Big Fish: Return of the Alligator Gar

Alligator gar are back at Spunky Bottoms. (Left to right) Researcher Nathan Grider of Univeristy of Illinois-Springfield, Doug Carney of Illinois Dept of Natural Resources, Nerissa Michaelsof the Illinois Natural History Survey and Tharran Hobson of The Nature Conservancy.

Alligator gar are back at Spunky Bottoms. (Left to right) Nathan Grider of University of Illinois-Springfield, Doug Carney of Illinois Dept of Natural Resources, Nerissa Michaelsof the Illinois Natural History Survey and Tharran Hobson of The Nature Conservancy.

by Matt Miller, senior science writer

Once they were the river’s top predator: a fish that could reach ten feet or more, with thick armored plates as scales and imposing jagged teeth.

You would see their long, tooth snouts poking out from the river’s surface, gulping air—their adaptation for thriving in warm, deoxygenated water.

Alligator gar.

They thrived in a large swath of mid-western and southern waters, but by the early 1900s, they were already starting to disappear, a trend that continues to this day.

They were declared extinct in Illinois in 1994. But a new restoration and research effort aims to bring back these incredible fish, and help conservationists at other rivers and waters better protect them.

When fisheries biologists Rod Hilsabeck and Trent Thomas of the Illinois Department of Natural Resources decided to return the alligator gar to their state, they knew they needed a perfect location. The Nature Conservancy’s Spunky Bottoms Preserve fit everything they sought.

Formerly farmland, Spunky Bottoms is now 2000 acres of restored wetlands and uplands. It consisted of perfect gar habitat: backwaters and sluggish pools with lots of vegetation. It also was not connected to the adjacent Illinois River, making it easier for researchers to capture and study the fish.

Research is a key component to the reintroduction. Nathan Grider, a master’s student in biology at the University of Illinois-Springfield, is working with Dr. Michael Lemke and partners to study two key aspects of gar restoration.

They are studying how fast gar will grow when restocked into an area. They are also analyzing their diet, and in particular, if the gar will eat (and control) the non-native carp that swim Spunky Bottoms and so many other waters.

This information will help inform gar reintroduction and protection efforts throughout their range.

Gar Wars

Alligator  gar caught at Moon Lake, Mississippi. March 1910

Alligator gar caught at Moon Lake, Mississippi. March 1910


For much of the last century, gar were not protected; they were persecuted. People called them “river pirates.” It was not intended as a compliment.

They accused gar of eating game fish. They accused them of eating humans. (Jeremy Wade, host of the often-sensational River Monsters, could find no evidence this has ever happened).

Facts aside, even fisheries managers in the early part of the 20th century wanted to eliminate alligator gar. They encouraged people to net them, shoot them, dynamite them. Gar died by the thousands.

This relentless persecution, coupled with dams and the loss of backwater habitats, led to a decline and loss of alligator gar across their range. Slow to mature and slow to reproduce, alligator gar cannot sustain heavy mortality; they’re now considered at risk of extinction.

Today, conservationists, anglers and naturalists have found a new and growing appreciation for the fish: a gar renaissance, if you will.

“The attitude towards gar is changing,” says researcher Nathan Grider. “People recognize that the fish are important to the river as a top predator. When even popular game fish like largemouth bass and crappies become too abundant, they get stunted. Predation from gar can keep that from happening. Their presence makes the fishery, and the river, healthier.”

Grider notes that the fossil record for alligator gar in North America goes back more than 3.5 million years, and other gar species swam the waters more than 135 million years ago.

“They literally swam with the dinosaurs,” he says. “They are an ancient lineage that has changed little evolutionarily.”

This new gar appreciation is perhaps best typified by the wonderfully exuberant book by Mark Spitzer, Season of the Gar, a celebration of “the coolest fish that lives.”

“More than any other fish, gar are prepared to fight on, adapt away, and crawl from the muck again,” Spitzer writes.

But they may need some human assistance. Research like that conducted at Spunky Bottoms will play an important role.

The Gar Returns

Researchers sample the stomach contents of an alligator gar. Nathan Grider photo

Researchers sample the stomach contents of an alligator gar. Nathan Grider photo


Spunky Bottoms was stocked with 22-inch-long alligator gar from hatcheries two years ago. Last year, Nathan Grider and his team began capturing them (primarily by netting), measuring them and recording their diets.

Could restocked gar thrive in a restored wetland? Oh yeah. In fact, fish gained as much as 14 pounds in just 17 months.

“It was impressive growth,” says Grider. “We knew the exact age of individual fish, because they came from hatcheries. The fish at Spunky Bottoms grew faster than gar in any reintroduced population.”

That was in large part due to an abundant food supply. The gar ate almost entirely gizzard shad, a small forage fish. As the gar grow, researchers hope they also begin chomping down carp.

“They can certainly get big enough to eat carp,” says Grider. “Further research will help determine if there is a possibility to manage invasive species by reintroducing a top predator into the habitat.”

And what about the alligator gar’s fearsome reputation? Grider and fellow researchers handled a lot of the toothy fish. They also used a technique called lavage, in which the gar’s stomach is pumped with water to flush out its food (the gar is not harmed).

