submitted by Fred Schueler, Fragile Inheritance Natural History
Calendar-bound traditions usually have a macabre holiday on a fixed date in the fall, often enlivened with orange and black geegaws bought in stores. In the seasonal ritual calendar for eastern Ontario naturalists, the corresponding autumnal ceremony is “Burn Henry Ford in Effigy Night” (BHFIEN), a festival of revulsion and disgust at the slaughter automotive transportation imposes on the populations of any animal that needs to move across the landscape. The date varies from year to year, and is the night when Leopard Frogs (Lithobates pipiens) make their major movement from the fields where they spend the summer towards the waterbodies where they hibernate.
This memorial was first marked on 13 October 2000, when, on County Road 18 from Kemptville to Bishops Mills (20h30-20h50, 13° C, calm, a trace of rain), there were great numbers of dead and not-yet-dead Leopard Frogs at all the traditional killing fields: just south of Kemptville, near the turn to Oxford Mills (and doubtless in the village), Hutchins Corners, the place where the drain from the Wolford Bog crosses the road, from the County Road 20 Bridge past the Middle Creek Bridge to the drain just past where Nelms used to live, in the fields between the Cemetery and Bishops Mills, and, in lesser numbers, on the streets in the village.
In the years since, BHFIEN has been seen to occur earlier in years that have had wet summers, so the frogs have made good growth, and are ready to go into hibernation, and later after drought summers, when they feel the need to gulp down a few more Grasshoppers in order to be ready for winter.
In Bishops Mills, there have been few Leopard Frogs since the winter of 2013-2014, but this year there’s been a very considerable recovery, and there were good numbers along County Road 18 on September 13, so I expect the combined celebration and lamentation of a “good” BHFIEN. The best nights for the frogs occur when rain starts up late at night when there’s not much traffic, and the worst when dusk on already wet roadsides coincides with the going-home-from-work traffic.
The places where frogs cross roads in their seasonal movements can vary as much as a kilometre from year to year, depending on the temperature and moisture. North Grenville’s municipal budget for this year includes some funding for studying where Turtle Crossing signs can alert drivers that Turtles may be on the road, but it’s much harder to avoid hitting frogs. All you can do is, if it’s possible, not take trips early in the evening on rainy nights in the fall, drive slowly when you see frogs on the road, and swerve around those you can safely avoid, but a study in Germany suggests that at any speed above 30 km/h, just the passage of a vehicle is going to kill many frogs.
Science-based festivals are naturally marked by data collection, and any reports of frogs-on-the-roads sent to me at [email protected] will contribute to our understanding of the populations and their movements.