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.