, 2012, from http://www.njodes.com/

The Life Cycle of the Mosquito. (n.d.). Mosquitoes. Retrieved May 22, 2012, from http://www.mosquitoes.org/LifeCycle.html

Wild Geese

And in this annual barter of food for light, and winter warmth for summer solitude, the whole continent receives as net profit a wild poem dropped from the murky skies upon the muds of March.  
 –Aldo Leopold, A Sand County Almanac

Though the winter has been mild, Lake Wapalanne has been at least partly frozen for most of the winter.  The thawing of the ice on the lake has been met with annual visitors in search of open water: Canada Geese.  Several pairs of the well-known birds have been seen around the lake, honking defensively at passersby as they stake out their nesting sites.

Canada Geese (Branta canadensis) are the most widespread goose in North America.  Everyone recognizes these long-necked, black-headed birds as they graze on lawns, pick through the stubble in last summer’s cornfields, or fly in their characteristic V formations across the gray sky.  Their deep, musical honking is a classic sound heard in the autumn as winter approaches and again when spring arrives.

The Canada Goose has a brown body and wings, black tail, tan or cream-colored breast, black head and neck, and white chinstrap.  This large waterfowl has large, webbed feet and a wide, flat, black bill.  Canada Geese live near water, grassy areas, and grain fields.  They are often found in parks, golf courses, suburban areas, and other places with large lawns both because they feed on grass and because the open space allows them an unobstructed view of potential predators.  In addition to grasses, the geese also eat sedges, skunk cabbage leaves, and eelgrass.  During the fall and winter, they will commonly eat berries, seeds, and grain and corn kernels from agricultural fields.

Canada Geese mate for life.  Pairs remain together throughout the year, and the birds are often found in large flocks.  Mates will choose each other based on size: larger males will mate with larger females and smaller males will mate with smaller females.  This practice is known as “assortative mating.”  Size may also indicate subspecies of geese; the birds generally get smaller as one moves northward.  There are at least eleven recognized subspecies, and the four smallest forms are considered a different species: the Cackling Goose.  Subspecies are also recognized by color; the geese tend to be darker as one moves westward.

In early spring, the pairs of geese break away from their flocks and begin to defend their territory, as the couples are currently doing at Lake Wapalanne.  As long as population density permits it, geese will not nest within sight of each other.  The birds are very defensive of their nesting sites, using a variety of threat displays to keep other geese away.  They will pump their heads, open their bills with their tongue raised, and hiss and honk until the intruding goose retreats.  The birds are so aggressive that they will even grab each other by the breast or throat and use their wings to hit each other.

Once territory has been staked out, the female will select the nest site and build her nest.  The nest is a large, open cup made of dry grasses, lichens, mosses, and other plant material.  It is built on the ground, often on a slightly elevated site, and lined with down and body feathers.  The female will incubate two to eight eggs alone while the male guards the nest site.  In order to properly guard the nest, the geese prefer a site with an unobstructed view.

The female will incubate her creamy white eggs for just under a month.  When they hatch, the goslings are covered with soft, yellowish down.  After only one or two days, the baby birds can leave the nest to walk, swim, and feed.  Even though they are independent enough to leave the nest so early, they stay with their parents constantly.  The young birds will remain with their parents for their entire first year, though as they grow, they become more social and congregate with other families at good food sources.

Come winter, Canada Geese may migrate long distances to spend the winter in the southernmost parts of their range.  Some geese, however, may migrate short distances or not at all.  Recently, researchers have found that the geese are not flying quite as far south as they used to.  One reason for this change in migration patterns could be that waste grain from agricultural fields has become more available as a food source during winter months.  As long as the geese find open water and food resources, they can survive icy winter temperatures.

Even though some Canada Geese are resident to an area, the species itself has come to represent migration.  Flying both night and day, the flocks of family groups and individuals are witnessed by many as they move freely between Canada and Mexico.  These migrations symbolize both change, on a yearly scale, and repetition of nature’s cycles on a longer time scale.

