Monthly Archives: April 2012

Be on the watch for turtles as we move into spring and summer…

Photos

Turltes1.jpg

Contributed

Don Lyman holds a large snapping turtle at  Lowell-Dracut-Tyngsboro State Forest.

Turltes1.jpg
Turtles3.jpg
By Don Lyman/DAILY NEWS  CORRESPONDENT
Posted Jun  01, 2010 @ 10:00 AM
PrintComment

Over the next month or so, from the end of May until the end of June, female  turtles will leave their watery hangouts and trek overland in search of a spot  to lay their eggs.

Massachusetts has 10 species of native turtles — painted, snapping, musk,  red-bellied, bog, spotted, Blanding’s, wood, box and diamondback terrapins (and  one exotic species, the red-eared slider). Except for the box turtle, which is a  terrestrial or land turtle, and the diamondback terrapin, which lives in salt  marshes, all of our turtles live in fresh water environments.

From diminutive 4-inch-long musk turtles to 60-pound snapping turtles, if  you live or work near a pond, stream, swamp or other wetland, you’re likely to  see one of these reptiles crossing a road or parking lot, or digging a nest hole  in an open field or vacant lot, or even in your yard.

Turtle nests consist of a hole in the ground, which female turtles dig with  their hind feet. They tend to choose patches of bare soil, which is easy to dig  in, in open areas like fields or yards where the nests will get plenty of  sunlight to incubate the eggs. For example, a conservation officer for a town  north of Boston told me recently that Blanding’s turtles, which are a threatened  species in Massachusetts, like to nest in the sandy soil on the town’s soccer  field. During nesting season the part of the soccer field where the turtles dig  their nests has to be cordoned off until the baby turtles hatch in late August  and early September.

Smaller turtles, like bog or musk turtles, may only lay four or five eggs.  Bigger turtles, like Blanding’s or snapping turtles, may lay a dozen or more.  After she’s finished laying her eggs, the female turtle fills in the nest hole  and covers the eggs by pushing the loose soil she’s excavated back into the hole  with her hind feet. The eggs usually hatch anywhere from two to three months  after being laid.

Interestingly, the sex of the hatchlings is determined by temperature, with  warmer soil temperatures typically producing female offspring and cooler soil  temp’s producing male offspring, although this can vary depending on the  species.

Threats to turtle eggs include mammals like raccoons, skunks, opossums and  rats, which will dig up the nests and eat the eggs, according to Kerry Muldoon,  Conservation Commission biologist for the city of New Bedford. Muldoon adds that  even plants can pose a threat to turtle eggs. She says the roots of beach grass  and saltmarsh cordgrass can penetrate and destroy the eggs of diamondback  terrapins, which she studied while in graduate school. Hatchling turtles  likewise fall prey to a variety of animals including mammals, birds and even  ants.

Many adult turtles are hit by cars as they cross roads in search of nest  sites or when they attempt to nest in open areas along the edges of roads.  Turtles also sometimes nest in the open, sandy and gravelly soil next to  railroad tracks where they may be hit by trains or become trapped between the  rails. Biologist Tim Beaulieu says he found about a dozen or more turtle nests  along a 100-foot section of railroad track behind a small pond while conducting  a biology survey for reptiles and amphibians in a suburban area west of Boston a  couple of years ago. Unfortunately, Beaulieu said, all the nests had been  destroyed by predators. Additionally, Beaulieu said he found the remains of  several adult painted and snapping turtles trapped between the rails.

Turtle eggs and hatchlings have a high mortality rate and only a small  percentage of turtles ever reach adulthood. Because of this low survival rate,  says the Massachusetts Division of Fisheries and Wildlife website on turtles,  “…a turtle must live for many years and reproduce many times in order to  replace themselves in their population. Losing any adult turtles, and  particularly adult females, is a serious problem that can tragically lead to the  eventual local extinction of a population.”

The Massachusetts Division of Fisheries and Wildlife’s Natural Heritage and  Endangered Species Program is working with the Massachusetts Department of  Transportation on a new program called the Turtle Roadkill Monitoring Project to  locate turtle roadkill hotspots. Its goal is to identify and monitor problem  road crossing sites for turtles. The program is asking for public’s help to  identify potential turtle roadkill hotspots in your town, working to confirm the  spots with project coordinators, then help conduct road surveys at these sites  during designated time periods in May and June.

In addition to roadkill hotspots, Mass. Fisheries and Wildlife and the  Turtle Conservation Project are asking the public to submit information on  locations where multiple turtles nest, as well as to report sightings of  individual turtles.

If you should find a female turtle nesting in your yard, Mass. Fisheries and  Wildlife says the best thing to do is to keep people and animals away from the  area until she’s done nesting, which can take several hours. Also, remember that  turtles can deliver a painful bite and, in the case of large snapping turtles,  can inflict serious wounds. Half a dozen of Massachusetts’ native turtle species  are state listed as endangered, threatened, or species of special concern. Other  than snapping, painted and musk turtles, it is illegal to capture and keep wild  turtles as pets in Massachusetts. It’s also important never to release  store-bought turtles into the wild, as they may transmit diseases to wild turtle  populations.

Turtles have been around since before the time of the dinosaurs and they  play an important role in the environment as predators, herbivores and prey.

“Aquatic turtles often represent a very high proportion of animal biomass in  wetlands they occupy, therefore making them very important in wetland food  webs,” says Dr. Hal Avery, a biology professor and turtle researcher at Drexel  University in Philadelphia. “Turtles occupy many trophic levels (an organism’s  feeding position in a food web),” says Avery, “from primary consumers  (herbivores) to top carnivores.”

Turtles also play an important role in limiting herbivore populations,  according to Avery, which helps maintain the stability of entire ecosystems and  ecological communities. “For example,” says Avery, “without diamondback  terrapins, Spartina (the dominant salt marsh plant) salt marshes would be  overgrazed and lost to mollusc grazers.”

Avery, his colleague professor Jim Spotila and other researchers from Drexel  University, in conjunction with volunteers coordinated through the nonprofit  organization Earthwatch, have been conducting a long-term research project at  New Jersey’s Barnegat Bay for several years now, studying the ecology of  diamondback terrapins and the effects of humans on these turtles. The  researchers are discovering that commercial fishing, shoreline development,  pollution, the hazards of roads and motor vehicles, and even boat noise all take  their toll on turtles.

“Because they occupy some of the most biologically diverse and productive  ecosystems in the world,” says Avery, “and because they utilize aquatic and  terrestrial habitats within these ecosystems, aquatic turtles are paramount  indicators of ecosystem function, making them important model organisms to study  in conservation biology.”

Unfortunately many species of turtles are threatened due to habitat  destruction, pollution, roads and other hazards. But research being carried out  by scientists, as well as programs like those being conducted by Mass. Fisheries  and Wildlife, and citizen involvement in turtle conservation efforts, can help  ensure that turtles will continue to be around to play their important roles in  the environment, and for future generations to observe and enjoy as part of our  natural heritage.

Don Lyman is an adjunct instructor in the Biology Department at Merrimack  College in North Andover.

Find out more:

Massachusetts Turtle Roadkill Monitoring Project:http://linkinglandscapes.info/roads/volunteer_to_monitor.html

Turtle Conservation Project: www.turtleatlas.org

Earthwatch Barnegat Bay Diamondback Terrapin Project: www.earthwatch.org/exped/avery.html

Read more: http://www.metrowestdailynews.com/news/x644095579/Be-on-the-watch-for-turtles-this-month#ixzz1tCZTIqJg

