Category Archives: Reptiles

Ecologically Yours

By Art Goldsmith

August 19, 2015

Another fine summer day in August found me in the company of Grégory Bulté and his Ecology Field Course. Grégory is an instructor at Carleton University’s Biology Department, and according to the university’s website, he is:

“…broadly interested in the ecology, evolution and conservation of animals.”

What this does not tell you is that Grégory’s enthusiasm and knowledge about the life around Lake Opinicon and the wetlands bordering the lake, are boundless.

Officially the course is called “Field Ecology & Natural History” and this year was offered to 12 students during the last two weeks of August at QUBS.

Grégory, with his blue t-shirt in the foreground, here supervises the survey of some of the animals that live along the shores of Lake Opinicon, some rarely being seen at all. The purpose of this field study is to learn about the diversity of the lake and surrounding lands.

Grég raises the trap. The mysteries of the lake are revealed

Turtles, fish, frogs and snakes are briefly captured, photographed, identified and then released. Lake Opinicon is home to some less common turtles, like the Northern Map Turtle (Graptemys geographica) and the Eastern Musk Turtle (Sternotherus odoratus). Note the excellent Latin species names, “geographica” and “odoratus”. They are both so descriptive of the animals. Map Turtles are named for the markings on their shells, which are reminiscent of the lines of a topographical map. Musk Turtles are also called Stinkpots, because they emit a stinky liquid from their musk glands when disturbed.

A Northern Map Turtle swims for the camera. (Photo by Grégory Bulté)
A Northern Map Turtle swims for the camera. (Photo by Grégory Bulté)

Below is a photo by your blogger of a very shy Musk Turtle taken at Lake Opinicon a few years ago. It is rare to see one out of the water. They do, on occasion, emerge onto a snag that angles out of the water, like this one, usually in an area that is well hidden. These are small turtles, usually less than 13 centimetres long. Map Turtles are among our larger turtles. Females in Lake Opinicon have measured up to 26.5 cms long and males up to half of that length. They are often seen basking on larger rocks in our rivers and lakes in Eastern Ontario.

Musk Turtle

This photo of Grég tells us about the joy of the field course. It captures the underlying good feelings from learning in the field. The photos that follow were all taken by or provided by Grég.
This photo of Grég tells us about the joy of the field course. It captures the underlying good feelings from learning in the field. The photos that follow were all taken by or provided by Grég.
The lake, the sky and the clouds dwarf the class as they check a trap. Many fish were in this trap. The majority are sunfish, mainly Bluegills and Pumpkinseeds (Lepomis spp.)
The lake, the sky and the clouds dwarf the class as they check a trap.
Many fish were in this trap. The majority are sunfish, mainly Bluegills and Pumpkinseeds (Lepomis spp.)
Many fish were in this trap. The majority are sunfish, mainly Bluegills and Pumpkinseeds (Lepomis spp.)
Every grade-school kid's first ecology lesson... big fish eat little fish, in this case, a fingerling Bass is swallowing a neighbour not that much smaller than the Bass.
Every grade-school kid’s first ecology lesson… big fish eat little fish, in this case, a fingerling Bass is swallowing a neighbour not that much smaller than the Bass.

Blackchin Shiner

Two of the many representatives of the Cyprinidae family (minnows and carp) in Lake Opinicon. Above is the Blackchin Shiner (Notropis heterodon) and below is the Golden Shiner (Notemigonus crysoleucas).  The Blackchin Shiner is native to the Great Lakes‒St. Lawrence basin. It is a small fish, rarely exceeding 6 cms.  The Golden Shiner may grow up to 30 cms., although most are in the size range pictured below.  This popular bait fish is native to much of eastern and central North America and has been accidentally introduced well beyond its native range.

Golden Shiner

Frogs abound in and around the lake.  The first two photos, above, feature a frog that rarely leaves the water, the American Bullfrog (Lithobates catesbeianus). Our largest frog in Ontario, the Bullfrog is very aggressive with other frogs—and anything else that moves!  The third photo, above right, is a Green Frog (Lithobates clamitans). This is also a large, mostly aquatic frog, which is frequently mistaken for the Bullfrog. Note the clearly visible ridges running down the sides of this frog’s back.  These ridges are distinguishing marks of the Green Frog. Below left is a photo of a Leopard Frog (Lithobates pipiens). Leopard Frogs travel far from the water during the summer months and return to overwinter in lakes and ponds. Below top centre is a Wood Frog (Lithobates sylvaticus), distinguished by facial side masks. Scrunched up on the Milkweed leaf, below right, is a Grey Tree Frog (Hyla versicolor), our loud summer frog. Its call is often mistaken for a bird. As the Latin name suggests, the Grey Tree Frog changes colour to match its surroundings for better camouflage. The Green Frog and Leopard Frog photos were taken by Art Goldsmith. The remaining four photos were taken by  Grégory Bulté.

