Can the Rothamsted suction-traps be used to test the relationship between bat activity and nocturnal aerial insect abundance?

This is the second rotation associated with SWBio DTP. I used passive acoustic detectors and a Rothamsted suction-trap to investigate the relationship between bat activity and nocturnal insect abundance. I tested the effect of insect abundance, meteorological variables, and distance from the trap on bat activity. I also investigated the relationship between aphid abundance, the main remit of the suction-trap network, and nocturnal insect abundance, to see if we could use aphid abundance as a proxy for nocturnal insect abundance. I found the signs of a strong positive relationship, indicating that aphid abundance could be used as a proxy for nocturnal insect abundance. This finding will allow suction-traps across the UK to be used as measures of insect prey availability to bats.

Bats are used as indicators of healthy terrestrial and aquatic ecosystems. Understanding their role in the food web is therefore an important part of conservation and protection of entire ecosystems. In the UK, all 17 breeding bat species are insectivorous.

I found a weak negative relationship between nocturnal insect abundance and bat activity. Site had a significant impact on bat activity, suggesting sites varied in habitat, microclimate and proximity of roosts. I also found a significant positive relationship between aphid abundance and nocturnal insect abundance, indicating that aphids could be used as a proxy for the availability of bat prey in future studies.