by Fred Schueler
Bishops Mills Natural History Centre
RR#2 Bishops Mills, Ontario, Canada K0G 1T0
(613)258-3107 <> http://pinicola.ca/
Report of the talk “Salamanders: Unseen, Unheard, but NOT Unimportant” which was to have been given by Mike Oldham to the Mississippi Valley Field Naturalists (MVFN), 26 January 2012; the 4th lecture in MVFN’s 2011-2012 natural history lecture series: Trends in Flora and Fauna. The report was written by local naturalist Fred Schueler, who was to write this report and thank the speaker, but who also delivered the talk when Mike was prevented by weather from reaching Almonte, after Cathy Keddy reconstructed Mike’s presentation from e-mailed files.
Blue-spotted Salamander Ambystoma laterale (upper photo courtesy Cathy Keddy) is the most frequently encountered species in our area, often wandering into basements or garages, or turned up under wood; the red colour of the terrrestrial stage of the red-spotted newt serves as a warning to predators that the eft is poisonous. Efts such as this one photographed during MVFN’s 2010 bioblitz near Almonte are the only salamanders you’ll see wandering aaround in daylight (lower photo courtesy Karen Thomson)
On 19 Jan 2012 3:26 PM, Oldham, Michael (MNR) wrote:
> I ended up turning around and heading home, so won’t be at this evening’s MVFN meeting this evening. So sorry… It is still snowing very heavily here with lots of accumulation… I just got home and driving back from where I called, between Norwood and Havelock, was even worse than the drive there. Blowing snow, freezing rain, poor visibility, slow snow plows with impatient drivers and truckers trying to pass, slippery roads, snow squall warning in effect, cars in the ditch, and the MNR minivan I was driving is not very good in slippery conditions. I was averaging 40-50 km/hr, often slower in long stretches behind snow plows or sanding trucks, half the speed under normal conditions, so my estimated 3 hr drive would have been 6 hrs, unless conditions improved. I hope the snow squalls abate before they reach your area and affect people travelling to and from Almonte.
I was setting out to drive the Dwyer Hill Road to Almonte when the wife banged on the van window to announce she’d just read Mike’s e-mail, but I was soon setting out again with the plan that I would give Mike’s talk from his e-mailed presentation. All the way up the Dywer Hill Road there was no snow at all, though things were blizzard-like soon after I reached Almonte.
I began the lecture by introducing Mike Oldham, herpetologist and botanist at the Natural Heritage Information Centre (NHIC, Ontario Ministry of Natural Resources) in Peterborough, co-founder, in 1984, of Ontario’s Herpetofaunal Summary, the first modern atlas of “reptiles” and Amphibians, and the person you turn to when you need a copy of any paper relevant to Ontario natural history (and often he’s sent it to you before you ask). I illustrated his scope as a field naturalist from the top of my e-mail SENT box – correspondence about introduced Xerolenta snails and Dyssodia Dogweeds along Ottawa highways, freshwater mussels he’d collected all across southern Ontario, a new book about European Sedges, and the status of invasive Cattails in Ontario…
So Mike is known for his interest in spectacular but inconspicuous creatures, and Salamanders are leading members of this group. This report is compounded of his notes, and my local knowledge of Salamanders in Eastern Ontario.
Salamanders retain the long-tailed, four-limbed shape of primitive land-dwelling Vertebrates, overlaid by a wide range of specialized adaptations. They diverged from the tailless Frogs some time before the earliest known Salamander fossils, from the Middle Jurassic, 164 million years ago. There are now about 550 species of Salamanders in the world. Among provinces, Ontario has the greatest number of species, probably because it is closest to the southern Appalachian region, which is the world centre of Salamander diversity. Our Salamanders range from 35 mm to almost half a metre in length, and show remarkable variation in life histories and habits. Some spend their entire lives in the water, others live on the land but breed aquatically, and some have an entirely terrestrial existence. Salamanders may breathe via gills, lungs, and skin, or can be lungless and breathe only through their skin. Moisture is thus a very important factor regulating their distribution, and they tend to be active on the surface mostly on rainy nights, when potential observers tend to seek shelter.
