When broadcasting bait for California ground squirrel management, aim to distribute approximately 4 kernels per square foot. A calibrated spreader is essential to successful broadcast baiting.
How to Calibrate a Bait Spreader
1. Designate a test area that is at least 25 feet long and 4 feet wide (find a clean, flat area or lay out a tarp).
2. Fill the hopper of the spreader with clean oats and walk through the center of the test area (starting at a short side) while turning the crank at a fixed rate per step (start turning the crank before you reach the test area and continue until you have cleared the test area).
3. Count the number of oats in random 1-square foot sections along the entire length of the 25-foot test area. Record the number of oats counted in each square. Count 20 random squares from one end to the other (it is important to count random squares and not just the areas where the most oat kernels lie).
4. Calculate the average number of oats per square foot for this trial run.
5. Repeat steps 2-4 at least four more times.
6. Calculate the average number of oats per square foot for all five trials. Compare this average to your goal of 4.13 oats per square foot. Adjust the spreader accordingly until your average and your goal are similar.