New Details Emerge on Mystery Bat-Killer Disease
For the first time, scientists have developed a detailed explanation of how white-nose syndrome is killing millions of bats in North America.
For the first time, scientists have explained in detail the way in which white-nose syndrome progresses as it kills bats.
A study by a team of researchers from the U.S. Geological Survey (USGS) and the University of Wisconsin wanted to test the hypothesis that white-nose syndrome kills bats by making them use more of their precious energy store than usual when they're hibernating.
They measured the amounts of energy used by infected vs. healthy bats in hibernation, as expressed by the bats' proportion of lean tissue to fat mass by the experiment's end. The results showed that bats infected with white-nose syndrome had higher lean-tissue-to-fat-mass ratios and were using twice as much energy during hibernation as were the healthy bats.
Worse still, the infected bats showed physiologic imbalances -- such as body-wide acidification and pH imbalances and high potassium levels -- that could hinder them in areas such as normal heart function.
Another key finding the researchers made was that visible changes in the bat, such as severe damage to the wings, were indicative of later stages of the disease.
"Clinical signs are not the start of the disease -- they likely reflect more advanced disease stages," said the study's lead author, University of Wisconsin and USGS National Wildlife Health Center scientist Michelle Verant.
Bat populations in North America have declined sharply in recent years, due to white-nose syndrome, which is caused by the fungus Pseudogymnoascus destructans. The fungus destroys the bat's skin in areas where there is no fur, such as its wing membranes, muzzle and ears.
The team writes that it has used its research to create a multi-stage model for how the disease progresses within bats, one that points to hypotheses that can be tested to gain a better understanding of white-nose syndrome.
"The mechanisms detailed in this model will be critical for properly timed and effective disease mitigation strategies," said Verant.
The team's findings have been published in the journal BMC Physiology.
Most of these little brown bats hibernating in a cave in New York State have white fungal growth on their muzzles, which is a common characteristic of white-nose syndrome.
Security officials have announced that bomb-sniffing dogs and counter-terrorism officers will be patrolling the stadium during the Super Bowl on Sunday in New Jersey. Even for regular games, MetLife Stadium informs visitors: "Vehicles are subject to search by New Jersey State Police, which could include a canine unit. Those ticket holders refusing a search of their vehicle will not be permitted to enter the SporSecurity Complex."
For the past nine years, firefighter Michael Marra at the Meadowlands Sports Complex -- home to MetLife Stadium -- has cared for feral cats on the property, according to The Humane Society of the United States. Marra has led the effort to help trap, spay, neuter and vaccinate the cats. Many of the felines have since been fostered and adopted.
Muskrats abound at the Meadowlands site, according to Erik Kiviat and colleague Kristi MacDonald of the non-profit environmental research institute Hudsonia. In a paper for the journal Urban Habitats, they write that muskrats, along with voles, mice, rats and rabbits, are important prey of predatory mammals, birds and snakes at the site.
Meadow jumping mice, common at Meadowlands, can leap a distance of 10-12 feet.
The Norway rat, a.k.a. common brown rat, loves stadium food leftovers. Officials have reduced the Norway rat population at the stadium by closing all but one of nearby garbage landfills.
More than 260 species of birds live in the restored wetlands adjacent to the stadium. Various types of sandpipers are among that avian group. Daily counts of sandpipers exceed more than 5,000 during most years, Kiviat and MacDonald report.
Kiviat and MacDonald write that "the Meadowlands are an important foraging area for herons from nesting colonies in other areas of the New York–New Jersey Harbor estuary complex." Herons might mate and nest in other parts of New Jersey, as well as nearby New York, but they associate Meadowlands with good eats.
Service dogs, such as those that assist the blind, are permitted at MetLife Stadium. The venue's Carry-In Policy says that animals, in general, are not permitted to be carried into MetLife Stadium "with the exception of a service animal."
There are 45 mammal species in northeastern New Jersey, according to the Urban Habitats report, and close to half of these live at Meadowlands. Bats, such as little brown bats, are among the resident mammals. The Federal Aviation Administration has called for a temporary flight restriction over MetLife Stadium on Super Bowl Sunday. So human aircraft won't be in the airspace over the stadium, but bats and birds not deterred by the crowds might fly by to check things out.
As football goers shiver in the stadium, think of nearby minks. Though rare, these sleek mammals with natural fur coats have been spotted near the stadium. Minks snack a lot when they are bored, according to researcher Rebecca Meagher of the University of Guelph. The furry animals might then also come to mind as TV viewers nosh on more than their usual amount of chips, sliders and beer.