Study

Integrated analysis for population estimation, management impact evaluation, and decision-making for a declining species

  • Published source details Crawford B.A., Moore C.T., Norton T.M. & Maerz J.C. (2018) Integrated analysis for population estimation, management impact evaluation, and decision-making for a declining species. Biological Conservation, 222, 33-43.

Actions

This study is summarised as evidence for the following.

Action Category

Use signage to warn motorists about wildlife presence

Action Link
Reptile Conservation

Install barriers along roads/railways

Action Link
Reptile Conservation
  1. Use signage to warn motorists about wildlife presence

    A before-and-after study in 2009–2015 on saltmarsh in Georgia, USA (Crawford et al. 2018) found that adding a flashing terrapin-warning sign to alert motorists and partially fencing a causeway reduced the likelihood of mortality for diamondback terrapins Malaclemys terrapin crossing the road. When the flashing signs and hybrid nestbox-fence barrier were installed on a road, survival of crossing female diamondback terrapins increased from 24% to 53% (data reported as statistical model outputs). In 2011, a 22 m hybrid nestbox-fence barrier was built along a 9 km long causeway. In 2013, two terrapin crossing signs with flashing warning beacons were added to warn motorists entering a 6 km stretch of causeway. The signs were activated for 2 hours/day during peak terrapin crossing times. Terrapins were surveyed on the causeway and in adjacent creeks during the nesting season (May–July) in 2009–2015.

    (Summarised by: Katie Sainsbury)

  2. Install barriers along roads/railways

    A before-and-after study in 2009–2015 on a causeway over a saltmarsh in Georgia, USA (Crawford et al. 2018, same experimental set-up as Crawford et al. 2017) found that installing a roadside barrier with nest boxes and adding a flashing terrapin-warning sign to alert motorists reduced likelihood of mortality for diamondback terrapin Malaclemys terrapin crossing the road. When the hybrid nestbox-fence barrier and flashing signs were added to a road, survival of crossing female diamondback terrapins increased from 24% to 53% (data reported as statistical model outputs). In 2011, a 22 m long hybrid nestbox-fence barrier was built along an 8.7 km long causeway. In 2013, two terrapin crossing signs with flashing warning beacons were added to warn motorists entering a 6 km stretch of causeway. The signs were activated for 2 hours/day during peak terrapin crossing times. Terrapins were surveyed on the causeway and in adjacent creeks during the nesting season (May–July) in 2009–2015.

    (Summarised by: Katie Sainsbury)

Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 19

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.


Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust