Thursday, 12 July 2018

All the herps of Ontario, finally!

This summer, one of my goals was to finally complete my Ontario herp list.While birds have dominated my life over the past seven years or so, the pendulum is beginning to shift back and I am finding greater satisfaction in a wider range of taxa, while also returning more frequently to my first love - reptiles and amphibians. Between the years of 2007 and 2010 I found myself spending every spare moment in search of reptiles and amphibians and over that time period I managed to catch up with most of Ontario's species, while picking up a few others (Boreal Chorus Frog, Mudpuppy) in the time since. But three species remained, going into this summer - Wood Turtle, Allegheny Mountain Dusky Salamander, and Northern Dusky Salamander. As I detailed in a previous post, I finally encountered my first Ontario Wood Turtles early in June, leaving just the two Desmognathus salamanders.

The genus Desmognathus is quite diverse across eastern North America with around 23 species as currently described. These salamanders are often very closely tied to aquatic environments - most species are limited to streams and seeps in forested, hilly terrain. Two species are found in Ontario, but they are both relatively recent additions to the province's herpetofauna and both have exceedingly tiny ranges in Ontario as currently known.

The story goes something like this: Historic accounts from 1908 and the early 1940s mention dusky salamanders from somewhere along the Niagara River. In 1989, two populations of dusky salamanders were discovered on the Ontario side and initially both populations were assumed to be Northern Dusky Salamanders. In 2004, suspicion arose from Ministry of Natural Resources staff that one of the populations may be a different species - the Allegheny Mountain Dusky Salamander - and genetics confirmed it. Extensive surveys along the Niagara gorge discovered an additional population, which was also identified as Allegheny Mountain Dusky Salamander. Further surveys have been completed throughout the gorge, but no subsequent populations have been identified.

This summer I went on a few scouting trips at various locations along the Niagara River gorge in hopes of finding duskies, or at least, narrowing down my search area. By the beginning of July I felt that I had a pretty good idea of where both species were found so Dan Riley and I planned to meet up to give it a whirl. Like me, Dan had also seen every herp in Ontario other than the two duskies.

The terrain is exceedingly difficult in some of the areas we searched, but with determination in our minds and empty memory cards in our cameras we pressed on. It wasn't going to be an easy search. We took extreme care to avoid tumbling down the side of the gorge.

The herping gods were smiling down on us and I discovered our first dusky of the day, and the only Allegheny Mountain Dusky Salamander we would come across. Much hooting and hollering ensued!

Allegheny Mountain Dusky Salamander (Desmognathus ochrophaeus) - Niagara River gorge, Ontario

Allegheny Mountain Dusky Salamanders are daintier and less robust than Northern Dusky Salamanders, while also exhibiting a tail that is rounded in cross-section (versus the keeled tail of Northern Dusky Salamanders). Allegheny Mountain Dusky Salamanders often have a light stripe down their back, usually with dark chevrons that run parallel to each other down the stripe. Like most dusky salamanders, this species is quite variable - for instance, the individual we found did not show the chevrons down the back.

Allegheny Mountain Dusky Salamander (Desmognathus ochrophaeus) - Niagara River gorge, Ontario

We were ecstatic and could have kept searching, but the day was young and we still wanted to put in a solid search for Northern Dusky Salamanders. Additionally, the total amount of habitat occupied by the Allegheny Mountain Dusky Salamanders here is quite small, and we wanted to reduce any impacts caused by us. We methodically made our way back to where we parked, taking care to disrupt the habitat as little as possible.

I had not quite pinpointed the location that the Northern Dusky Salamanders can be found, just a general area, but we got to work. We noticed this young Northern Watersnake while exploring the Niagara River gorge - the first one I have ever seen here. It was in the deep forest near a small stream trickling down the escarpment, which is not where I would have expected to see one.

Northern Watersnake - Niagara River gorge, Ontario

I don't want to give too many details for fear of giving out the exact location, but again luck was on our side and Dan discovered a Northern Dusky Salamander after we had been searching for a good few hours. Again, much mayhem ensued along with quite a few high fives. We couldn't believe it that we had now both seen every herp in Ontario!

Northern Dusky Salamander (Desmognathus fuscus) - Niagara River gorge, Ontario

As is typical for the species, this Northern Dusky Salamanders is a heftier animal, compared to the Allegheny Mountain Dusky Salamander from earlier in this post. It is also much drabber in colouration and shows that distinctive keeled tail.

Northern Dusky Salamander (Desmognathus fuscus) - Niagara River gorge, Ontario

Once we were in the right habitat the salamanders were not hard to find and we quickly found four more. Astonishingly, three of these were females with nests of eggs!

Northern Dusky Salamander (Desmognathus fuscus) with eggs - Niagara River gorge, Ontario

It is not uncommon for Northern Dusky Salamander females to guard their eggs, much like many other species of lungless salamanders. We took care not to disturb these salamanders, quickly taking a few photos and then letting them be.

Northern Dusky Salamander (Desmognathus fuscus) with eggs - Niagara River gorge, Ontario

Northern Dusky Salamander (Desmognathus fuscus) with eggs - Niagara River gorge, Ontario

These eggs are relatively young but the developing larvae are visible in the photo below (this nest was the most advanced nest of the three).After several weeks the eggs will hatch into aquatic larvae which inhabit eddies and quieter sections of the stream. The aquatic larvae take anywhere from a few weeks to eight months to transfer into the adult form.

Northern Dusky Salamander (Desmognathus fuscus) eggs - Niagara River gorge, Ontario

Northern Dusky Salamander (Desmognathus fuscus) with eggs - Niagara River gorge, Ontario

Dan and I were thrilled with our successful day, and to finally finish off our herp lists in Ontario, as it was a long time coming. While there may be no more new species for us in the province I still have many goals with my herping endeavors. Below are a few of the things that I would like to still see in the province:

-Boreal Chorus Frogs: I have heard them several times and seen one in Northern Ontario but it is not a species I have seen well and is the only herp I have not photographed
-the southwestern Ontario population of Gray Ratsnake
-finding more Small-mouthed Salamanders on Pelee Island that appear to be "pure" individuals
-exploring some rivers in northern Ontario that I suspect have Wood Turtles
-finding a Massassauga in Niagara Region, where they are still hanging on
-observing those really cool Wood Frogs in the far northern reaches of the province that exhibit a light stripe down their back and more extensive patterning
-locating more populations of Pickerel Frogs

No comments:

Post a Comment