Quite simply, the arrival of Canada Geese at the tail-end of winter is a sure symbol of the approaching spring.  In his chapter “March: The Geese Return” of A Sand County Almanac, Aldo Leopold writes with excitement and joy about the arrival of geese on his farm: “Once touching water, our newly arrived guests set up a honking and splashing that shakes the last thought of winter out of the brittle cattails.  Our geese are home again!” (19).  Leopold’s exclamation that the geese are “home again” shows his enthusiasm for their arrival.  Not only have the birds brought spring with them, they also appear on Leopold’s farm like old friends who have returned for a visit.  The rambunctious honking of the geese, as well as the summer-like sound of their splashing on the water, chases the chill of winter out of the air.

References:

All About Birds. The Cornell Lab of Ornithology. 5 Mar. 2012. .

Leopold, Aldo. A Sand County Almanac and Sketches Here and There. New York: Oxford University Press, 1949.

Peterson, Roger Tory. Peterson Field Guide to Birds of North America. New York: Houghton Mifflin Company, 2008.

Who Cooks for You?

In September, last year’s AmeriCorps members gave Ashley, Danielle, Sam, and me a tour of the School of Conservation Campus.  It was one of the few warm days that remained, and we took our time near the canoes and rowboats near the docks on the Sequoya side of campus.  We sat on red benches in the Pavilion, a small building with removable walls, open to the late summer sunshine.  Looking up at the roof of the Pavilion, we could see the remains of nests made in spring by Phoebes and Barn Swallows.  In one corner of the Pavilion, an Eastern Screech Owl perched atop a song bird’s nest.  It was so motionless in sleep that at first, I believed that the owl was a taxidermied specimen, put there on display.  In fact, it was a living owl, but it wasn’t until the bird squinted its eyes open and peeked at me that I was convinced.

The Eastern Screech Owl (Otus asio) is one of seven owls found in New Jersey.  The most common species found in the state are the Eastern Screech Owl, Great Horned Owl (Bubo virginianus), and Barred Owl (Strix varia).  Barn Owls (Tyto alba) and Northern Saw-whet Owls (Aegolius acadicus) are also found in New Jersey, and the Long-Eared Owl (Asio otus) and Short-Eared Owl (Asio flammeus) can be found overwintering here.  

Primarily nocturnal birds with excellent camouflage, owls are often better known by sound than by sight.  In Walden; or, Life in the Woods, Henry David Thoreau writes extensively about the owls that he hears nightly at Walden Pond.  Thoreau describes the Eastern Screech Owls as “Wise midnight hags!” whose “wailing” and “doleful responses” he loves to hear.  In fact, Thoreau states, “I rejoice that there are owls…It is a sound admirably suited to swamps and twilight woods which no day illustrates, suggesting a vast and undeveloped nature which men have not recognized” (82).  Known only for the sounds they make at night, owls come to represent mystery and darkness, obscurity and ghostly twilight.  From the Eastern Screech Owl’s whistled trill and the Great Horned Owl’s deep hooting to the Barred Owl’s cackling and cawing and the Barn Owl’s hissing scream, owls are recognized by their haunting calls.

Contrary to popular belief, owls cannot turn their heads all the way around.  Owls turn their heads three quarters of the way around in order to change their field of vision.  An owl doesn’t have enough room in its head for eye muscles; therefore, the owl relies on turning its head to see from different angles.  Owls also have 14 vertebrae in their necks—twice as many as in mammals—that allow them to turn their heads.  Because owls can move their heads so far and so rapidly, it often appears that they can turn their heads around completely.  This ability to have eyes in the back of their heads helps make these birds excellent hunters, able to look in almost any direction to see the animals they hunt.

