YORK - After a long and very white winter, at last it feels like we are actually getting closer to the annual explosion of green that will soon grace our local backyards and forests.

But even before the crocuses emerge and new buds start popping on the trees, it's exciting to know that there's quite a lot going on underneath the snow and ice in preparation for the longer, warmer days ahead. Quietly waiting in our woods are dozens of vernal pool wetlands that are soon to become temporary nurseries for thousands of animals - some that you can only see with a microscope! All's pretty quiet now, but in just a short time, choruses of wood frogs and spring peepers will join the melodies of songbirds returning to their nesting sites, and these vernal pools will be teeming with life.

We are lucky to have so many of these little natural laboratories available to us for observation here in our community.

Spring is a wonderful time to get reconnected with the natural world around us.

This month's feature will introduce the uninitiated to vernal pools, how important they are to our ecosystem and how you can enjoy and help protect them for the future. We want to extend a special "thank you" to our friends at White Pine Programs and Mt. Agamenticus Conservation for their contributions to our column this season. We look forward to hearing from our readers and seeing you out and about enjoying the "Nature of York"...

WHAT ARE VERNAL POOLS?

Vernal pools are seasonal pools that typically fill up with water in the spring and early summer, and dry up for the rest of the year. As temporary habitats, vernal pools cannot support fish life. Without the presence of fish as major predators, the pools provide successful woodland breeding locations for wood frogs and mole salamanders.

York is fortunate to have many woodland vernal pools brimming with life in the spring as integral parts of our local environment. Due to its unique topography and underlying bedrock, the greater Mount Agamenticus region contains a treasure-trove of vernal pools.  This area in southern York County has the highest concentration of pocket wetlands and vernal pools in the state and one of the highest in New England. The density of these wetlands make the region particularly important for amphibians and several rare turtle species including Blandings and spotted turtles, as they provide ideal foraging and breeding habitat. 

In recognition of the tremendous value of vernal pools, the State of Maine now legally protects vernal pools that qualify as "significant." Not only is a pool itself important, for reasons you will see as you read on, but the shoreline area extending 750 feet around the pool provides equally important habitat. Species breeding in a vernal pool will venture up to one-third of a mile from it to burrow under logs and leaf litter where they spend most of the year. In fact, most pool-breeding amphibians spend less than one month in the pool, with the rest of the year spent in the surrounding buffer zone.

One New England-based study found that not only do vernal pools ensure the survival of amphibian populations, they help supply food for the entire forest ecosystem. After leaving the vernal pool, wood frogs and salamanders become food for snakes, turtles, mammals and other inhabitants of the forested ecosystem. Researchers studying one pool found that the collective weight (or biomass) of vernal pool-breeding amphibians was greater than the biomass of all breeding birds and small mammals combined in a surrounding 50-acre area!

"BIG NIGHT"

Each spring, when conditions are just right, thousands of frogs and salamanders emerge from hibernation to migrate to the vernal pool of their birth to mate and spawn. Typically, when the temperature rises above 42 degrees Fahrenheit and rain begins to fall during the day and continues late into the night, these amphibians migrate. The moisture is necessary to keep them wet as they journey to their pool, crossing roads and other obstacles in their path. Perfect conditions cause massive migrations that can occur on a single evening, referred to as "Big Night."

Big Night is an exciting time to venture out and get a look at these normally unseen creatures. Some folks come out for Big Night just to assist animals crossing roads.

Massachusetts has installed very successful amphibian crossing tunnels at migratory hot-spots in locations across the state. Researchers and volunteers erect drift fencing to help funnel animals toward the tunnels that run underneath busy roadways and help them safely reach vernal pools on the other side. For more information on these efforts, visit www.fhwa.dot.gov/environment/wildlifecrossings/salamand.htm.

HOW TO HANDLE AMPHIBIANS

If you go out for Big Night, or decide to handle an amphibian on another lucky occasion, there are some basic things to know so that you can pick them up safely, without harm to these sensitive animals. The first thing to know is that anything you have on your hands will be absorbed into their skin. So covering your hands with antibacterial lotion will be a disaster! Really, no soap or lotion is good for them to come into contact with. The very best way to prepare to hold a salamander or frog is to rub your hands with soil from the area and make sure they are moist.

Salamanders, in particular, will be moving slowly in this cold temperature. The simple act of holding one on your palm will begin to warm up the animal, and it will start moving faster. You must be careful not to accidentally drop it. The best posture for you is to get low to the ground so if it does wriggle away, it doesn't have far to drop.

Hold the salamander just long enough to relocate it safely across the road, and release it. Keep in mind that your safety is important while you are out, and a headlamp or reflective clothing is a must!

IMPACTS OF THE OBSERVER

There is a delicate balance between experiencing nature and impacting it. Any time you are out enjoying the natural environment, tread lightly. Vernal pool habitats are sensitive as are the species that rely on them. Bringing pets or large groups of people to one small area can have a negative impact on that area. Certainly, a dog tearing through a vernal pool filled with egg masses can be very destructive.

When exploring wildlife habitat on Mt. A, Mount Agamenticus Conservation Coordinator Robin Stanley states that there are ways visitors can reduce their impact to trails, streams and vernal pools.

"To maintain the quality of streams and wetlands and to reduce the work to repair these areas, in general it is best to visit the area when the trails are dry," she noted. "To further protect vernal pools, be sure to keep dogs leashed and out of wet areas - especially in the spring." 

Since trail and water quality degradation is most severe in the spring and after heavy rainfall when the topsoil becomes saturated, it is especially important to be mindful when exploring vernal pools. Soil is disturbed by traffic creating channeling and runoff leading to erosion and the sedimentation of sensitive streams and vernal pools. Stanley also encourages visitors on Mt. A to "familiarize themselves with trail use designations and to control noise levels and speed. This will help to minimize stress on wildlife, reduce conflicts with other visitors who may be there for a different experience, and ensure continued access to the land." 

As always in your travels, be mindful of your impact while you enjoy these beautiful places.

DO YOU HAVE A SIGNIFICANT VERNAL POOL?

The state of Maine began to legally protect "significant vernal pool habitat" in September, under the Natural Resources Protection Act. If a pool is determined to be significant, then the pool and a 250 foot buffer of the critical terrestrial habitat surrounding it are considered a protected resource. Any disturbance of the area now requires a state permit.

According to the state, a pool qualifies as "significant" if it has at least 20 spotted salamander egg masses, 10 blue-spotted salamander egg masses or 40 wood frog egg masses. The presence of an endangered or threatened species using the pool -such as a spotted turtle, Blandings turtle, ringed boghaunter dragonfly, ribbon snake, wood turtle or four-toed salamander - or the presence of fairy shrimp also qualifies the pool for protection.

The state website has a data collection form that can be filled out and submitted with photographs to help document a significant vernal pool, but a trained biologist needs to make the final assessment. Contact the Maine Department of Inland Fisheries and Wildlife for more information.

On the internet

http://www.pwrc.usgs.gov/frogquiz - Patuxent Wildlife Research Center in Maryland has a section of their website dedicated to frog identification by their vocalizations. You can listen to recordings of different frog sounds based on species, or by a state list.

http://www.vernalpool.org/ - This is a comprehensive website from the Vernal Pool Association in Massachusetts. It is a wealth of information, and particularly valuable resource for teachers.

http://www.vernalpool.org/ed-st-01.htm - Download signs to laminate and post near amphibian crossing zones in your neighborhood!

http://maine.gov/dep/ - Visit the state of Maine website for details on "significant vernal pools" including how to identify one on your property and the specifics of its protection.

http://monarchbfly.com/2007/03/27/migration/ - Excellent blog on the spotted salamander migration in New York state, including a terrific short video clip of a "congress" of salamanders!

http://vernalpools.rtpi.org/account/322 - A project of the Roger Tory Peterson Institute, this website has photographs of amphibians you may see in a vernal pool, along with photos of their larval forms and egg masses - great for identification.

Vernal Pool Yahoo Group: Subscribe by sending an e-mail to: vernalpool-subscribe@yahoogroups.com

Recommended reading

For adults, check out:

Vernal Pools: Natural History and Conservation, by Elizabeth A., Ph.D. Colburn

Science and Conservation of Vernal Pools in Northeastern North America, by Aram J. K. Calhoun, Phillip G. DeMaynadier

http://mainegov-images.informe.org/ Forestry Habitat Management Guidelines for Vernal Pool Wildlife

For Kids:

Frog Heaven: Ecology of a Vernal Pool, by Doug Wechsler (Illustrator)

In 2003, William and Mary McFeely donated a 38-acre conservation easement with the express purpose to protect the property as "forever wild" and to allow for low-impact, non-motorized public access.

People are invited to visit this pristine preserve and walk the loop trail which passes through upland forest, wetlands and scenic rock outcroppings along Marsh Brook in Cape Neddick.

Last spring, fifth graders from York Middle School explored the McFeely Preserve to scout out a few of its vernal pools. The information they gathered is being used by the York Land Trust to document sensitive areas on the property and help form management decisions for the future.

"We went out to the Preserve a bunch of times - in the rain and the snow at first, looking for landmarks to map what we found," reported Sean Horigan, now in the sixth grade, "it was cold and wet."

 small group of students met for a reunion pizza party to reminisce over their experiences last year in Margot Simonds' and Kelly Renfrew's classes.

"A vernal pool is like the forest floor, only flooded," described Bridjet Ely.

All of the students recalled their experience in great detail, and retained a surprising amount of knowledge of vernal pool dynamics. They remembered that the protected buffer zone around a vernal pool in Maine is 250 feet.

"They were starting construction of a house or something across the street," said Horigan, "that would have a big impact on these vernal pools if it were closer to them, where we were."

For repeated visits to the property in April and May, the students searched the vernal pools and surrounding areas for frogs, salamanders and other wildlife.

"We all had different jobs," Kelley Francis said, listing them, "drawing pools, mapping, GPS, taking pictures, and using buckets to scoop up water and see what's in it. If we found something, we took notes then replaced it exactly where we found it."

Classmates spent time using GPS units to mark coordinates for future visits, and to easily record their findings. The most common animal they found was the red-backed salamander.

"I liked going out and seeing it better than reading about it inside," said Brynn Vessey referring to her favorite parts of the research. "The second time we went out we saw the eggs of spotted salamanders and we knew it was an actual vernal pool."

By the second visit the amphibians had migrated to the McFeely pools.

"They need humid rain," added Chris O'Connor, as the group described the perfect conditions of temperature and seasonal rain needed for a successful migration.

By the third visit, the eggs were fewer. Carlie Martin theorizes that it was not the eggs hatching, but because of the predacious caddis fly larva they found in the same pools, "they were all over the eggs, eating them."

This year, Simonds and Renfrew are taking their classes back to York Land Trust properties to continue their vernal pool studies.

"The experience last year was such a rich one for the students," explains Simonds, "I hope we can continue to work with York Land Trust this year and for many years to come."

She cites the in-our-own-backyard approach to learning as part of its success.

"The enthusiasm and learning that took place last year during our Vernal Pool Project was directly connected to the fact that the study involved our own community.  Last year's students have asked to go again this year.  Hands-on learning combined with providing a genuine service to our community and at the same time being outside and looking for egg masses and amphibians in the water and mud........what could be better than that?"

TO MCFEELY PRESERVE

Take Logging Road northwest for 1.5 mile, from Route 1, half-mile past Flo's Hot Dog stand. Marsh Brook Road begins across from the intersection with Clay Hill Road. A small turnout is on the right. Continue in half-mile for parking.

CAPE NEDDICK - Vernal pools are formed in depressions in our forests.

In the Northeast, a vernal pool fills with water because of the rising water table of fall and winter, or with the melting water from the spring thaw of winter snow and ice. It is an important ecosystem of our forests, and without it our entire ecosystem would not be complete.

Several species of amphibians are obligate vernal pool species, which means that they need to use a vernal pool for various parts of their life cycles. Because vernal pools are a temporary habitat (only wet for three seasons), the species associated with vernal pools very cleverly only use them for some or part of their life cycles. The other parts of their life cycles are spent out and about in other habitats, playing an important role in those ecosystems as well, where other plants and animals interact with and sometimes depend on them for food or other reasons. Thus the vernal pools are connected to many of our other forest habitats, as well as the larger ecosystem that we call New England. The loss of vernal pools and their species would mean a local loss of amphibian species, a decrease in biodiversity, and a decline in food available for many other animals that live around them. But what about us?

Don't worry, we are connected too. Besides bringing us joy through observation, a beautiful spring chorus and the fact that they have been here longer than us, these species and microhabitats unknowingly help to keep our air and water clean. Because the vernal pools are filled through drainage of the water table, what we put down our drains at home, what leaks out of our cars, what we put on our lawns and what we put on the roads among other things can eventually make its way to our vernal pools. 