The other group of common, and usually hidden, amphibians is the salamander (above lower row).  The three species above are best seen in early spring when spring melt waters and warm rains form ponds and pools where many salamanders breed in the evening hours. These salamanders spend most of their time dug into the soil or beneath rocks and fallen tree limbs in moist forests where they hunt for invertebrates. The three of Ontario’s 12 species shown here are, from left, Blue-spotted (Ambystoma laterale), Spotted (Ambystoma maculatum), and the lung-less Eastern Red-back (Plethodon cinereus). The latter is a member of the Plethodontidae family.  The species in this family have no lungs, and therefore are restricted to moist, terrestrial habitats where they breed and lay their eggs.  The other two Ontario members of this family are the Two-Lined and the Dusky Salamanders, neither of which have been recorded at QUBS.

For a slight change of focus, we look at a few reptiles.  Above are two photos of a Northern Water Snake (Nerodia sipedon sipedon) that posed for students.  This common reptile is found in and around ponds, lakes and rivers throughout the southeastern portion of Ontario.  Below is a much rarer species, the Eastern or Grey Ratsnake (Pantherophis spiloides), an effective predator of rodents and other small animals. The large tracts of conservation lands protected by QUBS are vital to the Ratsnake’s  survival as the population in the Rideau Lakes is threatened; whereas in southern Ontario, it is endangered.

Grey Ratsnake

Of course, the underpinnings of any functioning ecosystem are its wealth of native plants and fungi, both macroscopic and microscopic. Fungi make up a very large percentage of the Earth’s biomass.  Then there are the invertebrates—the huge diversity of arthropods in Eastern Ontario, and the other invertebrate phyla—all forming the base of food and energy production for all of us vertebrates.  The previous blog post featured the entomology field course and just a sample of the insects to be found in the area around QUBS.  Here are a few more insects , other invertebrates and a small sample of the local plants.

Note that fungi will be the subject of my next post, Richard Aaron’s Fabulous Fall Fungi field course.

Widespread throughout North America and ecologically significant in our lakes, ponds and marshes, the Yellow Pond-lily (Nuphar lutea), pictured above left provides shelter, food and stabilization for many animals, including some of the aquatic invertebrates. To the right of the Pond-lily is a typical dragonfly (Order Odonata) nymph. The next photo is a freshwater crustacean (possibly the Waterlouse, a species of the genus Asellus, Order Isopoda). On the far right in this sequence of four photos, one of our Leech (Hirudinea) species is pictured.  Healthy ponds and lakes are teeming with these and many other invertebrates, zooplankton and phytoplankton, which provide the basic food for all larger species.

A Jagged Ambush Bug female (Phymata americana) munches on a fly, while two male Ambush Bugs attempt to mate with her.  All of this is happening amongst tiny Goldenrod (Solidago spp) flowers.  This is a LOT of biology in one photo!
A Jagged Ambush Bug female (Phymata americana) munches on a fly, while two male Ambush Bugs attempt to mate with her.  All of this is happening amongst tiny Goldenrod (Solidago spp.) flowers. This is a LOT of biology in one photo!

Laetiporus sulphureus

We will explore in great detail the world of the fungi in our next post. I didn’t see this fungus (above) during the fungi course though.  The Laetiporus sulphureus, which has a preference for Red Oak,  has several common names, including Sulphur Shelf and Chicken-of-the-Woods.

Above, these are aquatic Leaf Beetles, Donacia sp.,  mating and another common aquatic invertebrate, a Damselfly nymph (Odonata).

Monarch Butterfly caterpillar

We are not seeing as many of these on Milkweed as we have in the past.  In a walk with two other naturalists recently, we thought it would be approrpiate to change the name of the Common Milkweed to Monarch Flower, to honour this plant which hosts the Monarch Butterfly caterpillar, like the one shown above.

Hay field

Hay fields, as in the stunning photo above, are an excellent habitat to collect a wide diversity of insects and other Arthropods.  Lastly, the Grégory Bulté Ecology Field Course class of 2015.

Ecology Field Course class of 2015

Newly Discovered Population of Eastern Musk Turtle at Round Lake

Posted by Mark A. Conboy and Sarah M. Larocque

The provincially and nationally threatened stinkpot (Sternotherus odoratus) is common at QUBS, making our population an essential one when it comes to conserving and researching this species. Photo: Mark A. Conboy.