These nighttime birds of prey mainly hunt rodents such as mice.  The Eastern Screech Owl will also eat insects, songbirds, and earthworms; they will even dive for fish or crayfish.  The Barred Owl also eats crayfish; it is believed that this causes the belly feathers of some Barred Owls to turn pink!  The more vicious Great Horned Owl will eat larger animals, like rabbits, squirrels, geese, and snakes.  This owl will also prey on crows, and because of this, crows regularly mob and harass owls.  The Great Horned Owl will even eat skunks!  Most owls eat a variety of small mammals, songbirds, and large insects.  The Barn Owl and Long-Eared Owl have particularly good hearing and are able to catch prey in complete darkness.  The prey of owls can be discovered by studying owl pellets, or small masses of undigested parts from the owl’s food.  Inside an owl pellet, one can find many indigestible materials, from the bones of rodents to the exoskeletons of insects to fur or feathers.  These indigestible materials collect in the owl’s stomach, and a pellet is formed.  The pellets are expelled before the night’s hunting by regurgitation; owl pellets can often be found beneath the bird’s nest or a regular roost within the owl’s hunting grounds.

Unlike most birds, owls do not build their own nests.  Some owls, like the Great Horned Owl, Long-Eared Owl, and Barred Owl will lay their eggs in the existing nest of a hawk, heron, crow, magpie, or squirrel.  The Barred Owl may also lay her eggs in a tree cavity or an old woodpecker hole, as will the Eastern Screech Owl and the Northern Saw-whet Owl.  The Short-Eared Owl will lay her eggs in a shallow, grass-lined depression, well-hidden by vegetation, and the Barn Owl will simply lay her eggs on a bare surface, such as in the corner of a barn or attic.  Depending on the species, owls will lay between two and eleven eggs; females will incubate the eggs themselves.  In some species, the males will hunt for food and protect the nests.  Most owl chicks will be ready to leave the nest after four to ten weeks, depending on the species.

This winter, New Jersey has had an unexpected visitor.  On November 8, 2011, a juvenile female Snowy Owl (Nyctea scandiaca) was spotted at Merrill Creek Reservoir in Warren County.  At the time of this writing, the owl could still be found there.  This Snowy Owl has likely taken up residency here in New Jersey, far south of its normal range, due to a strong breeding season in the northern tundra of Canada and Alaska this past summer.  Such a rise in population has sent younger birds further south to look for food this winter.  The arrival of the Snowy Owl in New Jersey has been an exciting opportunity for birdwatchers, who have flocked to Merrill Creek to view and photograph the bright white bird.  Almost as unusual as seeing the Snowy Owl in New Jersey is getting the chance to view any of the state’s seven owl species.  The lucky birdwatcher gets the chance to view these elusive, nocturnal, mysterious birds.  Their hooting, cackling, and hissing at night are indicators of their presence, even if we don’t get the chance to see these big-eyed nighttime birds.
 

References:

All About Birds. The Cornell Lab of Ornithology. 25 Jan. 2012. .

"Barred Owl." Science Museum of Minnesota. Warner Nature Center. 25 Jan. 2012.

Malok, Andre. "Snowy Owl Takes up Residence at Merrill Creek Reservoir in Warren County." NJ.com. The Star Ledger, 6 Jan. 2012. 26 Jan. 2012.    ledger/2012/01/snowy_owl_takes_up_residence_a.html

Thoreau, Henry David. Walden; or, Life in the Woods. New York: Dover Publications, 1995.

Vanner, Michael. The Encyclopedia of North American Birds. Barnes and Noble, 2003.

“What Is an Owl Pellet?” Owl Pellets. 25 Jan. 2012.

A Long Winter's Nap

When the air grows icy and winter sets in, New Jersey’s animals have many ways of coping with colder temperatures and a lack of food.  Some, like birds, migrate.  Warblers and swallows fly south to find active insects, sparrows fly south to find uncovered seeds, and water birds fly south to find open water.  Other animals, like insects, spiders, reptiles, and amphibians will also migrate—deeper into the earth.  Salamanders and earth worms will burrow beneath leaf litter and toads will burrow under the soil, below the frost line.  Snow provides an insulating layer for these animals.

Some animals grow warm, thick winter coats, such as white-tail deer, whose winter coats are made of hollow hairs to trap extra body heat.  Birds that stick around for the winter, such as goldfinches and redpolls, grow more feathers and fluff them for insulation.  Animals like deer, birds, squirrels, rabbits, and beavers stay active during the cold months.  Even in the coldest places, staying active will keep an animal alive through the winter.  For example, the arctic fox in the Arctic and the emperor penguin in the Antarctic will survive the cold because of their appropriate insulation, considerable energy reserves, and ability to successfully compete for continuing food sources.

Several of New Jersey’s animals have another adaptation for surviving the cold winter months, however.  They will either enter a state of torpor or prolonged torpor, otherwise known as hibernation.  To enter into a state of torpor is to enter into a state of hypothermia, accompanied by inactivity and lowered metabolism, body temperature, and heart rate.  There is a fall in oxygen consumption and breathing rates and a restriction of blood flow to the main organs.  Why would an animal adapt to enter such a state?  This type of deep sleep is a form of energy conservation.  Animals that live in cold climates develop such sleeping patterns when food gathering becomes more difficult and it would take too much energy and body heat to search for food.

Torpor is driven by ambient temperature and food availability.  Many of New Jersey’s mammals, such as the black bear, chipmunk, raccoon, and skunk, enter states of torpor to make it through the cold months.  To prepare for the winter, black bears accumulate body fat throughout the summer and autumn.  In late fall, when food becomes scarce, they make their dens and enter them for the winter.  Black bears lose about 25 percent of their body weight during the winter, but they stay in good physical condition, and they will awaken and leave their dens periodically, especially if food is available.  Female black bears give birth during the winter, and their fat stores from the summer and autumn provide enough nourishment to suckle their young.  Even in the arctic and sub-arctic, bears are not true hibernators.  They will simply experience seasonal lethargy and periods of torpor to get through the winter.

Animals that maintain very high metabolic rates will often go into daily torpor.  This allows them to sleep through times when it is difficult to find food.  For example, bats will enter torpor during the day, when it is difficult to find insects.  Their bodies therefore use less energy, and food will last longer in their bodies.  They will wake up again when it is time to search for more food.  Bats take about two hours to reduce their metabolic rates, drop their body temperatures, and enter into a state of torpor.  When they are ready to awaken, it will take about an hour.  They warm up by shivering violently and contracting their muscles.  Frogs will enter torpor during the night because nighttime air temperatures are too cool for them.  They therefore use less food and energy to keep warm during the night.  Other animals that enter daily torpor include hummingbirds, swifts, nightjars, nighthawks, poor-wills, and goatsuckers.  Doves and pigeons enter a shallow state of torpor when they are deprived of food.

Hibernation is a sustained state of torpor.  Entry into and exit from hibernation are governed both by internal signals such as hormone changes and external cues such as day length and temperature.  Whether in a state of torpor or a state of hibernation, animals have the ability to wake spontaneously, despite the temperature.  Animals hibernate for several months, though they will occasionally awaken throughout the winter.  They will remain in a state of deep torpor for several weeks at a time, and then awaken for several hours before entering into a deep state of torpor again.  These short periods of arousal and activity may serve to maintain organs, tissues, and cells; animals are susceptible to parasitic infections while hibernating, so waking up occasionally may boost their immune systems.

