Bat monitoring

Why monitor bats

Bats are important biodiversity indicator species and observing changes in their population can be used to monitor the health of ecosystems and the impact of climate change. 

With a single bat able to consume 1,000 flying insect in a night, they certainly provide a valuable environmental role.

Bats use a variety of roosts during their lifetime including trees and buildings. Monitoring our local bat populations increases our knowledge of their status and distribution.

Jersey is a signatory to a number of national and international biodiversity and monitoring agreements and surveying bats helps to fulfil our obligations under these agreements. In this way Jersey is also contributing to global information on biodiversity.

iBats monitoring programme

By surveying bats every year we can begin to build up a picture of how the bat population in Jersey is doing.

We survey bats with a bat detector and GPS device. Our Natural Environment officers, with the help of volunteers, drive 11 routes on the Island at night time during July and August to record bats. We can record exactly where a bat was heard and we can even detect what species of bat it is.

Jersey has 17 known species of bat, and more than half of these can be detected using this method.

Bat research findings

An interim report in 2016 showed that the two most common species in Jersey had increased between 2011 and 2015, however it was unable to detect population changes for other species including rare or difficult to detect species.

10 years of data is needed to understand any increase or decrease in population numbers and this will be done using the most easily detected species such as the Common pipistrelle.

Research is ongoing into methods to investigate the trends of these species.