Salamanders are elusive, and in addition to being rarely seen at the best of times, and on the formerly ploughed and trampled lands of eastern Ontario, they’re often much rarer than they were before settlement, though because of their effectiveness as predators they are often regarded as “keystone predators” in intact forest ecosystems of eastern North America.
Thirteen species of salamanders are known from Ontario, including six that are legally listed as “at risk” either federally or provincially: none of these, and all of the others, occur in eastern Ontario. The “at risk” species fall into 2 groups, stream salamanders of the Niagara Peninsula, and hybridizing Ambystoma Mole Salamanders of southwestern Ontario.
There is only a single confirmed record of the Eastern Tiger Salamander (Ambystoma tigrinum), from Point Pelee in 1915. The Jefferson Salamander (A. jeffersonianum), is similar to, and hybridizes with the widespread Blue-spotted Salamander, but it is restricted to scattered sites around the southern Niagara Escarpment, the Greater Toronto and Golden Horseshoe areas, and is generally threatened by destruction of its habitat. The Small-mouth Salamander (A. texanum), is restricted in Canada to Pelee Island, and also part of the hybridizing complex there.
There are two species of Dusky Salamanders, genus Desmognathus, in Ontario, both restricted to the Niagara River Gorge. For decades there’d been attempts to replicate an old record from “across from Buffalo,” but in 1989 James Kamstra and Wayne Weller found Dusky Salamanders in two small streams in the Niagara Gorge, and it turned out that one of these populations was D. fuscus, the Northern Dusky, and the other D. ochrophaeus, the Allegheny Mountain Dusky. We can see the habitat of both of these species, in New York across the St Lawrence River from eastern Ontario, but they never made it across the St Lawrence lowlands to Ontario. Another Stream Salamander species, the Spring Salamander (Gyrinophilus porphyriticus) is known only from three Niagara Peninsula larvae collected in 1877. There is also an old larva of this species supposedly from Britannia, in Ottawa, but decades searching hasn’t turned up a population here.
Eastern Ontario is not a particularly diverse area for salamanders, but the seven species found here have a variety of different life histories and are among our most poorly known Vertebrates.
The Mudpuppy (Necturus maculosus) is Ontario’s largest salamander, reaching a foot or more in total length. These salamanders are permanently aquatic and have feathery gills behind the head, and other features of the larval morphology that other species lose when they mature. Mudpuppies occur in larger rivers and lakes throughout southern Ontario, as far north as Thunder Bay and the upper Ottawa River, though their distribution is poorly known due to their permanently aquatic habits. They’re known from the Rideau, Mississippi, and Madawaska rivers, on the basis of only a few records. The one place they can be easily seen in eastern Ontario is during the winter at Mudpuppy Night in Oxford Mills – http://pinicola.ca/mudpup1.htm – where many Mudpuppies from an abundant population are out in the open during their winter activity period.
The Salamanders with the least surprising life history are the Ambystoma “Mole Salamanders,” so called because they spend much of their lives underground – like frogs these live on land and come to ponds to lay eggs in the spring, which hatch into larvae which, like tadpoles, transform to leave the water to live on land until they come back to breed in ponds as adults.
The Blue-spotted Salamander (A. laterale) is the most frequently encountered species in our area, often wandering into basements or garages, or turned up under wood that has been resting on the ground. Adults are about 13 cm in total length; they are black or dark brown with variable amounts of bluish spots or flecks. This species is closely related to the Jefferson Salamander, which does not occur in eastern Ontario, and the two species hybridized historically to produce unisexual polyploids which contain multiple sets of chromosomes from both the Jefferson and Blue-spotted Salamanders and are almost indistinguishable from the parental species except through genetic testing. These polyploid populations are almost entirely female and usually must mate with a male of one of the parental species to reproduce, though usually rejecting the chromosomes from his sperm. There are also situations, especially in disturbed habitats, where the sperm is incorporated and the number of sets of chromosomes increases as high as seven; these hybrids have the chromosomes of their “parent” species, but the cytoplasm of a southern species which does not occur in Canada; much of the research on these hybrids has been done by Dr. James Bogart and students at the University of Guelph.
