Stay in the know about wildlife, water quality, and ecosystems on Sanibel and Captiva Islands and in Southwest Florida

What’s a False Crawl?

June 24, 2024
sea turtle false crawl tracks

If you’ve ever walked the beach in the morning and discovered a set of sea turtle tracks in the sand, only to return later to find no nest area staked off or any trace of a sea turtle’s presence at all, you may have encountered a non-nesting emergence, or “false crawl.”

false crawl tracks sea turtle

A false crawl is when a female sea turtle comes ashore but does not lay eggs. This is a common occurrence — with hundreds to thousands of false crawls documented per season on Sanibel and Captiva — but the frequency at which false crawls occur varies from year to year. 

So far in 2024, there have been 1,142 false crawls on the islands. In 2023, there were over 3,400 false crawls over the entire season, while in 2022, there were only around 1,000.

“It’s not always understood why a sea turtle false crawls,” said SCCF Sea Turtle Biologist Jack Brzoza. “It can happen naturally, likely a result of the beach conditions, or be caused by some external disturbance, such as artificial lighting, human presence, or some other physical disruption.”

Some studies have looked at why turtles “choose” to lay their eggs in some areas over others, and it’s possible false crawls may happen if certain cues are missing to signal a suitable nesting site, such as sand moisture content, slope, elevation, or wave exposure.

Types of False Crawls
false crawl tracks on beach
Loggerhead false crawl tracks

There can be several different types of false crawls, categorized by how much nesting effort the turtle displays. A turtle might barely come up onto the beach at all before turning around, or she might begin the nesting process all the way up to digging a partial egg chamber before ultimately false crawling.

“An egg chamber might have been abandoned on a false crawl because the turtle encountered thick roots, debris, loose dry sand that caves in, or some other deterrent that inhibited digging. However, sometimes, there’s nothing obvious the turtle encountered while digging that would cause her to abandon the nesting attempt,” Brzoza said. “Generally speaking, when an adult female sea turtle comes onto the beach, there is a strong biological drive to lay eggs, so if she does false crawl, she will return to the beach to successfully nest within the next day or two.”

Data from SCCF’s nighttime sea turtle tagging research project, which has run May through July since 2016, have supported this. 

“From tag information that identifies individual turtles, we have seen turtles false crawl multiple times before successfully nesting later that night or within a few nights later,” Brzoza said.

So the next time you find yourself wondering why a set of sea turtle tracks leading from the ocean up the beach and back does not end in a nest protected by yellow stakes, you may be looking at a site where a turtle considered laying her eggs, but in the end performed a false crawl.


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