Vehicles Driving Over Marked Nests — Risks Identified in 12,975 Sea Turtle Records

What actually happens when sea turtle nesting grounds and off-road vehicles share the same beach? A study revisiting 24 years of records from Cape Hatteras National Seashore in North Carolina reported a frequent occurrence that differed from the commonly cited issue of hatchlings getting lost in tire tracks: vehicles driving directly over nests that had been marked and fenced off.

However, this study did not experimentally measure the extent to which vehicle traffic reduced nesting success rates. It is an observational study that categorized interactions identified within approximately 13,000 field records compiled by the National Park Service and citizen science groups. Therefore, the figure of ’66 cases’ should be interpreted as the number of incidents that could be traced through records, rather than the upper limit of total damage.

30-Second Summary

• A total of 66 vehicle-sea turtle interactions were identified from approximately 12,975 nesting records at Cape Hatteras between 1999 and 2023.
• Vehicles drove over marked nests in 62.1% of cases, while 22.7% involved the relocation of nests from high-traffic areas.
• “83% of the recorded incidents occurred between June and July and were spatially concentrated around Cape Point.
• Since 2012, the recorded rate per 100 nests has been below 0.7, though the statistical design does not allow for a definitive conclusion that regulations are the cause of this decline.

What happened?

A research team led by Samantha Farquhar Frontiers in Ecology and Evolution published a paper on September 4, 2026, analyzing the intersection of beach vehicle traffic and sea turtle nesting activity at Cape Hatteras. Although the paper has a correction history dated September 9, the core data and conclusions remain unchanged. The study area covered 99.8 km of ocean-facing beach, patrolled daily during nesting season by National Park Service staff and trained N.E.S.T. volunteers.

Interpreting 24 years of field notes across six categories

The raw data consists of records entered into standardized spreadsheets by the National Park Service (NPS) and N.E.S.T. between 1999 and 2023. The data collected included information on egg-laying, signs of false nesting, species, coordinates, and field notes. By analyzing the content of these notes, the research team identified six types of incidents: ① vehicles passing over marked nests, ② nest relocation due to high traffic, ③ disturbance of nesting individuals by headlights, ④ direct vehicle collisions, ⑤ disorientation of mothers caused by tire tracks, and ⑥ disorientation of hatchlings. Frequency and distribution patterns—categorized by month, year, and species—were analyzed using SPSS 27, while spatial distribution was mapped using ArcGIS Pro; additionally, incident rates per 100 nests were calculated to account for annual variations in the number of nests.

Out of 66 incidents, 62.1% (approx. 41 cases) involved vehicles passing over the nest, 22.7% (15 cases) involved relocation, and 6.1% (approx. 4 cases) involved disturbance by headlights. The remaining cases involved vehicle collisions and disorientation indicated by tire tracks near mothers or hatchlings. By month, the distribution was 47% in June, 36% in July, 15.5% in August, and 1.5% in May. This period coincides with the peak of loggerhead sea turtle nesting and the peak tourist season.

The number of nests increased tenfold, while the recorded incident rate decreased.

The annual number of nests increased approximately tenfold, rising from 92 in 1999 to 937 in 2019. In contrast, the recorded rate of vehicle interactions per 100 nests was 3.5–18.6 cases between 1999 and 2002; it fell below 0.7 after 2012 and below 0.35 after 2018. The overall rate declined following a series of measures: temporary measures in 2008, regulations on permits and designated routes in 2012, and revisions in 2016. However, the paper does not conclude that the regulations *caused* the decline. This is because there is no model that simultaneously accounts for variables such as vehicle traffic, enforcement efforts, beach closures, patrol intensity, and habitat conditions, and also because the significant increase in the total number of nests (the denominator) played a role. The most reasonable interpretation is simply that there is an association—specifically, that the recording rate dropped following the implementation of management measures.

However, the paper does not conclude that the regulations *caused* the decline. This is because there is no model that simultaneously accounts for variables such as vehicle traffic, enforcement efforts, beach closures, patrol intensity, and habitat conditions, and also because the significant increase in the total number of nests (the denominator) played a role. The most reasonable interpretation is simply that there is an association—specifically, that the recording rate dropped following the implementation of management measures.

Why is this important?

Incidents were not evenly distributed along the coast but were concentrated at Cape Point, east of Hatteras Inlet, and north of Avon. This provides a rationale for focusing signage, education, enforcement, and traffic management on the specific locations and months where nesting activity and vehicle use overlap, rather than applying the same rules uniformly across all sections. Although loggerhead sea turtles accounted for 94% of the incidents, they also represented 94–97% of all nests, implying that this species is not inherently more vulnerable to vehicles.

Points to avoid overinterpreting

• Daytime patrols are effective at spotting tire tracks or damaged fencing but often miss nighttime disturbances caused by headlights or hatchling disorientation.
• The data represent a secondary analysis of field notes rather than an experiment designed specifically to assess vehicle impacts.
• Variations in the number of volunteers, patrol coverage, and recording methods may influence the annual incident counts.
• The figure of 66 incidents does not represent the total volume of damage or the overall reduction in hatching success.

Key takeaways for readers

• The most frequently recorded issue was vehicles driving over marked nests.
• Risks were concentrated in June and July and around Cape Point.
• Long-term citizen science records are valuable for identifying patterns in rare events.
• A decrease in recorded incidents cannot be definitively attributed to the causal effect of regulations.

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Original source, DOI, and references

• Farquhar et al. (2026), Frontiers in Ecology and Evolution, DOI 10.3389/fevo.2026.1928946
• Open-access journal article
• US National Park Service Cape Hatteras permit information