Mitigating road mortality of diamond-backed terrapins (Malaclemys terrapin) with hybrid barriers at crossing hot spots

Published source details Crawford B.A., Moore C.T., Norton T.M. & Maerz J.C. (2017) Mitigating road mortality of diamond-backed terrapins (Malaclemys terrapin) with hybrid barriers at crossing hot spots. Herpetological Conservation and Biology, 12, 202-211.
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This study is summarised as evidence for the following.

	Action	Category
	Install barriers along roads/railways Action Link

Install barriers along roads/railways

A controlled, before-and-after study in 2009–2014 on a causeway over a saltmarsh in Georgia, USA (Crawford et al. 2017, same experimental set-up as Crawford et al. 2018) found that installing a roadside barrier with nest boxes reduced diamond-backed terrapin Malaclemys terrapin road crossings. Numbers of crossings by terrapins were lower at the site after the barrier was introduced (2–7 crossings) compared to before (10–17 crossings) and compared to sites without the barrier (12–109 crossings). Three monitoring locations along the causeway were selected based on high terrapin road mortality levels in 2009–2010. Two sites (331 m and 310 m long stretches of road) without barriers were monitored, and at a third site (162 m long, between the other sites) a barrier was installed in 2011. The barrier was 22.9 m long, positioned 5 m from the roadside and comprised short mesh fencing and six nest boxes. Terrapins were monitored on the road at all three sites every 20–90 minutes, between 08:00 and 20:00 from May–July in 2009–2014. Two years of pre-barrier and four years of post-barrier data were collected.

(Summarised by: Katie Sainsbury)