Very few of New Jersey’s mammals are true hibernators.  Only the jumping mouse, woodchuck (or groundhog), and little brown bat hibernate through the winter.  For these animals, foraging for food and maintaining their normal core body temperatures during the winter months are energetically too costly.  Like animals who enter short periods of torpor during the winter, animals that enter hibernation will also prepare in the summer and autumn by eating more food than usual and building fat stores.  An animal in hibernation will not lose any of its muscle; it will just lose its stored body fat.  The longer the animal is in a deep state of torpor, the thicker its layer of fat will be.  When hibernating animals awaken, they will be much thinner, but they will have maintained their muscle.  As in torpor, hibernating animals slow their heartbeat, breathing, and metabolism.  Animals that hibernate drop their body temperatures lower than those who enter torpor.  Their body temperatures will drop so low that they will match that of the ambient air temperature!  But hibernating animals protect themselves in sealed dens that remain above freezing temperature because of insulation and geothermal heating.  During the depth of winter, the length of time that animals stay in their deep state of torpor lengthens.  As spring comes closer, the periods of torpor decrease and the periods of activity increase until one day, arousal marks the end of hibernation.  Temperature and the instinct to mate are other factors that call animals out of hibernation.  

The groundhog doubles in weight from May to September to prepare for a four to five month period of hibernation.  On Groundhog Day, when we call the groundhog out of its den and look for its shadow, we are awakening an animal deep in sleep.  Depending on factors such as temperature and photoperiod, the groundhog may reenter a state of prolonged torpor to make it through the remaining winter months.  As humans, though, we don’t have that option; we will have to continue emerging from the warm dens of our beds, bundling up, and staying active throughout the cold season.

              

References:

"Animals at the Extremes: Hibernation and Torpor." Open Learn: The Open University. Web. 27 Dec. 2011. http://openlearn.open.ac.uk/mod/oucontent/view.php?id=398616&direct=1.

Harris, Steve. "How to Tell Torpor from Hibernation." Discover Wildlife | Wildlife and Photography at Its Best with BBC Wildlife Magazine. 15 July 2010. Web. 27 Dec. 2011. http://www.discoverwildlife.com/british-wildlife/how-tell-torpor-hibernation.

"Hibernation." ThinkQuest. Web. 27 Dec. 2011. http://library.thinkquest.org/TQ0312800/hibernate.htm.

"Mammalian Hibernation." University of Calgary, 26 Feb. 1999. Web. 27 Dec. 2011.  http://people.ucalgary.ca/~kmuldrew/cryo_course/cryo_chap12_1.html.

"Torpor." ThinkQuest. Web. 27 Dec. 2011. http://library.thinkquest.org/TQ0312800/torpor.htm.

The People of the Stony Country

Knowing Sussex County the way we know it today makes it difficult to visualize the indigenous people who once lived in this area, but if you’ve ever visited the museum at Space Farms and seen its large arrowhead collection, you know that this area was once populated by the Lenni Lenape.  Also referred to simply as the Lenape, which means “true or native men, or common people,” these people occupied “Lenapehoking,” or “the land of the Lenape.”

The Lenape are divided into three sub-groups who speak different dialects of the Delaware Language: the Minsi or Munsee, “the people of the stony country,” who occupied Sussex County and other parts of northwestern New Jersey and the highlands of eastern Pennsylvania; the Unami, “people from down river,” who occupied the Piedmont province of New Jersey south of the Raritan River; and the Unalachtigo, “the people who live near the ocean,” who occupied the coastal plain.  “Lenape” is a word from the Unami dialect, and linguists determined that the Lenape are descended from Algonkian-speaking people.  The Minsi people acted as a buffer between the Mohawk people to the north and the other Lenape groups to the south.  Their main village, Minisink, was along the banks of the Delaware River in Sussex County.  Their totem was the wolf.

There were indigenous people living in this part of New Jersey before the Lenape developed the technology and culture that we think of today.  At the end of the last ice age, about 12,000 years ago, Paleo-Indians arrived, living as small nomadic bands of hunters.  As time went on, and as the climate warmed, people began to seek out additional food sources, such as fish, shellfish, and wild vegetables.  As forests became dominated by oak trees, acorns provided an additional food source for humans; acorns also brought deer and wild turkey to the region.  About 2,000 years before European arrival, the people began to develop new hunting tools, woodworking tools, stone cooking pots, and pottery.  Bows and arrows, dugout canoes, tobacco pipes, and storage jars were also created.  Early crops included plants such as sunflower, pumpkin, squash, and gourds.