Big Sur’s Big Birds: Intersection of two conservation success stories

By DON LYMANsantacruzsentinel.com

Posted:   06/18/2011 02:04:41 PM PDT
Click photo to enlarge

Two condors take flight near Big Sur in 2010. (DON LYMAN/CONTRIBUTED PHOTO)

Last summer, while driving through Big Sur, I rounded a turn on the road where four or five large birds were circling overhead. A dozen or more cars had stopped, and people were frantically scrambling to take photos. “Oh my God,” I shouted, as I quickly pulled over. A guy with a tripod and a large camera jogged by. “Are those what I think they are,” I asked. “Yes, they are,” he replied. California condors. I had never seen a California condor before. As a biologist from the East Coast, I was thrilled.

The big birds soared out over the Pacific, then floated back above the road, looking down curiously at the crowd of humans below. Juxtaposed against the mountains, sea, and sky of Big Sur, the condors were majestic, the perfect union of bird and landscape.

As we watched the condors catch an ocean breeze and drift out of sight down the coast, I realized I had witnessed the intersection of two of the cornerstone ideas of conservation. Habitat preservation and captive breeding/reintroduction of endangered species had come together, resulting in the preservation of one of the most beautiful stretches of coastline in the world, and the rescue of a magnificent bird from extinction.

Birds near extinction

Poaching, habitat destruction, and poisoning caused a serious decline in the condors population, and by the early 1980s condors were on the verge of extinction. In 1987, the U.S. Fish and Wildlife Service decided to capture the few remaining wild birds and move them into a breeding program with a small number of captive condors. Captive-bred condors began to be released in 1992, and wild condors now inhabit several sites in California, Arizona and the Baja peninsula.

“The flock was only 27 birds in 1987,” said Joe Burnett, senior wildlife biologist and field supervisor for the Ventana Condor Restoration Program, which is run by the Ventana Wildlife Society, a nonprofit wildlife conservation organization based in Salinas. “The current condor population consists of a captive flock of 195, and a wild flock of 188. Fifty-six of those wild condors live in the Big Sur area.”

Condors are the largest flying North American land bird, and one of the rarest; but, the rationale for preserving these magnificent birds goes beyond that.

“As obligate scavengers, condors serve an important and vital role in keeping balance within the food web,” Burnett said. “The condor plight was as a direct result of human activities. Now, we are in a position to reconnect condors to the landscape.”

This is where Big Sur fits into the condor recovery program.

Big Sur has role

Stretching nearly a hundred miles along the central California coast, from the Carmel River near Monterey, south to San Carpoforo Creek, the dramatic landscape of Big Sur is natural beauty on a grand scale. The Santa Lucia Mountains rise from the vastness of the Pacific and tower thousands of feet above the winding ribbon of road known as California Highway 1. Steep rocky cliffs tumble hundreds of feet below the roadway down to the sea, where huge waves slam into giant boulders and jettison plumes of water high into the air. An assortment of wildflowers, grasses, and shrubs are scattered across the  mountain slopes, and clusters of redwood trees dot the coastline. Blue sky and blue ocean extend as far as the eye can see.

Big Sur was protected from major development by the efforts of a variety of individuals, including celebrities such as actor Clint Eastwood, and by public and private organizations such as the California State Parks Department, the U.S. Forest Service, The Big Sur Land Trust, and The Nature Conservancy. Large tracts of land in Big Sur were purchased or donated, and became off limits to development. The rugged terrain and protection from development make Big Sur a largely wild and unspoiled area that includes more than 500,000 acres of protected land.

Condors may fly up to 150 miles a day in search of food, and with such a huge area of wild land, Big Sur provides ample space for the large birds to roam. Burnett cites additional reasons that make Big Sur prime real estate for condors.

“Big Sur is a geological wonder, where mountains meet the sea, and the interaction of the wildlife within this landscape is simply spectacular.” Burnett said. “Big Sur offers condors ample food sources in the form of marine mammal carcasses, such as California sea lions and gray whales along the coast, and ample nesting sites in the coastal redwoods, plus the fact that human occupation and impact in Big Sur have been minimal and the area remains largely protected and intact for wildlife to thrive.”