At one time the polyploids occurring in eastern Ontario were called a separate species, Tremblay’s Salamander, larger and less spotted than ordinary Blue-spots, with two sets of Blue-spotted genes and one of Jefferson genes; but since it doesn’t reproduce sexually it is no longer considered a separate species.
Our other Ambystoma is the Yellow-spotted Salamander (A. maculatum). This large, blackish Salamander has two rows of large yellow spots on its head and along its back and tail. It can grow to over 20 cm in length. It’s fairly common on the Shield, including Lanark County, but is restricted to mature woods on sandy dunes in the limestone country of easternmost Ontario. The large, slow-hatching, jelly-swathed egg masses are conspicuous in woodland breeding ponds in the early spring.
The Eastern or Red-spotted Newt (Notopthalamus viridescens) has a life-cycle that differs from any other Ontario salamander – the larvae transform into a terrestrial stage known as the “red eft” and spend 2-4 years on land in the woods. They then return to the water to become mature aquatic adults. Adults have expanded tail fins, and are dark above, often a greenish-brown colour, with prominent black-ringed red spots on their sides; efts are orange-red, with the same red spots, but narrow tails. The red colour serves as a warning to predators that the eft is poisonous, and efts are the only Salamanders you’ll see wandering around in daylight. In eastern Ontario the distribution of Newts is very scattered, and they may be declining.
The final, and largest family of Salamanders is the lungless Plethodontidae. We have two specialized uncommon species, and one that is widespread and relatively abundant.
The species with the most specialized habitat is the Four-toed Salamander (Hemidactylium scutatum). In May the females leave their woodland habitat and form cavities in moss, typically Sphagnum, overhanging water, where they lay their eggs. When the larvae hatch they wriggle down through the moss into the water where they live until they transform. Although the Four-toed Salamander has only four toes on its hind feet while similar Salamanders have five, the tiny toes are not a particularly useful identification character – better are the constriction at the base of the tail and the underside which is bright white with bold black spots, quite unlike the greyish underside of the Red-backed Salamander, with which it could be confused. Undoubtedly the species is more common in eastern Ontario than very few old records indicate – you have to go to bogs or other moss-banked ponds or ditches during the breeding season to have the best chance of finding them.
Another small, slender Plethodontid Salamander is the Two-lined Salamander, Eurycea bislineata, almost always found in or very near running water or gravelly seepages. This species is generally gold-coloured with two dark longitudinal stripes down its back. Eggs are laid beneath flat rocks in streams and the larvae live in the stream until they metamorphose. The best way to find them is to flip over rocks just at the edge of a stream or lake. Two-lined Salamanders are not found in southwestern Ontario, but are locally common in a band from Georgian Bay, across Algonquin Park to Quebec, and south to the St. Lawrence River, though they are found east of the Shield in Ontario only in a very few sites where water flows into streams through seepages of clean gravel. Lanark County is part of this range where the species is fairly common; there used to be a population below the dams in Almonte, but the new hydro station has been built over the site where they occurred.
The Eastern Redback Salamander, Plethodon cinereus, is usually regarded as the most abundant Vertebrate in the forests of northeastern North America. These Salamanders act as keystone predators to regulate the invertebrates of the forest floor community, and through them the character of leaf litter decomposition, soil, and nutrient cycling in the forest. Red-backed Salamanders are an exception to the rule that our Amphibians lay their eggs in water, since they lay their eggs in moist spots inside or beneath rotten logs and the entire larval stage of the salamander occurs inside the egg, as they are attended by the mother.
The Small Eastern Plethodon Salamanders, like several other of the common Vertebrates in our forests (Ruffed Grouse, Screech Owls, and Redbelly Snakes), have distinct reddish and greyish colour forms. Rufous and ashy are plausible colours for cryptic forest creatures, as the colours of freshly dead and decayed leaves, and they are produced by the different hues of the melanin pigments – phaeomelanins producing reds and eumelanin grey or black. In Plethodon these morphs are ‘leadback’ – unpatterned and charcoal gray, and ‘redback’ with a reddish dorsal stripe. In New England leadbacks are more frequent in warmer localities, and it has been found that the morphs forage at different temperatures, with a corresponding difference in basal metabolic rates. Across most of southern Ontario populations are mixed, with leadbacks rarely frequent, but in eastern Ontario south of Ottawa and east of the Frontenac Axis there are no redbacks. Reasons for this monomorphic region, or genetic differences between the populations, have not been studied.
