Smooth Green Snakes Reintroduced Into Wild

Six tiny, brightly colored juvenile smooth green snakes were released into the wild on June 30 at Old School Forest Preserve in Libertyville.

Half were “hard-released directly into the wild, while half were “soft-released” into pre-release enclosures within the preserve, where they will spend some time getting accustomed to being wild while contained in a controlled, managed environment designed to limit predators of the snake.

Over the course of the summer, about a dozen more snakes will be released – some will have very tiny radio transmitters affixed to them so the biologists are able to track their movements better and keep tabs on their survival success rates.

Rare Species

An exceptionally small insectivore, these snakes are difficult to spot in their grassland prairie habitat. They are also difficult to find because they have become so rare in Illinois. A collaborative conservation effort between Lincoln Park Zoo and Lake County Forest Preserves aims to boost their population numbers through scientific study, breeding, monitoring and reintroduction efforts. 

Lake County Forest Preserves wildlife biologist Gary Glowacki explained that for more than a decade, the district has purchased and/or restored a significant amount of lands containing suitable smooth green snake habitat.

“Despite this, the snake is still found only in a handful of isolated areas in Lake County that contain remnant grassland habitat,” he said. “The remaining populations may not be viable in the long-term due to small numbers and because habitat fragmentation, primarily due to roads and other physical barriers, makes re-colonization of restored sites improbable.”

According to the Illinois Comprehensive Wildlife Action Plan and Strategy, the smooth green snake is identified as a “species in greatest need of conservation.” Populations of this species are declining due to habitat loss, conversion of grasslands into agriculture, urbanization, and the widespread use of pesticides.

“Currently, Illinois only has less than 1 percent of its pre-settlement prairie acreage remaining, so species that depend on grasslands are in need of conservation,” said Lincoln Park Zoo reintroduction biologist Allison Sacerdote, Ph.D.

Partnership To Aid Snakes

With little chance of natural recovery, the Lake County Forest Preserves and the zoo partnered in 2010 to aid the recovery process through population supplementation, translocation, and reintroduction into suitable habitat.

The partnership’s first challenge was to locate the snakes last summer – not an easy proposition with such a small population of tiny snakes that blend in so well with the grasses. But hard work paid off when a few adult snakes were located and brought to the zoo for breeding, and a large communal nest of more than 80 smooth green snake eggs was discovered in an undesirable location that is slated for development. The eggs were taken to the zoo for incubation and 83 neonates hatched in midsummer 2010. 

The biologists and animal care staff at the zoo are breaking new ground with the care and study of this species. Very little is known about it as there are no published accounts of any other accredited zoo ever caring for this species, and there are very few scientific studies related to the species. As such, the team is employing a number of different rearing and reintroduction techniques for the neonates to determine which methods garner the highest success rate. 

“We hope that this recovery program will not only restore a more robust population of this species in Illinois, but our work may also be a model for other organizations and regions seeking to help this species recover,” Sacerdote said.

Information submitted by Lake County Forest Preserves District.