Rodent control methods negatively impact non-target species

October 12, 2023

The von Arx Wildlife Hospital is located and part of the Conservancy of the Southwest Florida in Naples, FL. Call 239-262-2273 for wildlife assistance. We are open 365 days a year from 8am to 7pm.

A burrowing owl and a raccoon were among the 75 animals admitted to the von Arx Wildlife Hospital at the Conservancy of Southwest Florida this past week. Other admissions include a wild turkey, a loggerhead shrike, two brown thrashers, a little brown bat and two Florida softshell turtles.

Burrowing Owl Caught on Rodent Glue Trap

The burrowing owl was found on Marco Island stuck to a sticky glue board rodent trap. Per a conversation with the rescuer, it was suspected the burrowing owl could have been stuck to the trap for an extended period of time due to the amount of feces surrounding the glue trap.

A burrowing owl is admitted to the von Arx Wildlife Hospital after being found stuck to a glue board rodent trap. Glue traps are inhumane and often injure and kill non-target species of wildlife.

The owl was significantly underweight, which reinforced the suspicion that it had been stuck to the trap for several days. The owl was struggling against the adhesive, had an increased respiratory effort and rate and had damaged feathers on its wings and tail. Hospital staff administered pain medication and a sedative to calm the owl.

A natural soy based solvent was used to remove the adhesive from the owl’s feathers and legs followed by a bath with Dawn dishwashing detergent to remove the soy solvent from the owl’s feathers.

The owl was placed on supplemental oxygen in a heated animal intensive care unit to rest and dry off. After several hours, electrolytes were given along with additional pain medication. The following morning the owl was standing, both wings were in proper position and the owl had eaten its rodent diet. The owl was moved to a larger recovery enclosure in the bird room. Handling was minimized in order to reduce the stress on the owl.

Glue traps are an inhumane method of rodent control and should not be used. No animal deserves to die slowly of starvation and dehydration. 

Solutions for controlling rodent populations must focus on removal of the cause.

  • Eliminate food sources
  • Securely close trashcans
  • Remove thick vegetation near your home
  • Never feed pets outside
  • Seal any holes that may allow rodents entry into your home
  • Hire a reputable pest control company to create a pest-management plan that includes protecting the health of local wildlife. 

Preventative measures and exclusion lead to long-term solutions.

The burrowing owl was not the only animal who suffered from rodent control tactics this past week.

Raccoon Ingests Rat Poison

A nuisance wildlife trapper arrived at the von Arx Wildlife Hospital with a juvenile raccoon cowering in the corner of a live trap. The trapper was working on Marco Island and found the young raccoon with her head stuck in a black box rat bait station with green rodent poison in her mouth and on her muzzle. Knowing that rat bait is deadly, he contained the raccoon in the live trap and brought her to the von Arx Wildlife Hospital to be treated for rodenticide poisoning.

The raccoon had already ingested the rat poison by the time she arrived at the wildlife hospital. The label on the rat bait box indicated the poison was a second generation anticoagulant. Staff administered subcutaneous electrolytes and Vitamin K – a critical component in the production of blood clotting factors in the liver. Staff settled the raccoon in an ICU enclosure to rest. 

The raccoon was monitored closely over the following days.

While she didn’t shown signs of internal bleeding, Vitamin K must be given for a minimum of thirty days to combat the effects of the second generation anticoagulant rodenticide.

Vitamin K has become standard with all admissions where anticoagulant rodenticide poison is suspected. Rodenticide poisoning admissions are now occurring on a weekly basis, often with multiple patients each week suspected of having second generation anticoagulant rodenticide poisoning. 

Second generation anticoagulant rodenticides (SGARs) are compounds that inhibit normal blood clotting resulting in excessive bleeding and death. The poison bait kills rodents, but can also cause mortality in non-target species of mammals and birds either through primary exposure (eat the poison bait), as was the case with the young raccoon, or secondary exposure (eat a poisoned animal). 

Used to eliminate rodents from homes and businesses, black box rodent bait stations are everywhere. The indiscriminant use of second-generation anticoagulant rodenticides means the environment is flooded with poisons that are killing the very species (owls, hawks, eagles, foxes, bobcats, opossums) that are nature’s pest control.

Rodent control is a difficult issue with no quick and easy solutions, but the case of the young raccoon highlights the effect anticoagulant rodenticides have on non-target species.

Preventative measures, such as storing pet food or birdseed in sealed containers and exclusion from homes, garages and other structures are long-term solutions to rodent issues that don’t compromise environmental health. Some communities are enacting stronger restrictions regarding the use of rodenticides to protect wildlife as the dangers of SGARs and the ramifications they have on native wildlife are revealed. More needs to be done. Stay informed and support laws that protect native wildlife.

Recent Releases

A little brown bat, seven Brazilian free-tailed bats, an ovenbird, a marsh rabbit, a little blue heron, a red-eyed vireo, three eastern cottontails, four mourning doves and four grey squirrels were released this past week.

Special Thanks

Von Arx Wildlife Hospital staff thanks Chris Stephens, owner of Natives of Corkscrew Nursery in Ft. Myers, for provided discounted services and plants to help the Conservancy in our continued efforts to restore gopher tortoise habitat destroyed by floodwaters from Hurricane Ian.

The plants were delivered on Thursday. Early Sunday morning a small group of FGCU students met wildlife hospital and spent several hours planting three hundred plants. Everyone’s involvement in this project is appreciated and will have a direct benefit on the tortoise population. Thank you all!

FGCU helps with the Smith Preserve on our campus

Opportunities to Help

Visit the Conservancy website to view all of the amazing volunteer opportunities at the Conservancy of Southwest Florida.

Volunteers help in many different capacities and are vital to the work we accomplish saving injured, sick and orphaned wildlife. Please, we desperately need volunteer help. If you could dedicate one shift a week to help at the wildlife hospital, contact our volunteer office and get involved.

Currently we need volunteer help with our outside morning shift and our evening shift.

Your volunteer time, donations, and memberships are vital and allow us continue our work to protect Southwest Florida’s water, land, wildlife and future.

Joanna Fitzgerald is director of the von Arx Wildlife Hospital at the Conservancy of Southwest Florida, 1495 Smith Preserve Way, Naples, Florida 34102. Call 239-262-2273 or see conservancy.org.