Showing posts with label vernal pools. Show all posts
Showing posts with label vernal pools. Show all posts

Friday, March 25, 2022

Spring Brings Vernal Pools and Amphibians

Vernal pool by Assenmacher, CC BY-SA 4.0, Wikimedia

It is now post-vernal equinox that signals astronomical spring but in New Jersey, it is more the meteorological spring that matters. Spring rains do create vernal pools (also known as intermittent or ephemeral ponds) which are temporary bodies of water filled by snowmelt, rain and rising groundwater for at least two consecutive months. 

Though intermittent pools and ponds may form at other times of the year, these are usually full in the spring. Most vernal pools are natural, but they might be intentionally or accidentally (sometimes via construction) man-made. They will usually dry out by mid-summer, but their importance is as breeding places for amphibians. New Jersey has an estimated 3,000 to 5,000 vernal pools, on both public and private property.

One reason that they are preferred breeding places is that they lack predator fish that would feast on eggs and larvae. Vernal pools are not without predators and they are also important for wading birds, turtles, snakes and mammals, as well as rare plants and invertebrates like fairy shrimp and dragonflies. Turtles found in New Jersey’s vernal pools include wood turtles and spotted turtles.

Which amphibians might you find in a New Jersey vernal pool? Some threatened or endangered amphibians are included in the obligate species (meaning they are entirely reliant on vernal pools) including Eastern tiger, blue-spotted, marbled, Jefferson and spotted salamanders, along with wood frogs and Eastern spadefoot toads.

There are also many New Jersey amphibians who will breed in vernal pools but can also use more permanent bodies of water. This group includes the Southern gray treefrogs, Pine Barrens treefrogs, long-tailed salamanders, carpenter frogs, Fowler’s toads, Northern gray treefrogs, Northern spring peepers, bullfrogs, and four-toed salamanders.

We have written in other posts about the dangerous spring move by amphibians from their upland winter hibernation spots to vernal pools. The journey may be short but in NJ it often means crossing roads that separate upland forests from breeding pools. This migration occurs on rainy nights when the temperature is above 45 degrees Fahrenheit. 

In our state, there are volunteers who each spring work at the busiest crossings to slow traffic. In other places, roads are even shut down entirely. (East Brunswick Township has closed Beekman Road on spotted salamander migration nights and the town’s Environmental Commission invites families to come out and see the crossings and the schools teach amphibian ecology.)

Blue-spotted salamander by GRMule, Public Domain, Link


Sunday, April 4, 2021

In Spring Comes Vernal Pools

Spotted salamander   Image: Peter Paplanus/Creative Commons

I wrote earlier about amphibians on the move for mating during warm spring nights. They are headed for vernal pools.

These vernal (spring) pools are also known as intermittent or ephemeral ponds. These pools give eggs and tadpoles the best chances for survival. These are not year-round ponds and by summer they will dry up. That means they don't allow fish to survive ther. Fish are voracious eaters of egges and tadpoles, so that's what make vernal pools ideal places for amphibians.

These pools are created by snowmelt, spring rain and rising groundwater. It is estimated that New Jersey has 3,000 to 5,000 vernal pools. NJ had more snow this winter than last, so that should benefit amphibians.

There are several near me in woods that I often walk and so I will go out some warm spring evening after rain and listen for some frog chorus singers. I might see some amphibians crossing a road. This always makes me think "Why don't they just live in the woods and avoid the dangerous spring commute?"

Luckily, my local pools are in places that will not be developed. But many vernal pools get filled in, level, and built on or near as homes and businesses move in. The amphibians won't know that until the next spring when they make that journey and can't find the pool they expected. The mating still occurs and the eggs will still be laid but the location will be less hospitable to the offspring.

Tuesday, April 14, 2020

Providing Wild Crossings for Endangered Species

Turtle using a tunnel under a roadway

CHANJ is Connecting Habitat Across New Jersey, an effort to make New Jersey's landscape and roadways more permeable for terrestrial wildlife. By identifying key areas and actions needed to achieve habitat connectivity across the state, CHANJ offers statewide mapping and a Guidance Document to help prioritize land protection, inform habitat restoration and management, and guide mitigation of road barrier effects on wildlife and their habitats.