The eastern musk turtle (Sternotherus odoratus), otherwise known as the stinkpot, is a provincially and nationally threatened species. Despite being quite rare throughout most of Ontario, research (summarized in a previous post) suggests that in Lake Opinicon stinkpots may be almost as numerous as the more familiar painted turtle (Chrysemys picta). Occasionally a stinkpot is seen in one of the large lakes adjoining Lake Opinicon, but until recently there were no known occurrences of this species in the QUBS Back Lakes. On August 20, 2011 while sampling fish, we found a hitherto undocumented population of stinkpots in Round Lake. We captured five males and four females among three unbaited fyke nets set in the littoral zone of the lake.

Stinkpots normally inhabit water that is less than 2 m deep, so the presence of stinkpots in Round Lake is somewhat surprising because shallow water habitat is relatively limited. Round Lake is the deepest lake at QUBS (mean depth = 12.6 m; maximum depth = 30.1 m). The shallow littoral zone is confined to two narrow bands in the Lake’s north and south ends. According to recently completed bathymetry measurements, only 6.7 % of Round Lake’s total surface area contains water that is 2 m or shallower. When considering depth alone, it seems that Round Lake is not ideal for stinkpots. However, the limited littoral zone that does exist seems like perfect habitat for a number of reasons: (1) Potential prey species abound; Round Lake hosts the most diverse fish community of any QUBS Back Lake yet surveyed (with 13 species). It should be noted that aquatic invertebrates, rather than fish, tend to comprise most of the stinkpot’s diet. Even if fish represent a small fraction of the stinkpot’s diet, the fish diversity is indicative of a generally healthy and productive ecosystem that includes lots of invertebrates. (2) The shallow bays are heavily vegetated and contain plenty of submerged woody debris for shelter and foraging opportunities. (3) The wetland at the south end of the lake contains potential nesting sites, such as muskrat (Ondatra zibethicus) lodges.

This coming summer we plan to look for stinkpots in Garter Lake which connects to Round Lake by a broad marshy channel. We expect to find them there. In addition to the obvious conservation importance of the Round Lake stinkpot population, there is the potential for future research opportunities. For example researchers will be able to compare the diet and heavy metal concentration in stinkpots and their prey between sites invaded by zebra mussels (such as Lake Opinicon) and non-invaded sites (such as Round Lake). Researchers can then determine whether or not zebra mussels are an important pathway for the transfer of mercury in stinkpots. Of course, high loads of heavy metals such as mercury can have all kinds of negative impacts on turtles so studies such as the one described above can be important in developing essential knowledge when planning a conservation strategy for this threatened species.

The threatened (yet potentially plentiful) eastern musk turtle

Posted by Sarah Larocque

Few have seen the eastern musk turtle (Sternotherus odoratus), more commonly known as the stinkpot turtle. This might seem logical because of its current status as a threatened species both provincially and nationally. Perhaps just as likely is the possibility that this turtle goes relatively unnoticed because of its small size and highly aquatic lifestyle.

With a carapace length of up to 137 mm, the stinkpot is one of North America’s smallest turtles, inhabiting shallow water bodies with muddy bottoms. Stinkpots crawl along the bottom and probe in the mud, sand, and vegetation for food of almost any type. Being bimodal breathers (able to exchange gas in both air and water), stinkpots remain submerged for long periods of time. As a result, the stinkpot often has algae growth on its shell, further camouflaging it from human eyes. Instead of basking out of water, stinkpots bask at the water’s surface with their carapace exposed or floating in among aquatic vegetation, and thereby go unnoticed unlike typical basking turtles.

Rarely leaving the water’s edge, stinkpots are hard to detect, let alone quantify their population size. Fortunately, my work involving hoop nets allowed me to come across the stinkpot on numerous occasions. For example, from my spring sampling of 105 net sets in 2010, we captured 111 stinkpots (74 males; 37 females). In comparison, we only captured 101 painted turtles (Chrysemys picta; 67 males; 34 females), a species that appears quite common. Similarly, in fall with 60 net sets, we captured 48 stinkpots (45 males; 3 females) which was nearly twice as many as the 26 painted turtles (21 males; 5 females).

Lake Opinicon is known to have healthy turtle populations; however, it is surprising to find that a threatened turtle like the stinkpot has higher catch rates than the commonly found painted turtle. There have also been reports of large numbers of stinkpots in nearby Lower Beverly Lake. For a threatened species, this is good news. Unfortunately, we only have number of captures and neither the actual population size nor data on whether populations are increasing/decreasing/status quo.

The stinkpots threatened status is in part from attributable to such factors as shoreline development and boat collisions.  Yet perhaps in part its status is due to it being difficult to detect … maybe these small critters are more plentiful than once thought (at least in Lake Opinicon)!