Shannon's Salamanders: Increasing our amphibian survey with the help of a local graduate student

We started the 2018 season by chopping wood, and lots of it. Slab wood left over from the milling process has been piling up on White Memorial’s property, and we knew exactly who could use it- Amphibians. This summer started out with hauling this wood out into the woods to increase the number of amphibian cover board grids. These grids get surveyed every year to get an idea of amphibian diversity and abundance at White Memorial. This year, it got taken to the next level.

Shannon shown here excitedly showing off a Four-Toed
Salamander she found at one of the grids

Shannon Smith, Litchfield native and Trinity College student, completed her Master’s thesis on White Memorial’s salamanders. Specifically, how Red-Backed salamanders are affected by invasive non-native earthworms. To help Shannon get data for this project, we doubled the amount of cover board grids present on the property, and aided her in field work whenever we could.

Shannon is shown here surrounded by her research
materials. 4 1-Gallons jugs of water mixed with mustard
were brought to each plot, no matter how remote

Her methods required sampling of salamanders, earthworms, leaf litter, and soil invertebrates for each of the 40 grids. Each grid took about 2 hours, a lot of grit, a good sense of direction, and tons of Tecnu to complete.  

Some of the research materials on top of a cover board.
Each grid had 25 of these cover boards that needed
to individually be flipped and analyzed for salamanders

Her research questions evolved as time went on, as is normal for research in this field; so little is known about the earthworm invasion and its implications. Because about half of the cover board grids she sampled had been present for years prior to her project, and the other half had just been dealt out only a few months prior, she had to account for the dispersal rate of these animals to the new grids.

She found that the strongest influences on salamander abundance were leaf litter quality, soil temperature, and invertebrate community diversity.

Red-Backed Salamander found in Shannon's
research

Non-native earthworms decrease the quality of the leaf litter, and also decrease diversity of soil invertebrates. This means that earthworms are indirectly having a negative impact on CT’s Red-backed salamanders.

Red-Backed Salamanders are Connecticut's most abundant amphibian. By consuming large numbers of soil invertebrates which are otherwise unavailable as food for larger animals, Red-Backed Salamanders play a key role in moving nutrients up the food web. They are eaten mainly by songbirds, but also mammals of many sizes and also larger amphibians. 
This study is showing that earthworms may be negatively affecting these amphibian's ability to play that key role in the food web. Earthworms are altering the soil environment for these important amphibians by decreasing the amount/diversity of soil invertebrates and influencing the leaf litter layers.  This could have serious ecological effects reaching far up the food web.  More research is needed to understand the role that non-native earthworms play in our soil, and how they are affecting other soil invertebrates. 

You can help limit the earthworm invasion by not dumping unused "night crawlers" or other worms in the forest but rather the trash bin.  Recognize that earthworms are having huge impacts on forest health, and try not to spread them around. 

Four-Toed Salamander, a species much less
common than the Red-Backed

Amphibian Cover Board Monitoring Detects Possible Case of Scoliosis in Red-backed Salamander

A possible case of scoliosis was observed in this red-backed salamander (Plethodon cinereus).
The dimensions of the cells on our data sheet are 10 mm x 17 mm.
The defomity I am pointing out is the curviture along the body length.
There is a Eastern hemlock (Tsuga canadensis) needle stuck to the tail.  

We monitored Amphibian Cover Boards and observed a total of 56 red-backed salamanders (Plethodon cinereus) and 9 red eft stage of red-spotted newts (Notophthalmus viridescens).  This project consists of a total of 19 cover board grids located in suitable habitat for monitoring the blue-spotted x Jefferson Salamander hybrid (Ambystoma laterale x jeffersonianum) population on the property.  We observed one red-back salamander that displayed a deformity that could be a possible case of scoliosis.  I credit Brian Kleinman, Herpitologist at Riverside Reptiles, for suggesting this as a possible case of the deformity.  Although this is the first observation that we have recorded for the property, we'll continue monitoring our amphibian population to detect the frequency of this deformity.  The individual we observed displayed a full range of motion and speed so at first glance this deformity did not appear to affect the animal negatively.  The animal was living is a mesic forest dominated by Eastern hemlock (Tsuga canadensis), which was surrounded by shrubby and herbaceous wetlands.

Amphibian Cover Board Experiment Monthly Check -- September 2012

Amphibian cover boards were checked Friday, September 7^th and revealed some great finds. First off, there were a total of twenty-nine Red-backed Salamanders and seven Red Efts found underneath the cover boards. Also uncovered was one Spotted Salamander. Spotted Salamanders do not usually reside under the cover boards but are often found near vernal pools and in crevices of rock walls and tunnels. Most importantly, there were two Blue-spotted x Jefferson Salamanders at two different sites. Based on the small size of these two salamanders, we assumed that they had just metamorphosed into the terrestrial adult stage, which takes place by September.  


Blue-spotted x Jefferson hybrid Salamander

The conditions for checking cover boards Friday were ideal due to the heavy rain at the beginning of the week. The warm, humid weather, also contributed in creating moist soil conditions that are favorable for amphibians. Since fall is around the corner we can expect drier, cooler conditions, but we can still anticipate to see some salamanders under the cover boards. During the winter months when temperatures reach close to freezing, (32-41° F) salamanders will go into hibernation on land and burrow under logs, rocks, and loose soil in order to maintain a stable body temperature. During this time the salamander’s metabolism is greatly reduced, thus decreasing the amount of calories burned to successfully make it through the winter. By early spring, rain and warmer temperatures wake the salamanders just in time for the breeding season.



Spotted Salamander

Juvenile Red-backed Salamander



Amphibian Cover Board Monthly Check - July 2012

Red-backed Salamander with six newly hatched salamanders.
Photo by Erin Caruso 

Today’s monthly check of the amphibian cover board experiment grid revealed forty-six individual salamanders. The amphibians that Nicole Morin and I came across were mostly Red-backed Salamanders, although we did see five Red Eft, one Northern Two-lined Salamander, and one Wood Frog. Twenty-two Red-backed Salamanders were under the softwood cover boards and eighteen were discovered under the hardwood. Two of Red-backed Salamanders under the softwood were found coiled around their young. This was an exciting event to come across because this strengthens our theory that the cover boards provide a favorable habitat for salamander reproduction. In addition, their population growth signifies a healthy forest environment. When it comes to reproduction, Red-backed Salamanders are unique because they lay their eggs on land, while most other amphibians and salamanders such as the Blue-spotted Salamander attach their eggs to underwater twigs or vegetation. These underwater eggs hatch and go through an aquatic larva stage. In contrast, the Red-backed Salamander young go through the larva stage while still in the egg, and when they hatch, look like miniature adults. Since the month of August is usually when most salamanders emerge from their eggs, it will be interesting to return to the cover board experiment grid at the end of next month and see if we can find a higher abundance of baby salamanders.

Lead phase Red-backed Salamander with egg cluster.
Photo by Erin Caruso

The Effects of Dry Weather & Salamanders

Red-backed Salamander

Yesterday’s amphibian cover board check yielded a relatively small encounter rate of salamanders. A total of 23 Red-backed Salamanders were seen at fifteen cover board grids. Only one Red Eft was spotted as well as one White-footed Mouse. The low encounter rate could be due to the recent dry weather we have been having across the state. Although I checked the cover boards after yesterday morning’s heavy rain shower, the forest floor still seemed to be dry and what was once moving streams and filled vernal pools were now reduced to only mud. Moisture is necessary for the survival of many salamanders, especially the Red-backed Salamander which is born without lungs forcing it to breathe through its skin. Therefore the exchange of oxygen and waste gases through the skin demands a moist environment. The drought in Texas can be used as an example of how a long period of dry weather can diminish salamander populations. The already endangered Texas Blind Salamander population has dwindled due to the drought and was captured by the U.S. Fish & Wildlife Service to bring to a hatchery for a chance at preservation. As the summer progresses we hope to find a greater amount and diversity of amphibians underneath our cover boards. Whether or not this can be achieved can depend greatly on the amount of precipitation we receive.

A dry stream near Duck Pond.

Amphibian Cover Boards Yield Blue-spotted x Jefferson Salamanders

Blue-spotted x Jefferson hybrid Salamanders were encountered today while checking amphibian cover board grids. A total of fifteen grids yielded 2 Blue-spotted x Jefferson hybrids Salamanders, 11 Red-backed Salamanders, and 12 Red-spotted Newts (eft stage). The Blue-spotted hybrid Salamander is always an exciting amphibian to come across due to its endangered species status in Connecticut. The cover boards are used as a method to monitor their population at White Memorial.

Blue-spotted x Jefferson hybrid Salamander

Seven newly constructed cover board grids were checked today for the first time. Only three of the grids had salamanders underneath them, indicating that the grids without any salamanders were either not placed in appropriate amphibian habitat or the boards have not been there long enough to attract any salamanders. The recent hot weather also seemed to dry out the leaf litter under many cover boards, which is not favorable conditions for the moisture-loving salamanders. As the summer progresses I will be interested to see what other kinds of amphibians we find under cover boards and if the Blue-spotted x Jefferson hybrid Salamanders will become more prevalent.  

Red-spotted Newt

Red-backed Salamander

Amphibian Cover Board Monthly Check - June 2012

On Tuesday, June 19^th James Fischer and I went out to the Solnit Parcel to do the monthly check of the experimental amphibian cover board grid. We were able to encounter 93 salamanders; 45 under the softwood boards and 48 under the hardwood boards. The majority were Red-back salamanders, although we did see 2 Four-toed salamanders, 17 Red Eft, and one wood frog. We noticed that most of the salamanders that we found were located in areas of dense fern stands. These ferns provide lush habitat for amphibians by keeping moisture and leaf mold intact.



Four-toed Salamander (Hemidactylium scutatum)

We were lucky enough to find a female lead phase Red-backed salamander guarding her eggs underneath a hardwood board. This is not a common spectacle to come across because Red-backed salamanders only mate every other year. After laying her eggs the female will coil her body around them and protect the eggs for two months until they hatch. The eggs are laid in a cluster, so they are somewhat difficult to count, but I estimated there to be 30 eggs in the cluster. Once the eggs hatch the baby salamanders look like miniature adults and after two years will reach reproductive maturity.



Red-backed salamander (Plethodon cinereus) with eggs.

Amphibian Cover Board Results

Today the amphibian cover boards were checked for a second time this summer. Interestingly enough the total number of salamanders that were found, 28, was the exact same number as last time the cover boards were checked in the middle of May. Also, like last time, I was only able to encounter the Red-backed Salamander (Plethodon cinereus) and the Red-spotted Newt (Notophthalmus viridescens). However the major difference between this survey and May’s survey was that this time the salamanders discovered were less dispersed over all the grids. The Duck Pond and Pine Island grids, which are very close together in location, held the majority of salamanders, 10 and 11, while the Mott-Van Winkle Area had 4 salamanders, and the Interpretive Trail, Icehouse Marsh, and Butternut Brook, each had 1 salamander, respectively. In May, the total number of salamanders was spread out more evenly among almost all the grids, although Pine Island did have the majority of salamanders. The Duck Pond and Pine Island grids are located in a conifer dominated forest, next to a pond or vernal pool. Therefore we can hypothesize that the Red-backed Salamander and Red-spotted Newt prefer this type of habitat, which stays moist and cool from the conifers and harbors many invertebrates due to its proximity to water. 

Lead phase Red-backed Salamander

Red-backed Salamander

Typical Cover Board Grid

Red-spotted Newt (eft stage)

Over the past week we have added seven more amphibian cover board grids around White Memorial, focusing on the Catlin Woods area. We have also flagged three additional sites around the property to place more cover boards. These new grids will be left undisturbed for several weeks in order for salamanders to become established there. Hopefully by the end of the summer we will be able to survey all of the grids, both new and old, and really discover various amphibians’ ranges and will come across a population of Blue-spotted x Jefferson hybrid Salamanders. 

Increasing Amphibian Cover Boards at White Memorial

Over the past five days two more amphibian cover board grids have been added to White Memorial’s property. This will make a total of ten cover board grids located around the property. We plan on adding even more grids over the next couple of weeks to locations around the Catlin Woods and the Cranberry Swamp area. By adding more cover boards we can expect our amphibian encounter rate to increase, as well as our chances of encountering Connecticut’s endangered Blue-spotted x Jefferson hybrid Salamander.