Pleistocene ice sheets wiped out any native Earthworms that had lived in Canada, leaving North American species, in the family Megascolecidae, only where glaciation was incomplete, on Vancouver Island and the Richardson Mountains of the Yukon. The 25 or so European species that now live in Canada, in the family Lumbricidae, are thought to have come in the rootstocks of plants imported by settlers or in soil used for ballast in ships. Nowadays, in many Ontario forests, last year’s leaves seems to be all there are…. the rest have been pulled underground and consumed by Earthworms, and increasingly many naturalists have noticed that Earthworms are changing the ecology of forest floors, first in urban parks and now even in protected old growth forests. The missing leaf litter was home to complex communities of everything from snails to Nematodes to Springtails to Centipedes to Beetles to Salamanders, and to the extent that their habitat is gone, the fauna must be gone from the forests with minimal leaf litter. The invasion of wooded areas by non-native Earthworms can also lead to the decline in some native plants, such as rare woodland Orchids that depend on a rich humus layer, as well as facilitating the invasion of wooded areas by non-native plants.
In 2006 James Gibbs and Nancy Karraker found that the frequency of leadbacks had increased with, but faster than, increasing temperature over the course of the 20th century. It’s possible that the excess increase in the leadback morph, above that predicted by climatic warming, may be due to the effects of Earthworms in warming the soil, and in 2010 at the Shaw Woods in Renfrew County this result was found in an Earthworm-ravaged, but otherwise protected, oldgrowth woods, where reduction in litter depth by Earthworms is the main observed longterm disturbance.
Top: Joe Crowley’s photo of a redback (Plethodon cinereus) on Earthworm castings. Bottom: Bev Wigney’s photo of a leadback Plethodon, also on Earthworm castings.
The first way to contribute to our knowledge of Salamanders is through Ontario Amphibian & Reptile Atlas – once you get out into habitat and ‘turn cover’ to discover these creatures, you can report your records online – http://www.ontarionature.org/protect/species/herpetofaunal_atlas.php – or you can co-operate with our effort to resample places where Plethodon have been collected in the past – http://pinicola.ca/thirty/pcin_2012.htm – to see if abundance or colour morph ratio of this species have changed in recent decades.
author’s contact information: Fred Schueler
Bishops Mills Natural History Centre
RR#2 Bishops Mills, Ontario, Canada K0G 1T0
(613)258-3107 <> http://pinicola.ca/
Flying Squirrels—Nocturnal Aviators
Upcoming MVFN Lecture: Thursday, November 17, 2011
The Mississippi Valley Field Naturalists’ (MVFN) public lecture series, Trends in Fauna and Flora, continues November 17 with the third presentation, “Flying Squirrels—Nocturnal Aviators.” You do not need to be an expert to enjoy the presentations—just possess a curiosity or appreciation for wild nature. Cottagers, hunters, fishermen, canoeists, hikers, campers, artists and seasoned field naturalists alike will find something to interest them as we explore what lives in Lanark County and how best to protect it for future generations. Refreshments are offered at each lecture.
This month’s lecture will be presented by Dr. Jeff Bowman from the Ontario Ministry of Natural Resources and also an adjunct professor at Trent University. He has studied flying squirrel ecology in Ontario for years, looking at genetics, habitats, boundary dynamics, population density, and landscape patchworks. Dr. Bowman’s presentation will give us an opportunity to become familiar with these rarely seen relatives of the familiar chipmunk, red squirrel, and grey squirrel.
