Bats offer far more insect control than danger.
Photo courtesy Vikram Misra
Professor is batty over furry fliers
Published 11:05 PDT, Wed October 30, 2019
Last Updated: 1:33 PDT, Thu October 31, 2019
Vikram Misra loves bats.
The virus specialist first got into bat diseases to be closer to his wife.
While working at the University of Saskatchewan, he became eligible for a study year away. Misra has a joint appointment at the U of S College of Medicine and at the Western Veterinary College, the vet school for the four western Canadian provinces.
“I wanted to do (my study year) in Winnipeg. My wife had a job there. I thought it would be nice to spend a year with her.”
With this summer’s Metro Vancouver rabies death seemingly due to contact with a bat, interest in both rabies and bats is heightened. Richmond’s many old farm buildings provide rich bat roosting territory.
According to Danielle Dagenais of the BC Bat Community Program, many of Richmond’s bat haunts are unknown. She warns people to keep an eye out for them and report locations of roosts. There are good maps for many communities but, unfortunately, not for Richmond.
While bats are mainly beneficial to humans due to their insect control and pollination, they can carry diseases both overseas and here at home. Until Misra did his research, it was unclear what infections Canadian bats did carry.
Misra, knowing the risks and wanting to work in Winnipeg, thought at the time: “Hey, there are lots of bats in Canada. We don’t know about viruses in them.”
Virus specialist Misra wrote to the head of Canada’s National Microbiology Laboratory in Winnipeg, requesting a year-long position there to study viruses in bats.
Misra lists the diseases that he says “spilled over from bats to humans”:
-Severe Acute Respiratory Syndrome (SARS) that in 2003 claimed 44 lives in Canada
-Middle Eastern respiratory syndrome (MERS)
-Marburg, a hemorrhagic and often lethal virus
-Hendra that infects Australian horses and has recently killed four people, including a vet.
“Even Ebola very likely passed from bats to horses to people,” Misra says.
Nipah virus is also transmitted from bats to people. Nipah causes a brain inflammation that is usually fatal in humans, Misra says: “It is an issue in Malaysia and now an issue in Bangladesh and India, again transmitted from bats to people.”
The National Microbiology Lab’s director said he’d always wanted to study the transmission of viruses from bats to humans in Canada but didn’t have the personnel. “Come on along,” he told Misra.
Misra, who earned his PhD at the University of British Columbia in microbiology, says we need to respect wild animals rather than fearing them. He says we should leave them alone, but not work to eradicate them. For Misra, that’s doubly true for bats.
Misra says, “In the wild, rabies is relatively rare in bats.”
He notes that in bats found lying on the ground—whether alive, in distress, or dead—rabies is more common. “For bats behaving abnormally, the percentage with rabies is quite high. In the bats submitted to labs, because people found them on the ground, the Canadian wildlife health people say 10 to 13 per cent have rabies.”
To be safe, if you find a bat on the ground, Misra says: “Just leave them alone.”
There are rabies vaccines that work on humans and animals. In fact, some countries will not allow an animal across their border without proof of vaccination. Some regions of Canada put out bait laced with vaccine if rabies is spreading in wild animals.
If you are in a profession where you are likely to be exposed, especially those who work with animals and wildlife, consider getting the rabies shots.
“For example, most of the veterinary students that come through here get vaccinated against rabies. I’ve been vaccinated,” Misra says.
But should the general public get their shots, just in case? According to Misra, “No, the general public should not be running out to get the rabies vaccine.”
The one big exception is if you think you may have been exposed to rabies. You need to tell your primary care physician or go to emergency as soon as possible.
When started on time, a series of injections prevents your getting the fatal disease. Once rabies symptoms show up, it is untreatable. All doctors can do is make you comfortable, as was the case with the young man from Vancouver Island who died. He didn’t suspect rabies until the lethal symptoms showed up.
