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

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...

Stream Salamander Survey, Van Winkle Rd., 9/13/11

Northern Dusky Salamander

photo from www.uga.edu

Northern Two-lined Salamander

photo from http://www.fish.state.pa.us/

Green Frog juvenile photo by Dave Rosgen

On Tuesday afternoon, 9/13/11, I surveyed the brooks that run between E. Shore Rd. and Van Winkle Rd. in Morris for salamanders and other amphibians. In most years these streams can be classified as seasonal since they largely dry-up during the months of July and August. Not this year! Even though dry conditions for awhile in July and early August reduced water flows in these streams to a trickle, they still held enough water to support amphibians and aquatic macroinvertebrates. The double whammy of Tropical Storms Irene and Lee in the past 2 weeks sent torrents of water down these streams. The embankments were scoured-out in several places and at least 25 trees were undermined to the point of falling across or along the stream channels. On 9/13 these streams continued to hold and flow a decent amount of water. Walking along them proved to be difficult, or even impossible, in a few places due to the downed trees and shrubs. Despite this, I was able to survey quite a good amount of habitat between the 2 roads. The smaller feeder streams didn't host any amphibians except Green Frogs, but the main stream really produced. I found 21 Northern Dusky Salamanders, 1 Northern Two-lined Salamander, 31 Green Frogs, 2 Wood Frogs, 2 Gray Treefrogs, and 1 Northern Spring Peeper in the 1/4 mile between the 2 roads. I only found Green Frogs in the short section of this stream between Van Winkle Rd. and Bantam Lake. Of the Dusky Salamanders, 19 were adults and 2 were juveniles. I didn't see any larvae. The N. Two-lined Salamander was an adult. All of the frogs were juveniles. It is also worthwhile to note that the water was crystal clear and quite cool. Sediment loads appeared to be less than had been present in previous visits this year and in the past 5 years. That boads well for amphibians.