We are having some issues with pitfall trapping in areas where the ground water is very close to the surface. In many palces, as soon as we put a pitfall trap in the ground it fills with water from the ground. In other places the traps fill with ground water after a heavy rain event meaning we lose traps to flooding. All of the traps have rooves to protect them from rain and debris but we're losing lots from ground water infiltration.
Has anyone found a way to get around this issue so that the ground water doesn't fill the traps?
I have seen some of the small wildlife traps to collect small organisms. I used roof gutters in an erosion study, and perhaps the gutter companies could construct traps to meet your need. Otherwise, whether you find suitable plastic buckets or use plastic underlayment as used in water feature landscaping, you might be able to keep groundwater water out, but have to bail them out if flooded.
What about using an alternative if pitfallls are not working for the site conditions. Winkler or Tullgren extraction?
I am not sure to answer for this question , because I am from Afghanistan , Afghanistan is a land loged country with dry climate , Again, I can give you such an answer that may not be correct, it is a guess, it may be correct according to you.How to make a pifall trap , please follow the under measurement;
1. Choose a location for your trap on flat ground near vegetation.
2. Use a trowel to dig a small hole.
3. Place a clean yoghurt pot in the hole. Fill in any empty space around the pot with soil. Make sure that the top of the pot is level with the ground, or you won't catch anything.
4. Leave your trap overnight. If you prefer to leave it during the day, check it at least every few hours.
5. Empty the trap into a tray to see what creatures wandered in.
6. Record your findings: make a note of what you caught, the date and location. You could also draw the creatures or take photographs.
7. Carefully release the creatures, returning them to a safe, sheltered place.
One possible solution to prevent pitfall traps from filling with groundwater is to use a waterproof membrane or liner to create a barrier between the trap and the surrounding soil. This could be a plastic liner, a layer of bentonite clay, or another waterproof material. The liner should be large enough to extend beyond the edges of the trap and be anchored in place with stakes or rocks to prevent water from seeping under the edges.
Another approach could be to modify the design of the traps to make them more resistant to groundwater infiltration. This could include using taller walls or adding a bottom to the trap to create a deeper pit that is less likely to fill with water. Alternatively, you could try installing the traps on mounds of soil or gravel to raise them above the groundwater level.
Another option would be to use alternative trapping methods that are less affected by groundwater, such as funnel traps or flight intercept traps. These traps are typically suspended above the ground or hung from trees, and are less likely to fill with water even in areas with high groundwater levels.
It's also important to consider the timing of trap installation and monitoring in relation to local weather patterns and groundwater levels. If you can anticipate when the traps are likely to flood due to heavy rain events or seasonal changes in groundwater levels, you may be able to adjust your trapping schedule or modify the traps accordingly.
Ultimately, the most effective solution may depend on the specific conditions and constraints of your study area. Experimenting with different trap designs, materials, and installation methods, as well as consulting with local experts, may help you find a solution that works for your situation.