Individual study: Effects of cave gating on population trends at individual hibernacula of the Indiana bat (Myotis sodalis)
Crimmins S.M., McKann P.C., Szymanski J.A. & Thogmartin W.E. (2014) Effects of cave gating on population trends at individual hibernacula of the Indiana bat (Myotis sodalis). Acta Chiropterologica, 16, 129-137
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Install and maintain cave gates to restrict public access
A replicated, before-and-after study in 1979–2009 of 20 caves in the USA (Crimmins et al 2014) found that installing cave gates resulted in population increases or decreased rates of decline for 13 of 20 colonies of Indiana bat Myotis sodalis. Thirteen of the populations were declining before cave gates were installed, and either increased (8 populations) or continued to decline at a reduced rate (5 populations) after installation (data reported as results of statistical models). Seven of the populations were increasing before cave gates were installed, and either declined (4 populations) or continued to increase at a reduced rate (3 populations) after installation (data reported as results of statistical models). Annual population counts were carried out between 1979 and 2009 using a standard protocol before (during 4–15 years) and after (during 4–16 years) installation of cave gates. All caves had average populations of >100 individuals. Change-point detection modelling was used to estimate population trends. The authors state that confounding factors, such as gate design, human activities and regional differences are not accounted for.
(Summarised by Anna Berthinussen)