WHO GOES THERE?

Let's take a look at who is using these pools and what their roles are.

Because of its unique environment, many rare species are able to thrive here. Believe it or not, there is an entire ecosystem thriving inside of a healthy vernal pool. To clarify, there are obligate vernal pool species (those that are unable to complete their life cycles without vernal pools), and facultative vernal pool species (those that can use vernal pools to complete their life cycles, but are able to use other water bodies as well).

The absence of fish in vernal pools (because it dries up in the summer) allows for a rich diversity of amphibians and invertebrates found here. Among obligate amphibians are the wood frog, spotted salamander and the blue-spotted salamander.

Obligate invertebrates include the fairy shrimp. Facultative species include the spotted turtle, Blanding's turtle, painted turtle, wood turtle, snapping turtle, Eastern ribbonsnake, Northern watersnake, common gartersnake, spring peeper, gray treefrog, American toad, Fowler's toad, green frog, pickerel frog, leopard frog, bull frog, red-spotted newt, dragonfly larvae, mosquitoes, damselfly larvae, water boatmen, backswimmer and clam shrimp, and many more!

Mallards, wood ducks, raccoons, egrets, hawks, warblers, bats and others use vernal pools as a seasonal source of food and water.

Threats to vernal pools include housing development, roads, or a loss of tree cover in surrounding habitat. This can lead to decreased shading, rising water temperatures, decreased oxygen content, increased evaporation, and shorter flooding cycles, impacting the delicate creatures that call the pool home. 

A YEAR IN THE LIFE

Let's take a look at how one particular species may use a vernal pool throughout the year. We'll focus on the spotted turtle.

At 7 to 14 years old, if she manages to survive all the hazards she will face in her "childhood," a female is finally ready to lay eggs. In May or June she will leave her wetland or vernal pool and find a nice sunny, moist spot with well-drained soil in which to lay her eggs. Using her hind feet she will dig a nest and lay one to eight eggs in her clutch. The turtles will hatch in August or September, but most likely will remain in the nest until spring. After laying the eggs she will travel back to her wetland or vernal pool area. Moving on land can be very dangerous for a spotted turtle as they are vulnerable to clever raccoons. The pools offer an escape route as they are able to dive down quickly and hide under leaves and other vegetation.

In the fall the spotted will make her way back to her hibernacula, which occurs in a variety of wetland habitats including vernal pools. Her winter home may be a structure made from clumps of cattails, grasses and sedges, or submerged cavities created by rocks and tree roots. She also may choose a soft winter den inside of elevated mats of sphagnum moss. Cozy!

She will fuel up for hibernation with everything her pool has to offer. Algae, water lily seeds, worms, mollusks, crustaceans, adult and larval insects and amphibian eggs provide the perfect fall feast. As the temperatures start to drop, and fall turns to winter, her body processes will slow down and she will remain in her hibernacula until spring.

Emergence in Maine usually occurs from late March to May, depending on the temperatures. She may very likely be awakened by her neighbors the wood frogs who are typically the first early risers to emerge. She will be slow to wake up, and probably won't start to feel hungry until water temperatures reach 15 degrees Celsius. She will spend the spring feeding in her vernal pool, and if it dries up she will venture to another one close by.

She will find a mate early in spring, mating in the water. In May and June she will hopefully lay another clutch and do it all over again! 

WHAT CAN WE DO?

There are several actions we can take to help protect vernal pools, on small and large scales. Here are a few ides:

• Work with local or government conservation groups to document and identify vernal pools in your area. Become an advocate for stronger laws against development in vernal pool areas.
• Don't touch that brush! Leave trees, bushes, logs, dead trees and brush in and around vernal pool habitat. It provides shelter and locations for egg masses.
• Avoid adding additional matter to the pool such as lawn clippings or leaves, even in the dry season.
• Leave a natural vegetation buffer around the pool; 100 feet can protect water quality, but 300 feet will ensure better survival of species that use these pools.
• Avoid digging, building, or other activities around the pool that can alter the flow of groundwater and thus disrupt the natural flooding cycle.
• Be aware of proposed development areas and do not support those that would fill in or disrupt these important habitats.