“Lavage is certainly not a pleasant technique, so you might expect the gar would react violently,” says Grider. “That wasn’t the case. You have to respect them. They have the equipment to inflict damage. But none of us were bitten or hurt during our research efforts. Despite the myths and legends, alligator gar are actually pretty docile creatures.”

This is part of an ongoing series on Conservancy fisheries research and how that work intersects with some of the biggest, wildest fish in freshwater.

Nathan Grider and Ron Hilsabeck hoist "the coolest fish that swims."

Nathan Grider and Ron Hilsabeck hoist “the coolest fish that swims.”

Opinions expressed on Cool Green Science and in any corresponding comments are the personal opinions of the original authors and do not necessarily reflect the views of The Nature Conservancy.

Posted In: Fish, Science

Matt Miller is a senior science writer for the Conservancy. He writes features and blogs about the conservation research being conducted by the Conservancy’s 550 scientists. Matt previously worked for nearly 11 years as director of communications for the Conservancy’s Idaho program. He has served on the national board of directors of the Outdoor Writers Association of America, and has published widely on conservation, nature and outdoor sports. He has held two Coda fellowships, assisting conservation programs in Colombia and Micronesia. An avid naturalist and outdoorsman, Matt has traveled the world in search of wildlife and stories.

Comments: Big Fish: Return of the Alligator Gar

  •  Comment from Dale Frank

    I am curious to see their impact on nesting waterfowl, specifically ducklings. As most of us know, small bodies of sheet water with adjacent upland cover is prime nesting habitat for ducks and geese. The last thing they need is an additional predator. What are Your thoughts?

  •  Comment from Nathan Grider

    Hi Dale,

    While there have been few published studies on alligator gar, most of them have been on diet due to the concerns of sportfish consumption. Most literature agrees that feeding behavior is “opportunistic,” meaning they will eat whatever prey ventures close enough. The most abundant prey-sized fish in the environment is typically what is found in the stomach. There have been a few mentions of birds in their stomachs. In 1942, E. C. Raney published “Alligator Gar feeds upon Birds in Texas,” in Copeia. He explained that alligator gar caught by angling (not during research) contained large birds in their stomachs. He also told a story of someone witnessing a water turkey (Anhinga anhinga) being eaten and ducks once shot by hunters. Again, these are just stories and not well documented. I am not aware of any waterfowl/birds found in stomachs during scientific research, except for one chicken (used as bait) that likely came from a crab line. Fish seem to be their prey of choice. However, they may eat waterfowl on occasion and given the opportunity. Given the alligator gars small numbers throughout their range, they are probably not a significant source of predation on nesting waterfowl.

  •  Comment from Olaf

    I’m a big fan of gar, both as a fisherman and a lover of interesting animals. The idea that there could again be alligator gar right here in Illinois is very exciting. This is a story I will be following closely. Maybe some day I’ll be able to take my daughters fishing (catch and release, of course) for gator gar in their home state!
    Keep up the good work.

  •  Comment from Marcia

    Pretty! This was an incredibly wonderful post. Thank you for
    supplying these details.

  •  Comment from kiara

    ie been studing ths creaturefor three onths no d its really interresting

  •  Comment from Robert Black

    Nice article. I never knew of those fish until I moved to S. Florida in 1980. The fish are common in Everglades National Park, but I never knew they could get as big as the monster pictured in B&W in the article. Neither did I know the fish were endangered in any way. I guess it shows you can learn some thing new every day. Those fish sure would chomp on Asian carp, as well as snakeheads and almost any other fish they could catch.

    •  Comment from Bob Faber

      I don’t think the gars in south Florida are alligator gars. I think their historic range was inland along the central Gulf coast and up the Mississippi Embayment.

  •  Comment from Don Smith

    Will the fisheries biologists Rod Hilsabeck/Trent Thomas or the Illinois Department of Natural Resources be providing the spunky Bottoms Alligator Gar Study finding’s to the U.S. EPA Great Lakes Advisory Board. This could be pivotal in the development of the new Great Lakes Restoration Initiative (GLRI) Action Plan who’s current main focus is the Asian Carp threat to the Great Lakes.

    The growth rates are promising for Northern Water’s.

    •  Comment from brandon schanke

      I think it was pretty interesting reading about these phenomenal creatures of the wet lands. It’s pretty unique how we first went after them to saving them if we made them extinct the food changed would be very screwed up.

  •  Comment from Alex Renbarger

    It would be interesting to see if the Gar would survive the cold Michigan waters. Lake Michigan is being overrun with Asian Carp. It will soon begin to affect sport fishing and economical impact.

  •  Comment from Brettny lovers

    I wonder if they live up here in acworth ga

  •  Comment from Chuck

    A pound of prevention..using the Asian carp problem as an example, the federal government must take a more aggressive approach to prohibit the importation, legal and otherwise, of foreign species. Think of the dollars and effort being put forth trying to solve a problem that was caused by fish farms importing the fish to be used for the only purpose of cleaning the ponds. Then there is the giant snake problem in the Everglades and the Emerald Ash Borer due to poor oversight by the importing companies…Vigilence must be increased and given a higher priority.

  •  Comment from Dwayne

    This week I caught the prettiest fish in my 65 year old age life. An small alligator gar with a white belly dark green body with spiral markings on its tail. Wish I’d taken a picture before I released it back in the Meramec River near St. Louis.

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