From year 1000 to 1350, archaeologists can more specifically identify the culture of the indigenous people, and it is from this point on that the people are referred to as the Lenape.  Their housing structures, known as wigwams, were round-edged, oval-shaped shelters made of sapling frames with coverings of chestnut, elm, and cedar bark shingles.  The houses had storage pits to hold dried fish and meat, squash, maize, beans, native artichoke, and pumpkins, indicating that gardening was becoming a more important part of the culture.  Arrowheads and fishing tools from this period show that hunting and fishing were still significant methods of food procurement.

Walking through the forest today, you will come across many of the wild plants that the Lenape gathered.  Maple syrup was extracted from maple trees; tea and medicine were made from the root of the sassafras tree; crab apples, plums, grapes, persimmons, mulberries, strawberries, blackberries, and cranberries were gathered; acorns were boiled and then ground into a pulpy flour; chestnuts, walnuts, hickory nuts, and hazel nuts were eaten; and hemlock and pine needles were used to make tea.  Swamp potato, jack-in-the-pulpit, wild morning glory, American licorice, wild ginger, cattail flag, ginseng, and the American lotus were also food sources.  Additionally, bark from trees such as the elm and basswood were used to weave mats and baskets, as well as to aid in the construction of wigwams.  Many flowers, roots, barks, and sap were used to make a variety of medicines, and specific people in the community served as healers and were familiar with these plants.  In addition to curing illnesses, these older men and women also made weather forecasts, prepared charms for hunters, and made prophecies.

The first European explorer to describe the Lenape was Giovanni da Verrazano, who wrote in 1524:

“These people are the most beautiful and have the most civil customs that we have found on this voyage.  They are taller than we are; they are a bronze color, some tending more toward whiteness, others to a tawny color; the face is clear-cut; the hair is long and black, and they take great pains to decorate it; the eyes are black and alert, and their manner of the   ancients…they have all the proportions belonging to any well-built men.  Their women are just as shapely and beautiful; very gracious, of attractive manner and pleasant appearance” (quoted in Bertland et al., 1975, p. 30).

Though relations between European settlers at this time were peaceful, such harmony would not last.  Less than a century later, when more Europeans—particularly Dutch, Swedish, and English settlers—arrived in North America, the Lenape began to feel the effects of disease, loss of land and natural resources, and negative encounters.  By the beginning of the 18^th century, the population throughout Lenapehoking was estimated at about 2,400 to 3,000 as a result of disease and colonial wars.  Due to these pressures, the Lenape began to migrate west, though they were sometimes forced to even more distant locations by the Iroquois.  The Lenape were eventually displaced as far away as Texas, Oklahoma, Wisconsin, and Canada.  Despite these hardships, the legacy of the Lenape remains.  Next time you head into the woods or relax along the banks of the Delaware, imagine these people who once lived in our forests; when you see acorns littering the ground in fall or a white-tailed deer bounding across the road, imagine the abundant resources available to these eastern woodland people and the way they lived amongst nature.

References:

Bertland, D. N., Valence, P. M., & Woodling, R. J. (1975). The Minisink: a chronicle of one of America’s first and last frontiers. Four-County Task Force on the Tocks Island Dam.

Kraft, H. C. (1986). The Lenape: archaeology, history, and ethnography. Newark, NJ: New Jersey Historical Society.

Orr, D. G., & Campana, D. V. (1991). The people of Minisink: papers from the 1989 Delaware Water Gap Symposium. Philadelphia, PA: National Park Service, Mid-Atlantic Region.

