Guardians, Martin County looking for ways to reduce wildlife carnage on Bridge Road

A dead 7-foot alligator lying on the roadside and a roseate spoonbill twisted in an unnatural pose: gruesome indicators that Bridge Road between Hobe Sound and Interstate 95 is deadly for wildlife.

The Guardians of Martin County have documented 289 animals — including 11 alligators, 13 raccoons, 13 softshell turtles, 17 armadillos and 12 opossums — killed along the 6-mile stretch of Bridge Road between Jan. 6 and Sept. 17.

Now the group is working with officials at Martin County, which owns and maintains the road, also known as County Road 708, to reduce the carnage.

While doing preliminary work last year on a project called the Loxa-Lucie Headwaters Initiative to preserve land in the headwaters of the Loxahatchee and St. Lucie rivers, Guardians Executive Director Greg Braun began noticing an inordinate number of dead animals along Bridge Road.

More: Fish in Loxahatchee, St. Lucie rivers could be added to endangered list

So since the start of 2020, the group has been compiling data on dead animals — including species and GPS coordinates of the kill sites — found along the roadway in twice-weekly inspections.

They probably would have found more than 289 dead animals, but the count paused between Jan. 23 and March 16 at the onset of the COVID-19 pandemic.

Why the carnage?

Braun has several theories to explain why there are so many dead animals along that stretch of road.

Wetlands on both sides of the road are part of a corridor animals use to move from the protected public lands of Jonathan Dickinson State Park south of Hobe Sound and Atlantic Ridge Preserve State Park southwest of Stuart.

"Bridge Road crosses the corridor," Braun said, "and the animals are hit as they cross the road." 

Also, animals forage for food in the drainage ditches and swales on both sides of the road, he said, "and they're hit as they cross from one side to the other in search of food."

Many animals use culverts under the road to go from one side to the other, Braun said, but when the culverts fill with water in the rainy summer season, they have to cross the roadway.

"That's why the mortality numbers jump up during the summer," Braun said.

Braun doesn't blame speeding or careless drivers for the animal carnage. The speed limit on most of the stretch of Bridge Road is 45 mph but drops to 35 mph close to Hobe Sound and increases to 55 mph near the freeway.

"I don't think anyone wants to hit a wood stork or a raccoon or a roseate spoonbill," he said. "They sure don't want to hit the 7-foot alligator we found. Whoever hit that knew they had hit something."

The Guardians and Martin County officials came up with what Public Works Director Jim Gorton calls "a tiered approach" to protecting animals.

Warning signs

First, the county will install "Wildlife Crossing" warning signs along the road "wherever the Guardians tell us are the best spots," Gorton said.

"Signs are the least expensive solution but also the least effective," Braun said. "But they'd be a good way to start."

A possible next step would be installing lights to cut down on nighttime collisions.

"We're exploring the lighting option," Gorton said. "We've had requests to put lights out there before, but we've also had requests not to put in lights. They'd help protect nocturnal animals, but we're not sure if they'll be a huge benefit."

The "huge benefit" the Guardians are looking for: Enlarging the several culverts under the road at sites along the 6-mile stretch to accommodate wildlife as well as water.

That's easier said than done, according to Gorton.

More space, more water

Besides the nearly $900,000 to build the crossing, enlarging the culverts to include a dry path for land animals would also increase water flow and flood land downstream.

"We couldn't put the crossings in today because there's nowhere to put the water," Gorton said.

What Gorton calls "very, very preliminary plans" include a project that would help solve both wildlife carnage and flooding in Hobe Sound.

As part of the Loxa-Lucie Headwaters Initiative, the Guardians hope to buy land on the north side of Bridge Road just west of Hobe Sound. Gorton said the county hopes to get an easement for property on the south side all the way to Jonathan Dickinson State Park.

"The project isn't in our 5-year plan," Gorton said, "but there is a lot of interest in improving drainage in Hobe Sound. A project like this flow way would help do that, especially in the Hobe Heights area, which had such bad flooding this year."

More: Hobe sound families still in flooded homes after weeks of rain

The Guardians have collected enough money to pay for the study until October, Braun said, "but we'd really like to have a full year of data to reflect the changing water levels in the wet and dry seasons and what happens during the fall bird migration. The more data we collect, the better we can inform the decision makers."

Tax-deductible donations can be sent to: The Pegasus Foundation, P.O. Box 787, Hobe Sound, FL 33475

Road Kill Roundup

The 227 dead animals found from Jan. 1 to Sept. 17 along Bridge Road between Hobe Sound and Interstate 95 include: 

Alligators: 11

Raccoons: 13

Softshell turtles: 13

Anhingas: 4

Armadillos: 17

Opossums: 12

Black racer snakes: 23

Pig frogs: 42

Leopard frogs: 17

Snowy egrets: 2

One each: snowy egret, pygmy rattlesnake, diamondback rattlesnake, wood stork, roseate spoonbill, little blue heron, wild hog, osprey

Source: Guardians of Martin County

Tyler Treadway is an environment reporter who specializes in issues facing the Indian River Lagoon. Support his work on TCPalm.com.  Contact him at 772-221-4219 and tyler.treadway@tcpalm.com.