Project update 2017
Trapping and Tracking
There were 18 trapping sessions carried out at 10 sites in 2017: 198 bats were caught of 6 species (28 Nathusius pipistrelles - 21 males and 7 females)
River Wansbeck Roost
The mixed Soprano/Nathusius pipistrelle river roost in the village near Morpeth started to form during the third week of April and numbers increased to a peak of 41 Nathusius pipistrelles, which was an increase of 10-12 from 2016. This was before any pups were born. It is definitely a challenge trying to get accurate counts from a mixed species roost!
Mating Roost – Coastal village
A static detector has been monitoring activity at the mating roost that was discovered a couple of years ago by radio tracking a post lactating female. There has been frequent flight activity with occasional male social calls during the summer and during August there was a significant increase in male advertisement calls.
One female caught at Ladyburn Lake, Druridge Bay Country Park on 20th May 2017 was the required condition and weight so was tagged and radio-tracked. She was in a detached flat roof garage with 5 other Nathusius pipistrelles but after a few days of monitoring managed to get her tag off. However 6 Nathusius pipistrelles were counted out of our known coast roost a couple of days later so this is possibly the same group.
The numbers increased over the next 14-17 days to 13 then 24. On 26th June the adult bats emerged between 2200 and 2240 and pup contact calls could be heard during the next half hour still in the roost. From the data collected from an anabat express left in the loft near to the roost site it is likely that the pups were born around 11th June.
There is still a great deal of data to analyse, but it was useful to know from a static detector recording close to the maternity colony that the bats finally left the roost at the end of July.
Photos: D. Jarema