Burnett adds a cautionary note about condors feeding on marine mammal carcasses, however, and acknowledges that this additional food source for coastal condors can be a double-edged sword. “Preliminary data suggests exposure to marine contaminants (DDE) may be thinning condor eggshells”, he explains. DDE is a breakdown product of DDT, the pesticide that was banned in the U.S. in 1972. Burnett says more research needs to be done to determine the potential impact of DDE on condors.

The individuals who worked to preserve Big Sur decades ago probably never imagined their efforts would someday benefit an iconic endangered species like the California condor.

“When I see a condor in Big Sur, soaring over the coast, I see a perfect natural relationship,” Burnett said. “And I still can’t believe that perfection was almost lost.”

—————————————————————————————————————————————————

Don Lyman is a biologist and adjunct instructor in the biology department at Merrimack College in North Andover, Mass. He can be reached at Donald.Lyman@merrimack.edu.

The Bay State’s Most Common Snake

My ViewDon LymanThe Salem NewsTue May 31, 2011, 05:01 AM EDT

A sure sign of spring in New England is the appearance of garter snakes.

Having spent the winter lying dormant safely below the frost line, the ubiquitous striped serpents usually emerge from their underground hiding places when the weather starts to warm in April and May.

Named for their resemblance to the colorful striped garter belts men used to wear to hold their stockings up, garter snakes are found from Canada to Costa Rica, and from coast to coast in the United States, including southeastern Alaska. There are 30 species of garter snakes, ranging in size from the 18-inch-long exiled garter snake of Mexico to the aptly named 51/2-foot-giant garter snake of California.

The eastern garter snake, the species native to Massachusetts, is typically 2 feet or so in length, but the record is slightly over 4 feet. Declared the state reptile in 2007 by then Gov. Mitt Romney, it is also the commonwealth’s most common snake, being found in a variety of habitats from fields to forests, as well as wetlands, yards and gardens. Occasionally garter snakes even show up in people’s basements, usually in spring or fall.

Garter snakes typically mate in the early spring after emerging from hibernation, and give birth to anywhere from a dozen to 40 live young from July to October. The cold-blooded reptiles remain active as long as the weather is warm, and can even be observed basking on sunny days in late October and early November, before they disappear underground again for the winter.

While most species of garter snakes are adorned with the familiar yellow stripes, some species sport fancier colors, such as the red-sided garter snake of the West Coast, and the bluestripe garter snake, which is native to the Florida panhandle. The eastern garter snakes we see in Massachusetts generally have a brownish body color with three yellow stripes — one down the middle of the back and one on either side of the snake’s body; but some eastern garters have a checkered pattern with faint or even no stripes.

Butch Brodie III, an evolutionary biologist from the University of Virginia who studies garter snakes, says it was the garter snakes’ color patterns that initially sparked his interest in them.

“I began working on garter snakes because I was fascinated with the color pattern variation in some species, especially in western North America,” says Brodie. “The problem of how variation is maintained in the face of natural selection is an old puzzle for biologists, and garter snakes seemed like a group that might offer some new answers.”

Brodie and his colleagues discovered that different color patterns are inherited along with different kinds of escape behavior.

“Snakes with stripes tend to flee from predators, because striped patterns work well with flight (the stripes create an optical illusion of the snake moving faster than he actually is),” says Brodie. “Spotted patterns don’t appear to move as fast, so snakes with those patterns have better success by hiding or fighting.”

The closely related eastern ribbon snake, also a resident of the commonwealth, is frequently confused with the garter snake. Ribbon snakes are more slender than garters, with brighter, more clearly defined yellow stripes, and are more aquatic in their behavior, often being found in the weedy habitat along the edges of ponds, streams, marshes and vernal pools, where they hunt for frogs, fish and tadpoles.

