Blake Sasse, the non-game mammal program coordinator for the Arkansas Game and Fish Commission (AGFC), recently updated Commissioners at a regularly scheduled meeting on the status of white nose syndrome (WNS), a disease that is killing bats by the millions in the U.S.
“You hear about chronic wasting disease (CWD) with deer, and we’re all concerned with it, but I’m equally concerned about WNS in our bats,” Sasse stated. According to Sasse, the disease is actually a fungus that grows on the bats during hibernation and causes them to wake prematurely.
“Our bats are insect eaters, and they hibernate during winter because of the lack of insects at that time of year,” Sasse said. “Waking up raises their metabolism and causes them to burn fat reserves they’ve set aside for winter. They essentially starve to death as a result of coming out of hibernation early.”
Sasse went on to explain that the fungus is widespread in Europe and Asia, but bats in those regions have adapted to it over a period of time. Much like a number of other invasive species, the fungus has done an extreme amount of damage to bat populations in the U.S. since its arrival.
“Ninety-nine percent of northern long-eared bat populations have been killed because of this disease,” Sasse said. “They were once about as common as an opossum in New England. Now they are listed under the Federal Endangered Species Act.” Sasse did say some populations of little brown bats have seen a leveling off of the decline from WNS, but the damage to those populations had already been as high as 90 percent mortality before that occurred.
“We don’t know if those populations will have enough individuals left to recover,” Sasse said.
As insect-eaters, bats save the agricultural industry millions of dollars in insect damage each year as they remove some of the pests that plague certain crops. They also eat many other pests and insects that can be vectors for disease, such as mosquitoes.
Many forms of mosquito-borne disease either exist in Arkansas or have been introduced here in recent years. More disease could occur as a result of an increased mosquito population due to the decline in the numbers of bats, making protection of bats a high priority. Natural forms of disease control tend to be much less expensive when compared to medical costs to treat a disease.
The AGFC also said that during the past four weeks the agency had received reports of dead waterfowl at seven localized areas in northeast and east central Arkansas. Four of these incidents included white-fronted geese and a small number of dabbling ducks. Three other incidents have included mostly snow geese. Tests are still pending for some birds found dead, but test results from the first case indicated those birds died from avian cholera.
Dr. Jennifer Ballard, state wildlife veterinarian for AGFC, said the birds all showed signs of the disease, but confirmatory testing was needed to be certain of the cause.”
“Avian cholera is very common in waterfowl,” Ballard said. “Snow and Ross’s geese have been reported to act as silent carriers of the bacteria that causes it.”
According to Ballard, carriers can shed the bacteria into the environment, where it can wait in the water for weeks. In many cases, birds can die in a matter of hours after being exposed to the bacteria.
“Avian cholera isn’t new to Arkansas,” Ballard said. “The most recent large-scale event on record was in 2008, when close to 1,000 snow geese were found dead.”
The disease is not expected to have any population-level effects, but it can cause high rates of death in small areas, particularly when waterfowl densities are high. This year’s widespread drought conditions may be contributing factors in the most recent occurrences, concentrating geese in small areas with surface water.
The bacteria causing avian cholera can infect a wide range of species, including birds and mammals. It can infect humans but is not the same bacteria associated with human cholera that plagues many developing countries. Domestic livestock, such as chickens, are also susceptible to avian cholera.
The Arkansas Livestock and Poultry Commission and AGFC are coordinating on the issue. Arkansas State Veterinarian Dr. Brandon Doss considers the occurrence of avian cholera in wild ducks and geese to pose a minimal risk to the state’s poultry industry. However, poultry producers are encouraged to maintain good bio-security measures at their facilities at all times to prevent disease transmissions to and from wild birds.
The AGFC recommends any hunters who find animals that are dead, appear sick, or behave abnormally to contact the AGFC. Never consume any animal you know to be sick. Wear disposable gloves and wash your hands thoroughly if you handle sick ducks or geese.
In other game and fish news, the commission cautioned hunters, campers, and other outdoor enthusiasts to pay particular attention to the dry conditions now present around the state. Most counties in Arkansas are still under a burn ban, and it only takes a spark to start what could easily become an uncontrolled fire. Burn bans and warnings will stay in place until there is enough rain to alleviate drought conditions.