There are over 40 species of flying squirrels in the world, including the Asian giant flying squirrels, woolly flying squirrels (Pakistan), Winston Churchill’s flying squirrel (Sumatra), dwarf and hairy-footed flying squirrels (southeast Asia), complex-toothed flying squirrel (China), and pygmy flying squirrels (Malaysia). Just two species are found in North America—the northern and southern flying squirrel. Both species are thought to have migrated to our continent across the Bering land bridge, but at different times. The evidence lies in the nature of the baculum (a small bone that supports the penis and facilitates mating). The baculum of the northern flying squirrel is structurally much closer to that of an Asian genus of flying squirrels than to that of the southern flying squirrel.
Northern flying squirrels typically are found in coniferous or mixed forests, while the southern flying squirrel occurs in deciduous and mixed forests. Both species rely on cavities in large trees and are sensitive to forest fragmentation. Thus they are used as indicator species of forest habitat quality in many regions of North America.
Lanark County is home to both kinds of flying squirrels, which are active only at night. Have you ever seen a flying squirrel? In the winter months, I often see them at my bird feeder. A violently-rocking feeder on a still winter night is the tip-off. Closer inspection reveals a pair of flying squirrels which appear to be in constant motion, darting from tree to feeder and back again, their large eyes glowing in the house lights.
So how can you tell these two squirrels apart? Southern individuals have a smaller body size than a chipmunk, while the northern ones are larger than this striped relative. Southern flying squirrels (20 to 25 cm long) have grey brown fur on top with darker flanks and are a cream color underneath. Northern flying squirrels (25 to 37 cm long) have light brown or cinnamon fur above with greyish flanks and are whitish underneath. Still not sure? Come to the lecture and see them up close.
Flying squirrels are fascinating. Depending on the wind and takeoff height, they can glide for 50 metres or more. A skin membrane, called the patagium, is stretched between their relatively long front and rear legs, allowing them to sail from tree to tree. While airborne, they can change direction with the use of their long, flat tail. These arboreal squirrels have sharp, curved claws and hind feet that can rotate 180 degrees while descending a tree. Their large eyes and long whiskers are typical of nocturnal mammals. Flying squirrels often share nests. While a nest typically houses 2-5 individuals, over 50 have been found co-habiting! Nest-sharing is important for conserving energy and maintaining body temperature in the winter, as flying squirrels do not hibernate.
Many species have responded to modern climate change through shifts in their geographic range. A recent study showed that southern flying squirrels in Ontario rapidly expanded their northern range limit in response to warmer winters. This resulted in more overlap with the range of the northern flying squirrel. Not only that, but where they co-occurred, the species interbred and created fertile offspring! This was the first report of hybridization between North American flying squirrel species.
Go squirrelly and learn more about the habits, habitats, and conservation of these dynamic, flightly small mammals. Ponder their response to climate change at Dr. Bowman’s presentation “Flying Squirrels—Nocturnal Aviators” at 7:30p.m. on Thurs. Nov. 17, 2011, Almonte United Church, 106 Elgin St., Almonte. All are welcome ($5 fee for non-members). For further information please contact MVFN’s Program Chair, Cathy Keddy at 631-257-3089.
The results are in, large or small we listed them all!
There was intrigue during the February lecture of the Mississippi Valley Field Naturalists (MVFN) which began with a contest to correctly identify the total number of species found on their first ever 24-h bioblitz carried out in a special local woodland. As Tineke Kuiper progressed through her presentation, A September to Remember: Bioblitz Secrets of the Bell Woodland Preserve, the audience listened attentively as the tally kept rising with additions from each group of species. Where would it stop? Just how many species had been found?
As Dr. Kuiper, ‘tally master extraordinaire’ for the Bioblitz and former MVFN board member explained, a bioblitz is a 24-h survey of the biodiversity of a property. It is part challenge, part social gathering and most importantly, an educational citizen science event. MVFN’s bioblitz started at 3 pm Saturday, Sept 19 and ended at 3 pm Sunday, Sept 20, 2009 at the Nature Conservancy of Canada’s Bell Woodland Preserve near Clayton. The property is deciduous forest on Canadian Shield dominated by Sugar Maple forest, with small areas of mixed hardwoods. While the stream crossing the north end of the property was flowing during the bioblitz, wetlands through which the property drains to the east had no standing water. The weather both days was sunny and cool.