Eastern garter snakes feed on small animals like earthworms, frogs, toads, and salamanders. They will strike vigorously if threatened and may bite if handled. Like many snake species, garters also have another weapon in their self-defense arsenal — they can emit musk from glands at the base of their tail which has a strong, unpleasant odor.

The Massachusetts Division of Fisheries and Wildlife website states that the saliva of the garter snake may actually be toxic to amphibians like frogs and salamanders; and, while harmless to humans, may occasionally produce a rash.

Patrick Gregory, a biology professor who studies garter snakes at the University of Victoria in British Columbia, Canada, published an article in 2008 in the Canadian Association of Herpetologists Bulletin where he described a bite he received from a western terrestrial garter snake that produced pain, itching and swelling of his hand. The adverse effects of the bite resolved completely after a couple of days. Gregory says he’s had many bites from garter snakes that produced no ill effects.

“I think that a big part of the reaction here was due to the fact that I let the snake hang on (for about two minutes) because I wanted a picture of it biting,” says Gregory. “Ordinarily I would have separated it from my hand earlier.”

In an email interview, Professor Brodie also weighed in on the garter snake venom issue.

“There is considerable controversy over what people refer to as ‘toxic,’ and what constitutes a venom in snakes,” says Brodie. “A variety of snakes have modified glands in the mouth (known as Duvernoy’s glands) that produce secretions like saliva, some of which have effects on prey. Garter snakes have these glands, but only a few western species have been identified as having potentially toxic secretions. Eastern garter snakes are not among these.”

He added, “These secretions have not been tested on humans. The more likely explanation for a ‘rash’ after a bite is minor infection due to the bacteria that live in most animals’ mouths.”

Gregory felt that in the case of his garter snake bite the symptoms appeared too quickly (right after the bite) to be due to infection.

Another interesting phenomenon pertaining to garter snakes and toxins involves an evolutionary “arms race” between some western garter snake species and newts, a type of salamander that produces toxic skin secretions. According to Brodie, newts, including the eastern red-spotted newt, a species native to Massachusetts, possess this toxin in the skin as a protection from predators.

“The common garter snake has evolved resistance to one of the most poisonous natural toxins known, tetrodotoxin,” says Brodie. “Garter snakes, through an arms race with newts, have evolved a different form of nerve channel that resists the effects of this poison. A garter snake from some parts of the western U.S. can safely ingest an amount of toxin that would kill more than 20 humans. We’re just now learning about eastern garter snakes, but they appear to have the same kind of resistance in some places.”

It should also be noted that newts are not toxic to people or animals unless their toxins are ingested or if their skin secretions come into contact with cuts or mucous membranes. Hand-washing after handling a newt should be sufficient to remove any toxins from the skin.

—————————————————————————————————————————————————

Biologist Tim Beaulieu with a very large eastern garter snake he found in the suburban Boston area.

—————————————————————————————————————————————————

Don Lyman is a biologist and an adjunct instructor in the biology department at Merrimack College in North Andover. He also works part time as a pharmacist at Beverly Hospital. He can be reached at Donald.Lyman@merrimack.edu.

The Mighty Mantis

Summer brings a flush of insect life to Massachusetts, some more welcome than  others. From butterflies to bees, ants to aphids, our six-legged friends are  suddenly everywhere.

Certainly one of the most interesting insects you’re likely to encounter is  the praying mantis. Named for the prayer-like position in which it holds its  front legs, the mantis is actually a formidable hunter, and the only thing it’s  likely to be praying for is its next meal. Those folded forelimbs are actually  modified raptorial graspers equipped with specialized spikes for grabbing and  holding onto prey. Mantises (or mantids, as the entire group of these insects is  known — Mantis refers to a particular genus of mantids) feed mainly on other  insects, including grasshoppers, crickets, moths and flies. They’ve even been  known to impale and eat hummingbirds! I once made the mistake of grabbing a  mantis, which promptly jabbed me with those lightning fast forelimbs, puncturing  my finger and drawing blood. Ouch! Their strong mouthparts allow them to tear  apart the exoskeletons of their insect prey.

