Use nest covers to protect against human disturbance

How is the evidence assessed?
  • Effectiveness
    not assessed
  • Certainty
    not assessed
  • Harms
    not assessed

Study locations

Key messages

  • Two studies evaluated the effects of using nest covers to protect against human disturbance on reptiles. One study was in the USA and one was in Greece.



  • Reproductive success (2 studies): One of two replicated, controlled studies (including one paired study) in the USA and Greece found that loggerhead turtle nests that were covered with cages had similar hatching success compared to nests that were not covered. The other study found mixed effects of cages on hatching success of loggerhead turtle nests.


About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

  1. A replicated, controlled, paired study in 1996 in beaches in Florida, USA (Mroziak et al. 2000) found that covering loggerhead Caretta caretta turtle nests with individual cages did not improve hatching success in areas with high or low human footfall. Hatching success was similar between caged and uncaged nests in areas of high footfall (caged: 66–67%, uncaged: 66–71%) and low footfall (caged: 75–76%, uncaged: 66–76%). In May–October 1996, fifty-eight paired sea turtle nests were either uncovered or covered with square wire cages (76 cm square, 107 cm tall, 5 x 10 cm mesh) anchored 30 cm in the sand in both low (66 total nests, 4,209 caged eggs, 3,888 uncaged eggs, 20 beach users/hour, two beach zones) and high traffic beaches (50 total nests, 3,678 caged eggs, 4,991 uncaged eggs, 50 beach users/hour, two beach zones. Hatching success was determined by excavating nests three days after hatchlings emerged to count successfully hatched eggs.

    Study and other actions tested
  2. A replicated, controlled study in 1987–1995 on a sandy beach on Zakynthos Island, Greece (Kornaraki et al. 2006) found that covering loggerhead turtles Caretta caretta nests with individual metal cages resulted in variable hatching success compared to both uncaged nests left in situ and nests relocated to an on-beach hatchery.  Over six years, hatching success in caged nests was lower in two years, higher in two years and similar in two years compared to in situ nests. Hatching success for caged nests varied from 44–72%, compared to 56–68% for uncaged in situ nests and 51–75% for nests moved to an on-beach hatchery. From 1988–1995, nests located within 7 m of the sea and in danger of inundation were moved to a beach hatchery (77 nests) as were nests located near invasive plants which had root systems that grow into nests. From 1990, nests located in beach areas with tourists were protected by 50 cm circular metal mesh cages buried 15 cm in the sand (88 nests). A further 313 nests were left uncaged and in situ. Nests were excavated following hatchling emergence to assess hatching success.

    Study and other actions tested
Please cite as:

Sainsbury K.A., Morgan W.H., Watson M., Rotem G., Bouskila A., Smith R.K. & Sutherland W.J. (2021) Reptile Conservation: Global Evidence for the Effects of Interventions for reptiles. Conservation Evidence Series Synopsis. University of Cambridge, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

Reptile Conservation

This Action forms part of the Action Synopsis:

Reptile Conservation
Reptile Conservation

Reptile Conservation - Published 2021

Reptile synopsis

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 21

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 ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust