to Herpers: conditions for seeking migrating amphibians
Herpers, I have been watching the weather forecast carefully for tonight to see if it would be a good night for amphibian migration. I look for a few predictors.
- I want to make sure that where I am going to look for amphibians has some open ground that is snow free. Amphibians will certainly move over snow, but they will primarily be coming up out of those patches of open ground. I also want to see that the edges of shallow ponds have melted.
- I look for night-time temperatures above 32 F. Sometimes I see a minimum temperature of 40 F given for amphibian movement, but that is a myth. You could see significant migrations with any temperature above freezing. I have seen amphibians move during wet snows. However, the warmer the better. If all of a sudden the night-time temps soar to 50 F, and other conditions are all favorable, you will see more amphibians and greater diversity of species.
- I want the ground and the roads to be wet. The wetter the better. We frequently see significant migrations after the rains have stopped, as long as the roads and woods are still wet. Sometimes amphibians will move even though the roads have dried out after a rain earlier in the day. Usually this only happens if the ground is still very wet and the temperatures are relatively warm.
So, how does tonight stack up in your area? Are there open patches of ground in your woods? Have the edges of shallow ponds thawed out? Will the temp stay above freezing? By how much? Does the forecast show significant rain starting before dark and continuing after dark?
Although temps will only be in the mid-30’s tonight here in the Lake Champlain Basin and some areas have snow in the forecast, I continue to think there will be amphibian movement tonight in warmer areas and at low elevations where the above conditions are met