Mantids have large compound eyes and excellent vision. They can rotate their  heads up to 180 degrees, allowing them to scan their environment for prey, as  well as potential predators, such as birds. Adult mantids also have wings and  are capable of flying.

In addition to eating other insects, the female praying mantis often eats  the male after mating. She will sometimes bite the male’s head off during  mating! Unbelievably, the body of the male mantis is able to continue mating  even after losing its head, and when mating is complete the female will finish  eating the male’s body.

Female mantises lay their eggs in autumn, attaching the batch of up to  several hundred eggs to a plant stem or leaf with a frothy liquid that hardens  into a Styrofoam-like case that protects the eggs over the winter. Baby mantids,  or nymphs, which resemble miniature adults, emerge in the spring. Mantids are  cannibalistic and often feed on their siblings after hatching. They spend the  spring and summer eating and growing to maturity before mating in the fall.  Depending on the species, most mantids live from six months to a year.

According to Dr. Piotr Naskrecki, an entomologist at the Museum of  Comparative Zoology at Harvard University, there are 2,443 species of mantids  worldwide. Thirty species occur in North America north of Mexico, four of which  are introduced species.

Read more: http://www.metrowestdailynews.com/lifestyle/gardening/x633530273/Outdoors-The-mighty-mantis#ixzz1tCOtp9kx

Owls are everywhere…

In the predawn darkness one morning last summer, through the background  noise of traffic from nearby I- 93, the distant call of what sounded like an owl  drifted in through my half open bedroom window. I strained to listen and heard  it repeat, a descending mournful cry. It was surprising, as I don’t often hear  owls around our suburban neighborhood. It called on and off for several minutes,  then stopped.

I described the sound to a friend of mine, Dr. Larry Kelts, a retired  biology professor from Merrimack College who taught ornithology there for many  years. He told me what I heard sounded like a screech owl, a 9-inch-long bird of  prey that is the most common species of owl in Massachusetts.

A few months later, while walking in the Middlesex Fells Reservation, a  heavily used swath of public conservation land that winds through several  communities just north of Boston, I was startled to see one of the screech owl’s  much larger cousins, a barred owl, staring at me at eye level, perched in a  small tree about 30 feet away. In the fading light of a December afternoon, the  nearly 2-foot-tall brownish-gray bird with large brown eyes, yellow beak, and  prominent facial disc looked every bit the spooky caricature of these nocturnal  hunters. Owls’ large eyes allow them to see better in the dark and find  potential prey. Their facial discs also help them to locate prey by focusing  sound, like that produced by a mouse rustling in the leaves on the forest floor.  The owl and I observed each other for several minutes, and I headed on my way. I  later read that many male barred owls spend the winter in urban areas, and I  recalled seeing one in a tree in Harvard Yard one evening back in the 1980s.

I sent out a group email about my unexpected encounter to several friends  and colleagues who share my interest in biology and received back a flurry of  owl stories. One friend said he and his wife occasionally hear great horned owls  calling from the woods behind their Andover home. Another said she’s seen  short-eared owls flying across the salt marshes near her apartment in Salisbury.  And a couple from the metrowest area said they hear owls calling quite often in  the pine forest behind their house.

The Mass Audubon website lists several more owl species that can be found in  Massachusetts, including barn owls, which are one of the most widely distributed  birds in the world, being found on every continent except Antarctica, long eared  owls, Massachusetts’ least common owl, and the 8-inch-long saw whet owl, the Bay  State’s smallest owl.

Read more: http://www.metrowestdailynews.com/news/x770710082/Who-s-there-Owls-are-everywhere#ixzz1tCKoo3JA