100 participants took part in over 20 one-hour expert-led guided walks. During these walks, experienced and novice naturalists poured over the 95 acre property looking and listening for every living thing. On each walk a photographer was present to record the finds. Experts also searched on their own adding to the species seen. Once sightings were verified, sometimes after further examination, they were added to the tally board and bioblitz database. The final species tally and complete species list have just been published in a report posted on MVFN’s website. As Tineke illustrated in her virtual tour, you don’t need to go any farther than your own forested backyard in Lanark County to see spectacular natural beauty and diversity: the vivid greens of the snakeskin liverwort, the impressively large larvae of the imperial moth, incredible floral diversity, wild and wonderful fungi such as the chocolate tube slime and artists’ conk, the elusive but seemingly numerous red eft, and large mammals ever-present but seldom seen face-on.
As Dr. Kuiper guided us through what the experts uncovered during the bioblitz, the species count on the ‘bioblitzometer’ continued to rise. Among the 30 birds, an early one recorded was the barred owl hooting in answer to Joel Byrne during his ‘Calling Creatures of the Night’ guided walk on Saturday night. Then the next day as walks led by Jeff Mills, Mike Runtz and Cliff Bennett began, the first bird to be seen was the hairy woodpecker, spotted by young bioblitz-naturalist Gillian Larkin. The bird population was much reduced except for a few stragglers which had yet to migrate. Some species such as the owls, woodpeckers, chickadees, blue jays, ravens and crows would remain during the winter, and it was too early for the winter finches to move in. Surprises for the fall were the scarlet tanager, three warbler species, vireos and flycatchers.
The greatest number of species tallied for a single group was 261 for vascular plants (bringing the blitzometer to 291), but this represented just a fraction of the year-round floral biodiversity. Fall species such as asters, goldenrods, daisies, and ferns were well-represented, while spring ephemerals (e.g. trout lily, dutchman’s breeches, spring beauty) which flower before the trees leaf out and shade them, were not seen. Eight of the species observed are considered rare in Lanark County.
Although fungi were very limited due to the bioblitz being held at the end of a warm dry period, there was no shortage. Where but in the fungal kingdom could you find such interesting names as dead man’s fingers, brick tops, witch’s hat, or chicken of the woods? The 58 fantastic fungi included basidomycetes, ascomycetes, a slime mold, and some fungi imperfecti.
Then there were the 50 marvelous mosses and 16 lovely liverworts which overall were indicative of a woodland in good ecological condition. Along with the fungi the count now soared to 415!
Insects were most abundant in the more open areas with asters and goldenrods. 63 species from 8 orders including beetles, bugs, grasshoppers & crickets, dragonflies & damselflies, butterflies & moths, scorpionflies, flies and bees were found. Due to the cold weather moth traps were not set up at night, so any moths recorded were from larval observations. With considerable adeptness, Chris Schmidt shook saplings and caught the ‘rain’ of Lepidopteran larvae (caterpillars) in a large four-cornered umbrella net for later identification.
Seventeen species of invertebrates without 6 legs, (i.e. excluding insects), were found including 4 millipedes, a clam, 4 snails, 2 slugs, an earthworm, a sowbug, 3 spiders and a mite.
Nine amphibian species were seen or heard including the blue-spotted salamander, northern two-lined salamander, red-spotted newt, American toad, gray treefrog, spring peeper, green frog, northern leopard frog and wood frog. Due to the lack of much permanent water, conditions were not suited to turtles and none was found. The two reptiles found were both snakes—a gorgeous smooth greensnake and an eastern gartersnake.
The mammals enumerated were seen, heard or identified by tracks and/or droppings. Combined with the insects, invertebrates, amphibians and reptiles, the addition of 19 mammals brought the bioblitzometer to 525. One of the first mammals recorded was a coyote which called back in answer to the howls from participants on the Saturday night walk. To inventory small mammals such as mice, voles and shrews, two lines of live traps, bait and track tunnels (containing tracking paper smeared with black stove polish and oil to ‘capture’ foot prints) were set up the day before the bioblitz. The number of footprints showed that small mammals were present at a relatively high density.