In addition to getting yourself into medical care right after you suspect contact with a rabid animal, Misra says, “As soon as possible, if you’ve had contact you’ve been bitten by an animal, if it is at all possible, capture it or bring it in.” Testing the animal takes a few days to see if it is rabid or not.
Misra says the post exposure rabies shots are no longer painful: “Our vaccines are much better now. All those horror stories are not true anymore.”
Once again, with bats, Misra stresses respect is crucial.
“The important thing is people should leave bats alone.”
He says bats behaving oddly, like flying during the day or flopping around, can be a sign of illness.
“On the other hand, we should do everything we can to help bat conservation with such things as proper bat houses.”
Misra’s fondness for the furry creatures of the night is obvious. “Bats are addictive once you realize how amazing they are. Oh, they are very cute. I don’t know why people are afraid of them.”
He says bats are both widespread and diverse. Some have a six-foot (1.8 metre) wingspan while others, like the bumblebee bat, can fit on the end of your thumb. The majority of bats are small and light, weighing about the same as a male hamster.
One fifth of all mammal species are bats. Within those 1,500 different species, Misra says, “They occupy just about every ecological niche, including the far North, except the Arctic and Antarctic regions.”
He says each bat has evolved to do a certain environmental job. In fact, he says, “We’d have no tequila without the specialized bats that pollinate the blue agave used to make the liquor.”
Bats are our friends, says Misra. They eat a mass of insects—including mosquitoes—every day, as well as preventing diseases these insects’ bites could transmit to humans.
It’s not just tropical diseases like malaria that you can get from mosquitoes
Misra has lists of nasty diseases Canadians can get from insect bites, such as West Nile virus, Rocky Mountain spotted fever, three kinds of encephalitis (brain inflammation), and Lyme disease.
So, even in Canada, mosquitoes can cause much more than just an itchy bite.
Bats actually prevent far more human disease than they cause. They have not been blamed for any of the 24 rabies deaths in Canada over the past 100 years. The risk is low: since 1924, there have only been two rabies deaths in BC.
In summer, when people often travel to other provinces to camp, it is worth noting that a variety of wild animals can be rabid throughout Canada. The main offenders are raccoons, bats, skunks, and foxes. But rabies has also been found in beavers, black bears, field mice, groundhogs, hares, mink, muskrats, otters, rabbits, weasels, white-tailed deer and wild boars in Canada.
Through nurturing these little insect-eaters in our neighbourhoods, we keep ourselves and our pets healthier by preventing insect-borne diseases. These can be very serious, life-changing infections in humans, pets, and livestock.
West Nile virus first came to prominence in 2002 when exceedingly ill people were showing up at emergency wards. At first, it was thought to only cause a severe neurological illness. However, when stored blood samples from other patients with similar milder neurological symptoms were tested, those patients also had West Nile virus. This mosquito-spread disease was much more widespread that originally thought; at first, only life-altering cases were blamed on West Nile.
It’s a virus normally found in birds who are later bitten by mosquitoes. The mosquitoes catch it and transmit it to the humans they bite.
Bats help prevent West Nile virus by eating vast amounts of the insects who spread it. Our local bats actually have special enzymes in their stomachs to help them digest insects.
According to the Mayo Clinic, “Signs and symptoms of West Nile fever usually last a few days, but signs and symptoms of (brain inflammation) can linger for weeks or months. Certain neurological effects, such as muscle weakness, can be permanent.”
And that’s not the only severe infection these flying mammals can prevent. The United States researched Western equine encephalitis, another transmitted brain infection, as a potential biological weapon before suspending the program. By eating potentially infectious mosquitoes, bats can also help control the spread of this virus.
Bats also act as overall insect repellents. Because some bugs can hear these flying predators nearby, insects tend to avoid yards with bats.
If you find bats living with you and want them gone what do you do?
Misra says, “We need to be sure we don’t kick them out of our attics when they are most susceptible. If you want them out of your attic, probably later in summer is best because, if you have a maternal colony with pups in May or June, you don’t want to disturb them.”
