The table suggests that more is better, but if you are observant you will notice that gains in precision decrease with increasing sample size, i.e. each new frog that you catch will increase the precision of your estimate but not by as much as the last one. Collect at least 60 individuals if your you are finding that approx. If you will be working in foul weather consider printing the forms on water proof paper. Making the Catch and Recording Data Froglets tend to congregate in groups along the edge of the wetland. Some have found that different nets work best for different sites, and having a large net and a small net in hand can be useful for herding frogs.
Some sites have such dense vegetation that capturing frogs with nets is nearly impossible.
A group surveying at Mason Neck Refuge in Virginia encountered such a problem so they tried electrofishing. This method proved effective and caused no apparent mortality. Seining with a fine mesh net can also be effective. Holding the frogs prevents recapture bias. As froglets are captured they can be placed in buckets that have a little water from the site in them, or in a moistened pillow case tied to your belt.