What's Happening At Our Vernal Pools?

As everyone is probably aware, the weather has been very strange. The fall and winter were unusually warm and dry and with the exception of the bizarre October snowstorm, virtually snow free. The spring has also been unusually warm and dry and March was one of the warmest ever recorded. Rainfall in March and April should average about an inch a week and we have had nothing but light and spotty rain instead. As a result of the unusual weather, this year the spotted salamander migration seems to have been limited to the few rain events that we had in late February and early March and mostly late at night. This is the first time in the past 8 years since we started closing the road and protecting the salamanders that I can ever recall not being able to observe even one really good night of migration.

For anyone that follows our updates on the Friends website or that met us on the road, they know that the weather made predicting the migration almost impossible this year. We closed the road just about every time that NOAA or the other weather outlets had even a slight forecast of afternoon or evening rain just to be on the safe side. While we didn't see many salamanders crossing the road when we were out there, early morning checks also didn't show any mortality, including on nights when we chose not to close the road. So at least our efforts were protective of the population despite the complexity of the weather.

We know some salamanders migrated to the pools and bred because we did see some crossing the road in late February and in early March and we saw a fair number of egg masses in the water a few weeks ago. However, the sustained dry period we are in is rapidly causing the pools to dry and they are at the lowest water level I can remember. Areas that would normally be inundated with anywhere from 6 inches to 2 feet of water have no water and other areas are much shallower than normal. The outer limits of water in the big pool are at least 50 feet less than they normally would be at this time of year.

In a previous post about our vernal pools I called them the and they truly are from an ecological standpoint. Without the vernal pools and their water, many species of amphibians and other aquatic creatures would not have a place to breed. Extreme dry weather places a significant burden on the species that rely on the vernal pools. With a diminished area of water, predators can more easily find their prey and there is simply less room for all of the inhabitants to use. In ecological terms this is called "carrying capacity" and the less open water in the pool, the less "carrying capacity". In nature something always has to give and those species less able to survive in a smaller space of open water for a myriad of reasons will succumb. Fortunately our pools feature some areas that are quite deep and even now continue to have a good amount of water. But if this dry weather continues even these areas will become smaller, challenging anything trying to survive in these limited areas. But nature always seems to have a way to persevere and this year, dry weather or not, will be no different.  

Hopefully we will get some rain and the vernal pools will be filled this summer with dragonflies and frogs and salamanders and turtles and all kinds of other creatures that rely on the "oasis in the forest". Stay tuned, I suspect there is much more to come....The Friends will likely lead a vernal pool walk in May or June if the weather cooperates and we get some rain. But it will only be open to Friends members. If you haven't joined the Friends yet, its FREE so why wait? Just register on the Friends website at www.friendsebec.com