Red Eft life stage of a Red-spotted Newt in Catlin Woods

We experimented with one of the newly assembled cover board sites by removing leaf litter underneath every other cover board, exposing the bare, damp soil. When a piece of wood or any heavy object is left on the forest ground, the leaf litter that it shields eventually breaks up and decomposes, therefore becoming part of the soil. We wondered whether by accelerating this process, so that only soil meets the cover board, the salamanders would be more likely detected because there isn't any leaf debris that can cover them. This observational experiment will help us see if there is a noticeable pattern and tell us if we should develop an experiment with more replicates. We will check the plot every couple of weeks noting if salamanders were more often discovered under removed leaf debris cover boards. We need to be especially thorough when checking the uncleared cover boards because salamanders are more difficult to spot when there are layers of leaves that they can hide in. By not counting all salamanders present, this may result in a false correlation in our experiment.

James Fischer marking the cleared leaf debris cover boards.

Amphibian Cover-board Monthly Check -- November 2011

Redback Salamander (Plethodon cinereus)

Winter is here or at least the amphibian's behavior suggests it has arrived.  We encountered only 7 Redback Salamanders during Friday's visit to the grid.  Faye Curran and Abby Conroy helped with today's check and we were all thrilled to see the few salamanders that we observed.  The temperature was about 35 degrees Fahrenheit with a clear sky and only a slight breeze.  All of the salamanders were observed under cover-board stations under deciduous tree cover.  I think this is due in large part to the lack of leaves in the trees to shade the ground which exposes the ground to more solar radiation.  The cover-boards under the conifer canopy were very shaded and would have been cooler.  Thanks to Faye and Abby for a solid day's work, especially since we observed so few salamanders and it was rather chilly.  This will likely be our last check for the 2011 calendar year.  Check back to see when we return to the grid.

Late Season Reptile & Amphibian Activity

Northern Brown Snake photo from

www.piplon.org

Eastern Garter Snake photo by Dave Rosgen

Painted Turtle photo by Darlene Knox

Wood Frog photo by Ashley Hayes

Northern Spring Peeper photo by Ashley Hayes

Green Frog photo by Ashley Hayes

By the middle of November most reptiles and amphibians are starting to hibernate or brumate (a less deep sleep than hibernation). However, since part of this is temperature driven, and temperatures have fluctuated widely for the past 3 weeks, some of these animals have remained at least partially active. The majority of these have been Northern Spring Peepers, which are commonly heard peeping every fall well into November. Whether they are confused about the season or their peeping failed to get them a mate last spring is unknown. A Wood Frog, which is a species that hibernates under logs and other forest floor debris and emerges real early in the spring, was seen at Little Pond on the 13th. Green Frogs were seen on several occasions, including several hopping across White Hall Rd. by Pike Marsh on some of the recent mild, rainy evenings, and a few at Mallard Marsh. Last Tuesday, 11/15, Nicole Morin and I saw a Redback Salamander under a log along the Interpretive Trail and a Painted Turtle sunning itself at Ongley Pond. Later in the week, Jim Kandefer saw an Eastern Garter Snake along the Little Pond Boardwalk. The nearby Little Pond Trail produced our best herp find this month in the form of a baby Northern Brown Snake on the 12th. With the weather forecasted to continue to fluctuate between mild and chilly for the next 2 weeks, we may continue to see these animals for awhile.

Notable Wildlife Sightings at White Memorial, 10/24 & 25/2011

Rusty Blackbird photo from

www.borealbirds.org

Four-toed Salamander photo by Dave Rosgen

Eastern Red Bat photo from

www.lakecountyspecies.org

This past Monday and Tuesday, 10/24 and 25/2011, produced a fair number of notable wildlife sightings on White Memorial property. Tops among these were an Eastern Red Bat which I saw flying around Ongley Field between 6:00 and 6:10 p.m. on Monday. It then headed off to the south. This is a rather late date for this Connecticut species of special concern. The nearby Activity Field produced a Field Sparrow and a Purple Finch for notable birds earlier this day. On Tuesday, Nicole Morin and I visited the salamander cover boards along the Windmill Hill and Butternut Brook Trails for their final inspection of the year. One of the Windmill Hill boards yielded a Four-toed Salamander, which I think is only the second one of this species found under a board in this plot since we established it about 7 years ago. The rest of the boards in this plot produced a total of 11 Red-backed Salamanders on this visit. About half of these boards were awash in floodwaters a month ago. Interestingly, the cover boards at Butternut Brook, which were completely inundated last month, produced absolutely no salamanders on this visit. However, they did harbour at least 40 earthworms. The Windmill Hill boards had only about 15 earthworms under them. Farther along the Butternut Brook Trail we encountered a nice flock of 18 Rusty Blackbirds feeding under the shrubs in the swampy area. They are a regular, but uncommon fall migrant through this area.

