Hard to believe, but October is already here! And that can only mean one thing — bats! Everyday throughout the month of October, follow CWF on social media and our blog to fly high with these incredible creatures of the night! Each day we will have fun facts, quizzes, and beautiful photos highlighting these amazing animals and the work CWF does to protect them.
Last week we gave an overview of bats in New Jersey with a news article written by CWF Wildlife Biologist MacKenzie Hall. Today we discuss some threats bats face today. Later this month we will debunk myths about bats, and share ways you can help!
Make sure to follow us everyday on Facebook and Twitter and read our blog every Friday for our #31daysofbats!
by Stephanie Feigin
Despite the many environmental and economic benefits bats provide, bat populations around the world are still declining. Bats face many threats today, including habitat loss and destruction, human persecution, disturbance of hibernating bats in caves and mines, wind energy development, and White-nose syndrome.
Human activity and persecution are among the biggest factors in bat population declines worldwide. The forests bats use to roost and forage in have been destroyed at an alarming rate for timber, new farm land, cattle pastures, or housing developments. In the last 50 years 17% of the forests in the Amazon have been destroyed and converted to cattle pastures. Bats are also being driven out of their roosts in caves or mines due to careless tourism. Today, the most important caves and mines are now gated to keep tourists out and protect the bats from any human disturbance.
In winter, large numbers of bats gather to hibernate in the relative warmth of caves and mines. The bats go through incredible metabolic changes during hibernation. Their heart rate slows from 1,200 beats per minute (in flight) to just 15-20 beats per minute, and their body temperature drops roughly in half to match the temperature underground. A little brown bat in torpor can actually go 48 minutes without taking a breath!
By slowing down, bats are able to conserve energy during the long winter without food. But they’re very vulnerable during hibernation – a single arousal can cost a bat 2 weeks worth of fat reserves. Too many disturbances can jeopardize their survival. Since bats reproduce slowly, usually only giving birth to one pup a year, disturbance to maternity roosts can also be very harmful to bat populations and it takes a long time for these populations to recover.
Bats have been misunderstood by humans for many years, and are still among the most persecuted animals on earth. In many parts of the world, bats are killed due to fear or harmful myths making bats seem scary or even dangerous. In Central America there have been numerous accounts of people destroying caves with the use of dynamite in attempts to kill vampire bats. However, many fruit-eating bats are also killed in the process by people who mistake them for vampire bats. Reportedly, 40,000 caves in Venezuela have been destroyed, resulting in the loss of large populations of other bats as well as other cave fauna. In Australia, flying foxes, primarily the Grey Headed and Spectacled flying foxes, are shot by farmers to keep the bats from eating their fruit trees — even though there are more effective alternatives. Both the Grey-headed flying fox and Spectacled flying fox populations have declined by at least 95% in the past century. In certain locations, bats are also hunted for food or folk medicines.
Wind energy development poses a growing threat to bats. As wind farms crop up along the ridgeline corridors used by migratory bats, the number of bat fatalities grows. Hundreds of thousands of bats are killed each year in the United States from collisions with the spinning blades of wind turbines or because of rapid pressure change at turbines which can rupture their blood vessels. In the east, studies have found that an average of 46 bats are killed annually per wind turbine. Fortunately, research is showing that bat deaths can be tremendously reduced by simply shutting the turbines down during seasonal low-wind periods, when power generation is minimal anyway.
Perhaps the most significant cause of declining bat populations in our region is a disease called White-nose syndrome that continues to spread across the United States and Canada. White-nose syndrome was first discovered in upstate New York in 2006, and has since spread to 25 states and 5 Canadian provinces, killing over 6 million bats in the process.
The disease is caused by a cold-loving fungus called Pseudogymnoascus destructans or Pd. It attacks hibernating bats, disturbing them during hibernation when the bats’ immune response is low, and preventing them from conserving enough stored energy to survive until spring. White-nose syndrome also causes dehydration and unrest as well as severe wing damage that can prevent bats from flying. At some sites, the mortality rates are 100 percent. Much is still unknown about White-nose syndrome, its spread, and its consequences. The federal government, states, several universities, and organizations like ours are working hard to track and understand this disease.
Though bats face many threats today, Conserve Wildlife Foundation continues to protect these incredible animals and educate the public about ways that you can help. Bats need our help!
Stephanie Feigin is a Wildlife Ecologist for the Conserve Wildlife Foundation of New Jersey
