#WBTC1 #EvoBeh2 For greaterhorseshoe s, sociality follows an annual in which ⚥ are largely segregated during the summer, before associating together during winter. Interestingly, only ~40% of s form these winter “clusters” each year. Why are some s social & others not?

2) #WBTC1 #EvoBeh2 Over 4 years we studied a population of GHBs at 14 underground sites in Gloucestershire, UK. Morphometric measurements, age, and reproductive status were recorded for every , in addition to whether the bat was alone or in a group.

3) #WBTC1 #EvoBeh2 Clustering s tended to be younger w/ lower energy reserves vs their solitary counterparts. Why might this be? 1 hypothesis is that grouping improves survival rates of juveniles. Juvs face a particularly high risk of starvation over winter…

4) #WBTC1 #EvoBeh2 with later born young being most disadvantaged. Mortality risk can be mitigated by synchronising arousal to suitable foraging conditions, through careful selection of a roosting position that matches ambient temp. and alignment of s to dusk.

5) #WBTC1 #EvoBeh2 Where do clusters come into this? Grouping may be an additional mechanism through which GHs can efficiently time their arousal. Perhaps arousal is even more effective having noisy neighbours to wake you up. Future work with thermal imaging seeks to test this.

A big thank you to all of the brilliant scientists . A lot of very interesting greater horseshoe bat research awaits - stay tuned!