Mackenzie Hall
Mackenzie Hall, ENSP biologist


CHANJ is featured in a new episode of the PBS show, EcoSense for Living.  In this episode, "Wild Crossings," NJ is one of three major habitat connectivity projects, from North Carolina to New Jersey, that are helping wildlife navigate our increasingly developed world.  

In this program, CHANJ comes in at the 14-minute mark but I recommend watching the entire 26-minute episode. The CHANJ portion is 12 minutes and covers salamander migrations, turtle tunnels, timber rattlesnakes, and various connectivity projects of the NJ Division of Fish and Wildlife. You will even meet the Division's bobcat scat-sniffing dog, Fly.



In finding food and finding mates and adapting to climate change, these creatures must overcome all the obstacles humans and nature have put in their way. This project, which once relied solely on volunteers physically moving the smaller amphibians, is using more sustainable methods to help animals find safe passage in our increasingly developed state.

This time of year is especially important for amphibians who are coming out of hibernation and moving to area with water and vernal pools for their short breeding season.

Volunteer transferring a frog across a roadway on a spring night

Spotted salamander entering a tunnel

Despite our well-known population density, we are fortunate that NJ is also a recognized leader in preserving open spaces for recreation, agriculture, and nature. Nearly one-third of the state’s landmass is now in permanent preservation. NJ boasts a higher percentage of publicly-owned forest land than any other state east of the Mississippi (Widmann 2004). Healthy, connected ecosystems are an important part of that.

bobcat
Bobcat in the northern NJ "Bobcat Corridor"

Bobcat using a dry terrestrial pathway under a road

All images via pbs.org video

Monday, March 20, 2017

Spring Brings Vernal Pools to Life


Eastern Tiger Salamander   Photo by Caitlin Smith/USFWS.
Springlike weather has arrived and left NJ a few times already in February and March, but as the true spring season arrived this morning, vernal pools will appear and become more actively occupied.

Vernal pools are confined wetland depressions, either natural or man-made, that hold water for at least two consecutive months out of the year and are devoid of breeding fish populations.

Here in New Jersey, rural portions of the Skylands, Piedmont, and Coastal Plain landscapes are home to the majority of our vernal pools. These unique ecosystems provide habitat to many species of amphibians, insects, reptiles, plants, and other wildlife.

An endangered species in NJ, the Eastern Tiger Salamanders (Ambystoma tigrinum) are part of the wildlife ritual that happens around those intermittent pools/ponds. This is where many amphibian species go to breed.

Habitat loss and water pollution have led to the decline of tiger salamander populations in the southern portion of New Jersey and by the mid-1970s their known historic breeding sites had been reduced to half - 19 sites.

Consequently, the Eastern Tiger Salamander was listed as an endangered species in 1974 and still remains on the list.

Protecting vernal ponds has led the NJDEP to adopt regulations that affords them protection under the State Freshwater Wetlands Protection Act.

The Eastern Tiger Salamander is only one challenged amphibian species in our state. Their breeding needs or habitat are impacted by water pollution, pesticides, roads, introductions of fish, off-road vehicles and development, especially on private land.

Some populations have been saved from local extinction by the species ability to utilize human-made "pools" such as trenches and construction areas as breeding ponds.

Spotted Salamander
Another vernal pool visitor is the Spotted Salamander (Ambystoma maculatum). This a big salamander that is about 15–25 cm (5.9–9.8 in) long. They are stout with wide snouts. The spotted salamander's main color is black, but can sometimes be a blueish-black, dark grey, dark green, or even dark brown. Two uneven rows of yellowish-orange spots run from the top of the head (near the eyes) to the tip of the tail.

The Spotted Salamander breeds in large groups in vernal ponds in early spring, when the first
warm rains occur. It prefers deciduous or mixed woods. Outside of breeding season, it may be found under debris in humid conditions.

