After leaving Portage la Prairie, we took a side trip up to the famous garter snake hibernation site at Narcisse. Many people over the last few weeks have been asking us about them, and we recently spoke with someone who told us that the snakes have started to return to these hibernation sites, or hibernacula, already. So, we decided to check it out for ourselves. Considering we had only seen one live garter snake since leaving Ontario a month ago, it was pretty amazing to see so many snakes!
Sadly, there were many (as in hundreds) that were dead on the road, especially through the town of Inwood, where there is apparently a similar but lesser known hibernacula complex. Near Narcisse, efforts have been made to reduce the numbers of road-killed snakes, by running drift fences on either side of the highway. These fences are not dug into the ground, so they don't stop all of the snakes, but they do seem to block a good number of them. The snakes are then directed by the fences to culverts which have been installed under the highway. It seems to be at least partially reducing the roadkill numbers if the evidence we saw is any indication. Structures like this are very expensive to install, however, so they may not be a workable solution in every area where significant road mortality of wildlife occurs. Also, it has been shown that some species will not use culverts, etc. Much more effort is required to mitigate the damage our road networks are doing to our natural heritage. From the cost side, it would be much cheaper to install features like culverts, ecopassages, etc. when a road is being constructed in the first place, rather than trying to retrofit them later.
When we actually got to Narcisse (http://www.flickr.com/photos/scisnake/222529190/ ), we walked the trails and found lots of red-sided garter snakes sunning themselves on the paths, and there were hundreds around some of the 'pits'. These pits (http://www.flickr.com/photos/scisnake/222529191/ ) are small sinkholes in the limestone with many crevices that extend down below the frost line. This creates an exceptional hibernation site for the snakes, and these pits actually hold the world's highest concentration of snakes. A pretty amazing place, of which Manitoba is justifiably proud! We are relatively used to seeing lots of snakes around, both in captivity and in certain locations in the wild, but not like this. There were red-sided garter snakes (http://www.flickr.com/photos/scisnake/222529191/ ) everywhere, and this was only a small portion of the numbers that can be seen in the spring, when all of the snakes emerge over a fairly short period of time! We'll have to come back and see that someday!