In fact, according to Dagenais, it is illegal to get rid of bats or to shut them into or out of their home during certain times of the year.
She says, “According to the BC Wildlife Act, from May 1 to Sept. 1, you cannot exclude bats during that time. The reason is, if you exclude the females, then the pups will die.” For more information on what’s legal and what is effective go to https://www2.gov.bc.ca/gov/content/environment/pesticides-pest-management/managing-pests/animals/bats
Misra also suggests not persuading bats to move on your own. “It’s probably best done with guidance of someone who knows what they are doing so (the bats) don’t get killed.”
Dagenais’ group offers guidance and pamphlets on how to safely deal with bats. Their website bcbats.ca offers many options. This active society also seeks the public’s help in finding bat roosts.
To contact Dagenais directly email her at Vancouver@bcbats.ca
“We don’t know where the bats are in Richmond. There’s a ton of bats in Delta and I assume there are a lot in Richmond.”
Dagenais asks that people who are outside at dusk or dawn watch for bats leaving or returning to their roosts, then report the sightings on BC Bats’ website.
And, unlike common myths, bats are not blind. They can see you. In fact, they can probably see better in dim light than you can—so stand still and let them avoid you.
Dagenais also cautions that in the summer, unscreened windows or doors should not be left open overnight.
“The pups grow up in about six weeks so it’s a pretty steep learning curve.” The adolescent bats don’t know not to go into houses yet, she says.
“We (at BC Bats) do a lot of outreach and education. I am a bat biologist. I love them. I’ve been working with them for 8 years now.”
Every spring, Dagenais offers a workshop at the Richmond Nature House about the benefits of living around bats.
In Dagenais’ master thesis research, she found that Okanagan vineyards with high bat populations had a greatly reduced need to spray pesticides on their growing grapes.
In fact, she encourages the people of Richmond to contact the South Coast Bat Conservation Society to purchase a bat house for their yard or complex. They cost about $80, far less than electric insect repellants, and bat houses cost nothing once installed.
“You can stick them up on post on the side of the house or an outbuilding or put them on a snag or a telephone pole or a tree,” Dagenais says, stressing that bat houses have to be in fairly specific places within a yard. Check with the conservation society to see if your place is suitable.
A bat colony can have as few as 20 bats, but they can eat hundreds of thousands of mosquitoes each night.
Climate change makes bats even more important
With climate change comes an even greater need to control mosquitoes naturally. The ever-vigilant bats, who rely on the blood sucking insects for food, are indiscriminant.
The Canadian Public Health Association sounds the warning for the formerly tropical strain of mosquito that carries dengue virus, Zika virus, yellow fever, and chikungunya virus. They say: “(This kind of mosquito) is currently found as far north as the northeastern US, with the northern edge of its range being limited by winter temperature. Climate change could lead to the northward expansion of this species into Canada.”
The association warns this could lead to Canadians catching these nasty viruses that cause fever, rash, and malaise, as well as the possibility of paralytic Guillain-Barre syndrome. Pregnant women who catch Zika can pass along permanent brain damage to their babies.
And, Misra repeats, unless you have been vaccinated against rabies and trained on how to handle bats safely, don’t touch wild animals.
We still have much to learn about these nocturnal bug-eaters. Having started as someone interested in the immune system and microbiology—bugs that make us sick—Misra is now looking at why bats don’t get age-related illnesses like humans. They can fight infections without the inflammation or fevers humans get.
Bats’ heart rates can reach a healthy 1,000 beats per minute. A healthy human resting heart rate is about 60.
“We found one bat we had banded long ago. It was 30 years old and still healthy. Usually the smaller the mammal, the shorter the life.” Hamsters, the same size as many of our bats, usually live between two and three years.
Misra heads to Thailand soon for a conference on bats. “Once you start working on bats, you can’t stop,” he says with a warm smile.
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