Interestingly, despite the majority of the area being upland Sugar Maple forest, one fish species was found in the stream on the property—the Bluntnose Minnow.
At this point the tally reached 526—the total number of all species seen in the 24-hr period and it was time to identify the contest winner. Howard Robinson, who guessed 518 (just 8 species short) was closest to this number and won a copy of Earth, Water, Fire: An ecological profile of Lanark County by Paul Keddy.
The bioblitz was an ambitious undertaking and Tineke Kuiper thanked all those involved for their enthusiasm as well as the experts for their vital role in the event. To view a copy of the entire bioblitz report prepared by MVFN, listing all species identified and filled with gorgeous photographs, please visit MVFN’s website at www.mvfn.ca.
Mississippi Valley Field Naturalists
March 26, 2008
Submitted by Pauline Donaldson
MVFN’s recent lecture explored why turtles outlived the dinosaurs but are now in trouble in Ontario
Photo: David Seburn discusses local populations of Blanding’s turtles with a carapace after MVFN lecture. Photo by Howard Robinson
Ecological consultant David Seburn was guest speaker March 20th for the 6th lecture in Mississippi Valley Field Naturalists (MVFN) series “Our Natural World: Conservation Challenges.” The lecture focused on Ontario’s turtles which Seburn describes as ‘endlessly fascinating’. As a species they have been around for so long they saw the dinosaurs go extinct! This is especially remarkable when one considers the relatively few species of turtles worldwide and only eight in Ontario.
The turtle’s shell, perhaps their best known and most unique feature, represents a serious biological limitation, Seburn explained. “They are enclosed in a little box so when they breathe they must compress their organs.” And when they need to pull in their head and limbs for defense, they have to hold their breath! Egg-laying is also a challenge. Not surprisingly the females tend to be larger than males to make room for eggs.
Seburn took the audience through the characteristics and distribution of Ontario’s eight turtle species and the conservation challenges they face. Interestingly, though loss and fragmentation of Ontario’s wetlands was one challenge highlighted, habitat protection did not dominate the discussion. Neither was the threat of global warming a major concern as we are at the northern limit for these reptiles’ successful egg hatching, so warmer temperatures could be beneficial. Why then, are six of Ontario’s eight turtles on the Canada’s ‘species at risk list’? As Seburn explained, Painted turtles and Snapping turtles are doing well. However the large Map turtle is of ‘special concern’ and the Spiny softshell, the Stinkpot, the Blanding’s and the Wood turtle are all considered ‘threatened’. The spotted turtle is in more serious trouble listed as ‘endangered’. It is rarely seen now.
Clues to the answer are the increasing adult mortality rate and the survival of eggs. Once turtles reach adulthood they can live a long time, and have the potential for a surprisingly long reproductive life combined with low rates of adult mortality. However, the natural success rate for eggs is so low that adult mortality must be kept at only 1-2% to maintain population stability. Unfortunately increasing adult mortality from road hazards has become a major problem when turtles travel on land to lay eggs or move to different food sources. The Blanding’s and Wood turtles are quite terrestrial and can travel 1-2 km to nest. Secondly, exacerbating a naturally low egg success rate is increasing predation from overpopulations of ‘subsidized’ predators such as raccoons in parks. Reaching more than 4 times regular rural numbers they can eat 100% of any turtle eggs in an area. Sadly sometimes the only warning sign a population is in trouble is it’s disappearance as all the adults eventually die off leaving no young.
Seburn made some suggestions to help conserve Ontario’s turtles. Short of closing down roads, municipalities can use drift fences or culverts to channel turtles across roads, and perhaps turtle crossing signs. Individuals can help turtles cross roads in the direction they were going (do not handle snapping turtles -lift them with a shovel). Large ‘ecopassages’ have been used in some places with great success in reducing mortality of a wide range of wildlife species. Recovery strategies for Ontario’s turtles also include research and population monitoring.
Info. from Seburn on identification and reporting turtle sightings has been posted on MVFN’s website (see Turtle Watch 2008 filed under Conservation). Turtle sightings can be reported locally to Mississippi Valley Conservation or to the Toronto Zoo Turtle Tally project by calling 416-392-5999.
