Monday, March 10, 2014

Salamander Breeding

In my opinion, there has not been a single night during the past three months that has had conditions suitable for salamanders to migrate overland to their breeding ponds.  Fortunately, the salamanders don’t have to wait for my approval to begin their courtship activities.  Mature salamanders are now abundant in the pond and it looks to be a record year for egg laying.

I’m still trying strategies for providing safe locations for attachment of salamander egg clusters.  My latest idea is a floating branch that can be moved to deeper water if drought causes a dramatic decline in pond water depth.  The jug acts as a float to keep the stump end of the branch from catching on the pond bottom.

The branch was favorably received by the salamanders.  The smaller stems are heavily garnished with jelly-like bags of salamander eggs.  Some people question my manipulation of this aquatic habitat, but some type of management becomes necessary when the pond and the associated amphibian population are not natural to this site.  Prior to construction of the pond approximately 60 years ago the site was dry and provided no aquatic environment in which amphibians could live or breed.  So, all of the frogs and salamanders currently breeding in the pond had to have come from somewhere else.

Up until 30 years ago, the pond held water year round and supported a population of stocked fish.  It was not until the fish could no longer survive that the pond became a suitable amphibian breeding site.  The few egg clusters I saw during my first years at Blue Jay Barrens may have been the first successful breeding attempt in the pond.  This single long branch contains more salamander egg clusters than could be found in the entire pond a mere 20 years ago.

It makes sense to assume that a point has been reached where new mature adult salamanders join the breeding population each year.  The adults are apparently finding a suitable subterranean environment in which to spend their time away from the pond.  A place that once had nothing to offer to salamanders is on its way to becoming a salamander oasis.

In several places the egg clusters were placed closely together to form a large mass.  These were attached to short grass left in the center of the breeding pool.  They should be at a depth that protects them from fluctuating water levels.

Across the pond bottom were areas of concentrated egg masses, individual clusters and even some instances of single eggs.

I was thinking the eggs were all newly placed until I noticed some jelly envelopes containing nearly developed larvae.  There had obviously been some minor breeding activity several weeks earlier than the latest explosive event.  Although I kept watch on the pond in an attempt witness the arrival of the salamanders, the 90 percent ice cover during the last two months has made observations difficult.  My manager self will have to explain to my staff self the need for vigilance in these types of pursuits.

By the time the newest eggs hatch, the earlier batch should be grown enough to find the hatchlings to be a tasty mouthful. 

Adult salamanders glided like shadows across the pond bottom.  It was evident by the activity that breeding was still ongoing.  Two individuals are shown here; one just below center and one top center.

Most of the salamanders were well outside my net range, but I was able to scoop a few near the shore.  I don’t know of anywhere nearby that could have been the original source for this Jefferson Salamander.  I know that a few individuals in each population are inclined to wander, but it would have been quite a journey for the Jefferson’s ancestors to travel to this pond.

I’m not sure what label should be properly attached to this guy.  Prior to the publication of the new Amphibians of Ohio book, I would have called it a Smallmouth Salamander.  The book puts the Smallmouth’s range at least 60 miles from Blue Jay Barrens.  Now I’m led to believe that this is a Streamside Salamander, a species that does breed in the local streams.  The Streamside is not a pond breeder.  Instead, it lays its eggs beneath flat rocks in the creek.  Apparently, in a pond situation, it can lay its eggs beneath logs, leaves or other vegetation and that may be what it’s up to here.  I think that next year I’ll put some boards and flat rocks in the pond and see if any Streamside eggs show up beneath them.  That should provide some answers.

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