In 1998, Sanibel officially became an American crocodile (Crocodylus acutus) refuge that endorses a breeding population. Yet, no nests have successfully hatched — or possibly even contained fertilized eggs on the island since then.

Several hurricanes and 27 years later, courting behavior was captured on camera in February and the FWC is now monitoring the potential nesting of an island female. Will there be baby crocs?

Prior to courting behavior photos being shared with SCCF and the City this week, wildlife officials thought there were only female crocodiles on the island. The photos don’t confirm the presence of a male — only a physical exam could do that — but they do lead to speculation.

“The three significant storm surge events that occurred over the last two and a half years have transformed most waterbodies on Sanibel to a more crocodile-friendly habitat consisting of brackish water,” said SCCF Wildlife & Habitat Management Director Chris Lechowicz. “As a result, they move more freely around the island and use other water bodies. It’s also not implausible to have additional crocodiles begin using the island.”

The Back Story

American crocodiles (Crocodylus acutus) are one of two native crocodilians in the United States. As opposed to the American alligator (Alligator mississippiensis) that lives in freshwater, the American crocodile is primarily a brackish/saltwater species, that lives in coastal areas.

Most of their range is in coastal Central America, as well as the northern coast of South America, the west coast of Mexico, and most of the Caribbean islands. However, the northern extent of their range is in the Florida Keys and coastal south Florida on the east and west coasts. They have been documented as far north as St. Petersburg on the west coast and near Melbourne on the east coast.

The City of Sanibel passed the crocodile refuge resolution about three years after “Wilma” was routinely nesting in a yard adjacent to the J.N. “Ding” Darling National Wildlife Refuge.

“That crocodile, known by locals as Wilma, would nest mostly in a resident’s yard each year, but the eggs never hatched, either because of no nearby male interactions and/or cooler temps than further south that prevented the eggs from hatching,” said Lechowicz.

Successful reproduction had only occurred south of U.S. 41 in Collier and Monroe Counties on the west coast. However, in 2020, the first successful nests were documented north of that line at Rookery Bay National Estuarine Research Reserve in Naples. Two nests hatched, producing 16 hatchlings.

Crocodiles are limited by temperature, as seen from the mass die-off in 2010 from an extended cold spell, including the famous Sanibel crocodile that was first documented on the island in 1979. Wilma’s body was found by long-time SCCF wildlife educator Dee Serage-Century on the banks of the Sanibel Slough.

More than 200 people attended a memorial at SCCF to mourn her passing.

Since 2010, two known female crocodiles were relocated to Sanibel as part of the crocodile refuge plan.

Becoming a Crocodile Refuge

Establishing the island as a crocodile refuge came about in 1998 as part of the City’s sanctuary island ethic. It was also inspired by Wilma’s nearly two decades of living on the island.

The resolution states that Sanibel had the three elements most closely associated with reproductive success for the American crocodile: the right habitat, a suitable climate (lacking hard freezes), and access to fresh water (provided by the island’s unusual freshwater lens).

“Just as important, there is perhaps no community in the United States more strongly identified with an ethic of ecological preservation and restoration,” it adds.

A breeding population of American crocodiles on Sanibel would also “serve as a potent and popular symbol of Florida’s unique and priceless legacy of wildlife, highlighting the need for coastal habitat preservation and far-sighted ecological planning as Lee, Collier, and Charlotte Counties experience some of the fastest rates of urban growth in the country.”

The City also cites research showing that American crocodiles are significantly less aggressive than American alligators, which are more common on Sanibel.

FWC Monitoring Current Nest

One of the current female crocodiles has shown nesting activity this month by scratching or digging around a resident’s backyard adjacent to SCCF’s Wildlife Corridor, which lies between Casa Ybel Road and Tarpon Bay Road. WATCH WINK-TV story.

“At this time, it is unknown if she has nested yet or is simply still looking for the appropriate habitat to deposit and guard her eggs,” said Lechowicz.

City of Sanibel Department of Natural Resources Director Holly Milbrandt, who is working with the FWC on monitoring the nest, says it’s also unknown if there is a new male crocodile on the island or not.

“I feel pretty comfortable that we have at least three individuals that are spending some time on Sanibel, but they are not captives here and may come and go freely,” she said.

She also says it’s too soon to say whether or not the presumed nest will produce offspring.

“FWC’s crocodile response agent has been on site a few times but has been unable to investigate the nest to determine if eggs are present and/or if they are viable because the crocodile is present and guarding,” said Milbrandt. 

Courting Crocs?

Island resident Gary Biltgen — an avid wildlife photographer, golfer, and SCCF volunteer — started photographing two crocodiles together at the Sanibel Island Golf Club in February. These sightings marked the first time two crocs were documented together on the island since Hurricane Ian. 

Some of the photos he got and the activity he observed suggest that mating may have taken place, and a male may now live on the island.

“They were exhibiting courting behavior in a couple of ways.  First was ‘snouting’ — one actually puts their snout on the other. The other was blowing bubbles,” he said. 

The City has shared his photos with the FWC, which describes crocodile mating on its website as follows:

Male crocodiles begin courting females in late January and early February. Courting rituals can be extensive, often lasting for days. Males initiate courting by quickly and consecutively performing head slaps, and the female will raise her snout and arch her tail if she is interested. The last courting ritual involves the male and female rubbing snouts and submerging under water. 

SCCF will continue to work with partners at the City to provide updates on the potential nest.

Some interesting facts from FWC

Resurgence of Florida crocs

The Florida population of the American crocodile is a conservation success story. Listed as an endangered species in 1975, crocodile numbers have since recovered from a few hundred individuals to as many as 2,000 adult crocodiles today. The Florida population of this native species is now classified as threatened by the U.S. Fish and Wildlife Service.

How to tell a crocodile from an alligator

Crocodile

• Grayish green color
• Fourth tooth on lower jaw exposed when mouth is closed
• Narrow tapered snout
• Young are light with dark stripes

Alligator

• Black in color
• Only upper teeth exposed when mouth is closed
• Broad rounded snout
• Young are dark with yellow stripes

What a wide open mouth means

Crocodiles can be seen sunning with their mouths open, or “gaping.” This behavior is related to regulating their body temperature and does not mean that the crocodile is acting aggressively toward people.

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