Floating Bottle Traps

Keep up to date with our new survey techniques.

Now the busy survey season has come to an end for the year we have the opportunity to discuss some of the new survey methods we have been trialling. The first is the use of floating bottle traps for great crested newt surveys.

Bottle Trapping Background

Bottle trapping is considered to be one of the most reliable and effective methods for surveying for great crested newts, especially in turbid and heavily vegetated ponds where torching isn’t effective. The traditional method of bottle trapping uses a funnel or bottle trap attached to bamboo canes which are pushed into the substrate along pond margins. The traps are set at dusk and then checked the following morning for great crested newt adults or larvae. Using bamboo canes to set out the traps means that this type of bottle trapping cannot be used on ponds with liners or hard substrates. This is a problem in cases where torching is ineffective as without bottle trapping the survey effort may be insufficient to be confident that the presence or likely absence of great crested newts can be determined.

Floating Bottle Traps

This year we have tested the use of a new floating bottle trap to solve this problem. This design uses foam to float the bottle at the correct angle on the water meaning that there is no need for bamboo canes and enabling us to use bottle trapping in lined ponds. The traps are tethered to the bank to make sure they don’t float away.