Projects 2013 - Toad Pool

In October 2012, I began a project designed to increase the toad population at Blue Jay Barrens.  Toads were once common visitors to the pond during the spring breeding season.  I still hear their mating calls at a distance, but it has been several years since they have been on this property.  Besides missing the toads, I am concerned about the population local Hognose Snakes which feed heavily on toads.  I believe that additional suitable breeding sites will help the toad population to rebound, so I am constructing a series of small temporary pools to serve that purpose.  This is the start of the first pool.

My working tools are a roto-tiller and a scoop shovel.  Tilled soil is scooped up and moved to its new location.  In this pool, excavation stopped just atop the bedrock.

I finished work minutes ahead of the rain and the pool quickly filled.  The local White-tail Deer population was quick to claim this as a preferred watering site.  Soil that was used to form a shallow dam at the low end of the pool suffered severe trampling.  The deer had the area looking much like a confined livestock area. 

The pool was constructed in an area primarily consisting of Tall Fescue, a non-native grass considered to be invasive in areas of native vegetation.  Elimination of the fescue was a primary consideration in choosing this particular site. 

The second consideration was the presence of this seasonal spring located just above the pool site.  My hope was that this spring would produce a strong enough flow to keep the pool full of water.

In January 2013, Jefferson Salamanders returned to the pond for their annual breeding activities.  I had hopes that the toad pool would also support the local salamander population, but knew it was unlikely that any salamanders would appear there the first year.  I was right.  The pool remained empty.

Salamander breeding in the pond was highly successful.  Dozens of egg clusters clung to the submerged tree branches.

Mild temperatures in February brought out several species of aquatic insects that filled the toad pool with eggs.  Since I was going to be making frequent visits to the toad pool through the coming year, I wanted to make sure there would be some interesting things to see.  I thought the insect larvae developing in the pool might support salamander larvae, so I moved a couple of salamander egg clusters from pond to pool.

These five week old eggs are showing well developed salamander larvae.

The stick holding the egg clusters was secured to the pool side so the eggs were suspended in the mid level of the water column.  I was curious to see if the newly constructed pool would be able to satisfy the needs of the developing larvae.

Wood Frogs were actively breeding in the pond, so I moved a few of their egg clusters into the pool. 

Salamander larvae wriggled free of their jelly-like egg masses in late March.

Wood Frog tadpoles, looking more like small leeches than amphibians, fell from their eggs on April 1 and spent several days lying on the pool bottom before becoming free swimming.  I witnessed one salamander larva making a meal of a newly hatched tadpole.

The Wood Frog tadpoles developed quickly and within two weeks were aggressively consuming algae in the pool.

Below normal rainfall in May was cause for concern.  This shot on May 23 shows the pool still full of water.  Had the spring not stopped flowing a week earlier, I would have been confident of the pool’s ability to hold water long enough for the salamanders and frogs to complete their metamorphosis and move away from the water.

A check of the salamander larvae on May 24 showed them to be in good health and vigor.  This individual illustrates the average stage of development and is about two weeks from leaving the water.  A few more rapidly developing larvae had already moved out of the water to hide beneath wet vegetation at the pool’s edge.

Wood Frogs were also well advanced and would be leaving the water soon.  Several had already moved away from the pool.

By May 30 the pool was in danger of disappearing.  Had there been a normal precipitation pattern, the pool would have remained full plenty long enough for the amphibian larvae to leave the water before it left them.

Even though there was still enough water to support life, predator tracks in the mud told me that the young salamanders and frogs could no longer survive in the pool. 

I netted the surviving pool larvae and moved them back to the pond.  The dozen or so remaining salamander larvae would be independent of the water within a few days.  Knowing that salamander larvae survival is often quite low in typical breeding pools, I was happy with the number of pool raised individuals that made it to the land dwelling stage.

The pool as of January 16, 2014.  Vegetation has closed in around the banks and things are looking more hospitable for local aquatic creatures.  So, why have I not mentioned the toads?  Because there were none in 2013.  I see toads occasionally through the summer, but I don’t know where they are breeding.  If I don’t get toad eggs this spring, I may have to corral those I find in the summer and make sure they meet at the right time next year.