Amphibian Coverboard Experiment Monthly Check -- October 2011

Spotted Salamander (Ambystoma maculatum) discovered under a
cover-board just as it emerged from it's mole-like tunnel.
Photo by James Fischer  

I observed an amphibian at 57.6% of the cover-board (CB) stations yesterday.  This is the highest proportion of stations that detected an amphibian ever observed during our monthly visits to this site over the past 2.5 years!  This is exciting news but I want to tell you about another interesting observation that I made.

A yellow-hued Spring Peeper (Pseudacris crucifer) camouflaged
among newly fallen autumn leaves.
Photo by James Fischer  

The CB grid spans across two stands of trees, one stand is dominated by deciduous trees while the other are evergreen trees.  The CB stations under the deciduous trees detected more amphibians than the stations under the evergreen canopy.  This puzzled me while I was traversing the grid from station to station.  I walk the grid a systematic fashion so that it takes less time.  I walk the grid along the lines within the grid from the evergreen stand to the deciduous stand and back again.  But that question kept bugging me. Why were more amphibians observed under the CB's in the deciduous stand rather than the conifer stand?  I think I may know but I need to tell you about another pattern that I observed whilst walking the line.  This was a new pattern for me this season.  I was wearing my sunglasses while I was in the deciduous stand and not in the evergreen stand.  Okay, if I lost you, please keep reading because there is a reason why this is important.

Just as I was beginning to get frustrated with having to pull out my sunglasses from my pocket each time I entered into the deciduous stand, the light hit my eyes and my skin began to feel warm!  Yes, it was noteworthy moment but not the kind you may be thinking of.  I began to think that the amount of sunlight penetrating the forest floor could have been one factor causing this pattern.  It is now autumn in southern New England and many of the leaves have already fallen from the deciduous trees allowing more of the sunlight to reach the forest floor.  The CB's under the deciduous trees should be warmer than their evergreen counterparts, which explains why so many amphibians were observed under these boards.  But lets not rush to this conclusion too quickly!  There could be several other explanations.  I'll offer another possible process just to demonstrate how complex a walk in the woods can sometimes be to biologists and ecologists.

Northern Two-lined Salamander  (Eurycea bislineata) found
under a cover-board near a spring seep.
Photo by James Fischer

Another explanation could be that the leaf litter on the forest floor could also be warmer and more importantly dryer under the deciduous trees while the conifer stand could be cooler and moister.  The amphibians in the deciduous stands would seek out shelter that offers a moister environment.  The amphibians inhabiting the evergreen stand would not have to seek out these micro-habitats.  Moisture is very important to a group of organisms that breathe through their skin.  Moist skin allows for more oxygen to transpire than drier skin.  Amphibians breathe through their skin as an adaptation which has allowed them to lower their metabolism as they evolved which means they require less energy to live.

Who knew flipping cover-boards and a walk in the woods could be so complex...

Salamander Cover Boards

Red-backed Salamander photographed by

Dave Rosgen at WMF's Duck Pond Trail

On Tuesday, 8/23/11, I checked all 174 salamander cover boards at White Memorial's Ongley Pond, Lake, Windmill Hill, Butternut Brook, Interpretive, Duck Pond, and Pine Island Trails, Mott-Van Winkle Area, and the east slope of Windmill Hill. The results were rather disappointing: 50 Red-backed Salamanders, 7 Red Eft-stage Red-spotted Newts, and 2 Northern Spring Peepers. This is despite wet conditions which would seem to favor amphibians. However, I did find huge numbers of earthworms; many of them being of nightcrawler size. Some concern has been expressed by herpetologists about the growing numbers of earthworms (most of which are non-native species) and their possibly ill effects on salamanders. I found at least 500 earthworms under our salamander boards. Five days after this survey, Tropical Storm Irene hit, dumping 8 inches of rain on this part of Litchfield, and flooding most of our salamander boards. Yesterday I found 21 of the 25 boards at the Interpretive Trail floating in the Pike Marsh's flooded backwater. Two boards were missing, and the 2 remaining boards on land harbored 4 Red-backed Salamanders. Of the 20 boards at Mott-Van Winkle, 6 were missing. The remaining 14 boards harbored 3 Red-backs. I'm heading out now to check on the fate of the rest of the cover boards.