Adults can be observed moving into vernal pools sometime after the first spring rain as early
as the beginning of March. They will remain in these breeding ponds for up to a month before moving back to their terrestrial dwellings. Their range is the Northern and Western part of the state outside the Pinelands.

Amphibians of New Jersey

Vernal Pools in NJ


Wednesday, March 15, 2017

Protecting Vernal Ponds

Vernal Pond BarriersThe NJDEP Division of Parks and Forestry has launched a pilot project to install barriers to protect ecologically sensitive intermittent ponds in Wharton State Forest from damage caused by illegal use of off-road vehicles.

Vernal or intermittent ponds and pools are shallow depressions found throughout our state that periodically dry out as the temperature rises, rainfall varies and the ground water table fluctuates.

These areas are ecologically important because they provide breeding habitat for many of the region’s unique amphibian and plant species.

Fish that would otherwise eat the eggs and larvae of many amphibian species cannot populate these ponds due to their fluctuations.


In the Pinelands, for example, species such as the Pine Barrens tree frog are found in few places outside the Pinelands.

The initial phase of the project in the Pinelands targeted four ponds, as part of a broader effort to protect ecologically sensitive areas in the 125,000-acre state forest. Wharton, by far the largest unit of the State Park System, is located in the heart of the globally unique Pinelands National Reserve, and covers parts of Atlantic, Burlington and Camden counties.

Some off-road vehicle enthusiasts run their vehicles through these ponds both during their wet and dry periods. In the process, their tires leave deep tracks in the ponds and destroy plants that fringe them.

Eggs

Organizations involved in the Wharton project were the Pinelands Preservation Alliance, Iron in the Pines, Open Trails NJ, NJPineBarrens.com, the South Jersey Botany Group, the New Jersey Trail Riders Association, South Jersey Geocachers, the Gossamer Hunting Club and the Whitesbog Historic Trust.


Wednesday, March 13, 2013

Spring Rains and Night Journeys

Next Wednesday is the first day of spring, and then April showers, and May flowers. But the spring rains of March are what get the frogs, salamanders, and toads to emerge from their winter burrows to get started on their spring season.

Amphibians like the spotted salamanders, wood frogs, spring peepers, and others are ready to move to breeding pools and lay their eggs. We call those "vernal pools" because they fill with rainwater, snowmelt, and rising groundwater in early spring. These pools will be gone as spring changes to summer advances.

The pools drying out is a good thing for the amphibians because these pools cannot support fish, which are normally predators for the amphibian eggs and young.




The best conditions for the amphibians are warm (40ºF or more) nighttime rains. The journey to the pools occur under the safety of darkness and rain which helps protect from other predators like owls and raccoons.

The Conserve Wildlife Foundation has been partnering with NJ’s Endangered and Nongame Species Program (ENSP) since 2002 to protect early-spring breeding amphibians like the wood frog, spotted salamander, Jefferson salamander, and spring peeper during their annual migration.


Monday, March 4, 2013

Report Local Amphibian Crossings This Spring

Spotted salamander halfway across a road   (conservewildlifenj.org)

Every spring, vernal pool breeding amphibians migrate from upland wintering habitats to their spring breeding pools.  Many of these ancestral migratory paths are bisected by roads, creating a barrier that not only disrupts natural migration and fragments habitat but often proves impenetrable, limiting gene flow and disconnecting populations.

Conserve Wildlife NJ's Amphibian Crossing Project works to protect these migration corridors through coordinated volunteer rescue efforts that move amphibians safely across the road during these annual mass migration events.  Currently, our efforts are focused on select sites in northern New Jersey but we want to expand our database to document these migratory paths across the state.

They do ask that you only report known crossings and do not attempt to locate more by driving around on rainy spring nights. Increased vehicular traffic will increase mortality of amphibians during their annual spring migration.

If you would like to report an amphibian crossing near you, please email them the following information:
  1. Location of the crossing marked clearly on a map
  2. List of species seen crossing or DOR (dead on road)
  3. Date(s) of occurrence and any other pertinent information you may have

Slideshow of volunteer crossing photos

ConserveWildlifeNJ.org/blog/2013/01/11/report-local-amphibian-crossings-during-spring-migration/