‘Focus on Mammals’ by Glenn Desy (MNR) will be the last lecture in MVFN’s Conservation Challenges series, Thursday April 17th at 7:30 pm at the Almonte United Church Social Hall in Almonte. For more information, please contact Joyce Clinton at 613-257-4879 or visit MVFN’s website at www.mvfn.ca.
Mississippi Valley Field Naturalists
Submitted by Pauline Donaldson
November 19, 2007
Last Thursday an enthusiastic crowd gathered at Almonte United Church to learn about our nine Eastern Ontario snakes from Tobi Kiesewalter at the Mississippi Valley Field Naturalists (MVFN) lecture. ADHS teacher Mike Keffer introduced Tobi who had just returned from New Zealand where there are no native snakes!
Kiesewalter has been studying and educating people about snakes for more than 10 years as
naturalist at Murphy’s Point Provincial Park, and his enthusiasm on the topic was infectious. He
works hard to get out the Park’s message “live and let slither” on behalf of the 9 species that call
Eastern Ontario home. Key conservation issues which emerged included maintaining habitat and
increasing awareness of risks snakes face from road hazards and human persecution. Although
none of Eastern Ontario’s snakes pose a danger to humans, as Tobi explained, they are often
misunderstood or feared because they are rarely seen or when seen they may be mistaken for a less
benign species. Our Northern Water snake for example may be mistaken for the venomous water
moccasin. The Eastern milk snake may be encountered acting aggressively while shaking its tail
against dry leaves, and be incorrectly identified as a rattlesnake.
The evening began with an excellent video, Black Ratsnake Conservation in Ontario, filmed in St.
Lawrence Parks and Murphys Point Provincial Park and featuring university researchers and
Ontario Parks staff conducting research on this species considered ‘threatened’ in Ontario. The
snakes were seen climbing trees, being measured or implanted with tracking devices and having
their over-wintering hibernaculums monitored. Tobi donated a copy of the 20-minute video to
MVFN, who is pleased to loan it out. Sightings of rare black ratsnakes can be reported to the
Natural Heritage Information Centre at http://nhic.mnr.gov.on.ca.
Tobi followed the video with fantastic slides of other snakes. The audience learned the difference
between black ratsnakes and the northern water or eastern milk snake, and the northern brown
versus the northern redbelly. There were also wonderful photos of white half moon markings in
front of the tiny northern ribbon snakes’ eyes and of the elusive but beautiful smooth green snake.
Tobi showed us that our snakes are a tough bunch. They survive in spite of challenges of being
‘ectotherms’ in our cold climate, thanks to adaptations and to the proper habitat still being found
here. Forest edge habitat is critical since to regulate body temperature they need both cooling
forest shade and open areas for basking in the sun. In winter black ratsnakes congregate in
communal burrows or hibernacula and they return to the same ones year after year. Therefore they
should never be relocated more than 100-200 metres away because they will die when winter
comes. Temperature regulation is also important in the summer. Eggs layed in carefully chosen
nests will require 10 weeks of 30 degrees C to develop. Therefore it is critical to not disturb rock
piles, rotting stumps or standing dead trees.
Surprisingly, although it is generally rare for snakes, five Eastern Ontario species do not lay eggs
at all but give birth to live young. The live-bearing or ‘gravid’ females can control the temperature
of developing young by regulating their own temperature. As a consequence, however, hazards of
the road are even more serious for these species if a gravid female is involved.
Following the slides, Tobi brought out the 20-year-old, bred-in-captivity black ratsnake which had
accompanied him to Almonte and challenged those uncomfortable around snakes to hold the
animal. The snake was seen moving from person to person, checking its route with a constant flick
of its forked black tongue drawing in traces of a chemical trail to determine if it was going right or
The public is invited to the next lecture of MVFN’s “Conservation Challenges” series January 17,
2008 with Jean Lauriault of the Canadian Museum of Nature who will focus on Butterflies. For
further information please contact MVFN’s Program Chair Joyce Clinton at 613-257-4879 or see
MVFN’s website at http://mvfn.ca.