Prothonotary Warbler

Prothonotary Warbler

Friday, 4 November 2016

Salamander Snippets

I've recently had several people send me photos of salamanders they've come across, wondering what kind they were. Some are quite easy to tell, but others not so much. What are salamanders doing out so late in the season, you ask? Well it has been warmer than usual, and in reality, salamanders can tolerate quite cold temperatures, even though they are cold-blooded. In fact in the spring, they will emerge from their over-wintering sites and be found mating in woodland pools even while there is still snow on the ground and ice on the water!

One of the most easily identified salamanders in southwestern Ontario is the aptly named Spotted Salamander (Ambystoma maculatum). It is a small type of salamander, but the bright yellow spots are unmistakable.

Another one that is quite easily identified and also small, is the Red-backed Salamander (Plethodon cinereus).


A colour variation of the Red-backed is known as the 'Lead-backed' Salamander, as the back is more grayish than reddish in colour.

Another spotted type of salamander fairly common in southwestern Ontario is the Blue-spotted Salamander (Ambystoma laterale). It is also a small salamander normally ranging between 10-14 cm as an adult. The amount of blue spotting can vary a bit, as the following two images show.


This next image shows both of the latter two species, which I found under the same piece of woody material on the ground.


There are other salamander species that occur, or historically occurred, in southern Ontario but are quite rare. These include species such as Small-mouthed Salamander (Ambystoma texanum) found only in some areas of Pelee Island and Tiger Salamander (Ambystoma tigrinum) which is a much larger salamander that historically occurred in portions of Essex County. I have never seen a Tiger, unfortunately. Others are restricted to the Niagara Gorge such as the Allegheny Mountain Dusky Salamander (Desmognathus ochrophaeus) and Northern Dusky Salamander (Desmognathus fuscus) neither of which I have seen, either. Still others are more often found in eastern Ontario: Four-toed Salamander (Hemidactylium scutatum) and Northern Two-lined Salamander (Eurycea bislineata). Rounding out the line-up of Ontario salamanders are the Mudpuppy (Necturus maculosus), an aquatic species, and Central Newt (Notophthalmus viridescens louisianensis). You can read more about all of these salamanders via the Ontario Nature link provided below.

And that leads me to discussing one of the most challenging and confusing salamanders of southern Ontario: Jefferson's Salamander (Ambystoma jeffersonianum). The Jeff's is largely restricted to south central Ontario, although ongoing research has had it turn up slightly beyond that area. It is a large salamander, with adults reaching 18-20 cm in total length. It is dark bluish black, with a few lighter whitish-bluish flecks, but not as large or as brightly marked as the Blue-spotted Salamander. What makes things especially challenging in identifying these salamanders in the field is a result of the unusual reproductive process and ultimate genetics of these two species. They hybridize, and there is a broad zone of hybridization. One can really only tell what kind one is by doing DNA analysis, which for these salamanders requires snipping a small tip of the tail, running it through a blender of sorts, and then examining the DNA. There are many variations of the genetic make-up of these hybrids, as there are crosses and back-crosses through many generations. It is by far one of the most bizarre and complicated reproductive systems of any organism, which is still puzzling biologists and researchers. For more information you can check out this link.

In the immediate Rondeau area, there are no known pure Jefferson's Salamanders. However there are individuals that have some Jefferson's genes, and are larger than typical Blue-spotted Salamanders. A few years ago there was some sampling of salamanders in the park. There is a tremendous amount of habitat for salamanders with dozens of kilometres of linear slough habitat interspersed with ridges of woodland habitat. Some of the individuals caught were quite large. This one in the next photo is almost 15 cm, certainly long for a Blue-spotted.
It doesn't have the typical well defined and numerous bluish-white markings that a typical Blue-spotted would have, especially on the body. This one, although it has characteristics of Jefferson's, turned out to be predominantly a Blue-spotted hybrid.

Salamanders are most often found under objects on the forest floor when they are not under ground. Even though they are seldom seen, they are a valuable part of the forest ecosystem, both as predators of worms and grubs as well as being food themselves for larger predators.

Salamanders are just one part of the reptiles and amphibian group known as herptiles. There is an ongoing effort to document the reptiles and amphibians of Ontario through the Ontario Reptile and Amphibian Atlas, coordinated by Ontario Nature. For more information on this worthwhile project, and to contribute sightings if you can, please visit this link.





3 comments:

  1. A great overview - especially of the difficult Jefferson complex. You could direct people to submit their observations to the herp atlas - lots of historic squares you be turned!!!

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    Replies
    1. Thanks, Tanya for your comment and suggestion....I will add the link to the herp atlas!

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  2. We are trying to find a way to communicate the unisex u also to general public
    You did a good job

    ReplyDelete