Surveying Our Bug-Eating Backyard Buddies – the Bats!
With the sun set and the mostly full moon hidden behind the trees outside Brevard, North Carolina, a cluster of biologists and volunteers conducted their final preparations under the light of their headlamps. The time was near. I was handed an N95 mask to allow me to get close while keeping the animals we were evaluating safe. As twilight consumed us, we entered the time of the bats.
Bats are small, fast, flying mammals. Their nighttime activities, unique appearance and mysterious nature has given them a negative rap that clings to them like Halloween cobwebs. In reality, bats are ecologically significant animals that keep insects in line and pollinate! Though they prefer to stay hidden from humans, their nighttime escapades should not go unnoticed. One bat alone can eat thousands of insects in a single night!
Unfortunately, the story for bats is not all soaring through the sky and munching on delicious bugs. The hibernating bat population in North America has taken a severe hit. In 2006 white-nose syndrome (WNS) was discovered in a cave in New York and since it has spread to thirty-eight states. This fungal disease is easily passed between bats and disrupts their hibernation, causes their metabolism to spike and depletes their fat stores, often starving them to death. The fungus can also eat away at the bats’ bodies, so if starvation doesn’t kill them the secondary infections will. To put the significance of WNS in perspective, since it first appeared multiple bat species’ populations have decreased by 90 percent.
In addition to WNS, bat populations in the U.S. are also impacted by anthropogenic factors like habitat fragmentation and climate change. With most bats only giving birth to one or two pups a year, the outlook is not good for these tiny backyard exterminators. This is where our gathering of scientists and volunteers comes into play. Capturing, evaluating and documenting bats in areas we know they frequent can help shed a little light on how various species are doing.
The biologists I was with in North Carolina set up three mist nets along the nearby river and every eight minutes they checked the nets to see if any bats had been bagged. It was slow going at first, but by 10pm the nets started bringing in the bats. We caught several Eastern red bats, one tricolored bat and a few gray bats during this four-hour survey.
Once the biologists have captured a bat, they begin examining the individual. They start by weighing the bats in a small net bag. Then, they gently remove the bat from the bag with gloved hands and measure their body and check for parasites. While they are taking these measurements, the biologists are also able to determine the bat’s sex and whether they are reproductively active.
The final measurement is of the bat’s wing, which is the bat’s forearm and hand. The biologists will gently stretch out and shine a light on the wing, illuminating it like a leathery lampshade. If the wing’s bones have not completely fused together and the cartilage allows light to pass through, then the bat is considered a juvenile. If the light is occluded by the fused bone, it’s an adult bat.
Lastly, the biologists band the bat with a specially designed, lightweight tag that crimps around the lower arm bone. Now that all the measurements are complete and everything is recorded, the bat is released back into the wild.
There are many ways to aid our bat population. Protecting surviving populations from human-caused threats under the Endangered Species Act, scientists have more time to save bats from WNS. Defenders played a key role in the advocacy and litigation that led to the listing of several species under the ESA. Defenders also works to protect bat habitats on National Forests and seeks proactive conservation measures to maintain and connect vital habitats.
You, too, can help these awesome creatures. One of the easiest ways is to advocate and speak up for bats. Educate your friends and family on the importance of having these mammals in our backyards and neighborhoods. You can also take things a step further and install a quality bat house in your yard! Whenever you are exploring caves, make sure you decontaminate yourself and gear before entering. Finally, if—like bats—you enjoy being out at night and have a sense of adventure, you can volunteer with Defenders next summer to conduct more bat surveys! Simply email us at firstname.lastname@example.org for more information.
This blog was written by our Southeast Field Conservation summer Intern, Tory Ash.