Mud Daubers

Whenever I would look up at the ceiling of my porch during the summer, I would see wasp nests: long, hollow cylinders made of mud, dried almost white, placed next to each other like the pipes of an organ. I never thought to question who made these nests until I read Bernd Heinrich’s Summer World: A Season of Bounty. Reading his account of dissecting the nests of the organ pipe mud dauber fascinated me.


This is how the wasps reproduce. They build their pipe-like nests with mud. The nest will be closed at the top but left open at the bottom. The female wasp will find a spider, then sting the spider in order to paralyze it but not kill it. She will take the spider up into the nest. She will stuff several more spiders into the very top of the nest before laying a single egg, then sealing off the compartment with a mud layer. The wasp will then add on to the nest, making it longer, adding more spiders, laying an egg, sealing off the compartment, and continuing. She will add more tubes next to the first and repeat the same process. The egg, when it becomes a larva, will then feed on the comatose spiders as it grows. When the larva has reached a size of about ¾ of an inch, it will spin a cocoon and remain protected inside the nest for the winter. The following summer, the adult mud dauber will emerge from its cocoon and then chew through the mud wall of the nest. Though the wasp larva specializes on spiders, the adult loses its taste for such meat and instead feeds primarily on flower nectar.

As soon as I read Heinrich’s description of the wasps, I immediately went to look on the ceiling of my porch where I had seen the nests so many times before. As I expected, there was a small nest there. While a strong urge exists to take down the nest and dissect it to see the crumpled spiders inside and the wasps growing inside their cocoons, I will leave them be. Maybe in the spring I will pay more attention and look for the female wasps carefully carrying spiders to the porch ceiling.

Coincidence

I had a good bird day today.

I saw an American Goldfinch perched on a tall stem of grass on my drive to work. (I’ve been seeing them more and more lately, most often on my drives to and from work, but occasionally one will pause on the sand near the edge of the lake where I lifeguard.) While I was sitting on the stand, across the lake a Bald Eagle—the first one I’ve seen this summer—swooped down to grab a fish out of the water, then flew to the northwest edge of the lake. I only briefly glimpsed its white head, but its white tail caught the sun’s light as it flew away. Another bird I’ve never seen before (which makes it harder for me to identify—was it a warbler? a female tanager?) landed on the sand in front of the lake before flying into a tree on the lake’s edge. (It’s even harder to identify the birds that make appearances at the lake because I’m supposed to be watching the people in the water, not the birds nearby.)

But the best was the Eastern Bluebird that I saw as soon as I arrived at the lake. I was sitting in my car, listening to my music while waiting for another guard to arrive with a key to the building. As one song was ending on my iPod shuffle, a Bluebird flew toward me and landed a few parking spaces away in the otherwise empty parking lot. The sun caught the blue in its wings; it was striking to me how blue this bird was. I’ve seen Bluebirds before, and several at the park where I work, but I had never seen one so brilliantly blue. I was contemplating this, and watching the bird as it tried to eat whatever lay in front of it, when the next song began on my shuffle. “One morning when I was riding in my old pick-up truck, a beautiful bluebird came flying down…” Of some 6,000 songs on my iPod, what are the chances that this song—one I actually did not know existed before this morning—came on, just as I was watching the very same bird? Neil Young goes on to sing about the “beautiful bluebird” and how he has “never seen that blue before.” I watched the bluebird in the parking lot for the duration of the song, marveling at the coincidence and the beauty of both the bird and the song, until it flew away, just as the song ended, as one of my coworkers arrived.


Photo from allaboutbirds.org
As I was watching the Bluebird, I remembered an ornithologist I knew while in Australia telling me that North American birds were “boring”—I assumed he meant that they were not as large and colorful as Australia’s rainforest birds. With our many drab-colored birds, I didn’t think very much about his comment. But after watching the royal-blue bird today, the bright yellow goldfinch, the olive/yellow unidentified bird, and the magnificent eagle, I wondered how he could have said such a thing. In behavior and appearance, these birds were anything but boring. They were beautiful—it was a good bird day.