Day 5: Fuzzy, Fragile Superheroes … and How to Find Them in the Dark
It’s bat day, and today I was made aware that bats are indeed the only flying mammals we know of! Wannabe pilots like the Northern Flying Squirrel (Glaucomys sabrinus) don’t qualify, because heir flying attempts are not self-powered and therefore merely gliding maneuvers. Bats, however, are very energy sufficient flyers with a wing structure that can be - other than in birds - compared to fingers. This particular anatomical structure allows the bat to fly their skillful signature zigzag moves due to superior articulation of their wings. These furry, little aviators also make up for a total of 20% of the global mammal population and are therefore one of the most diverse groups of animals next to insects, with more than 1200 different species known to date. As a major pollinator and pest controller, bats contribute an average of $74 per acre per year in savings for farmers and, in addition, are integral for the ecological stability in the area they live. Bats can easily live up to 10+ years if they survive their first year.
In Ontario, Canada eight different types of bats can be found, and all of them are insect hunters:
The Hoary Bat (Aeorestes cinereus) is the biggest of the North American bats. Fun fact: these critters use their furry wing membrane as “slippers” to keep their feet warm when hanging around.
The Eastern Red Bat (Lasiurus borealis) is the only local bat that regularly has more than one - and up to five - little bat babies. Males and females are colored differently.
The Silver Haired Bat (Lasionycteris noctivagans) is the slowest flyer of all bats in North America.
The Big Brown Bat (Eptesicus fuscus) is a very common species that loves to roost and hibernate in attics.
All of these three bats migrate for the winter to spend some quality time in the warmer areas of the South, while the following five like it cold and hibernate in the North:
The Little Brown Bat (Myotis lucifugus) used to be the most common of the Northern American bats but unfortunately large parts fell victim to the so called White Nose Syndrom, a fungal infection that is rapidly affecting and devastating bat populations, resulting in declines of up to 98%. [X]
The Northern Long-eared Bat (Myotis septentrionalis) is a sleepyhead and hibernates up to nine (!) months. As the name suggest, this particular bat sports some nice, big ears. [X]
The Eastern Small-footed Bat (Myotis leibii) can be identified by their - wait for it - tiny feet. Who knew ...
Last but not least there the Tricolored Bat (Perimyotis subflavus), the earliest forager of all eight bats in the Northern realm. [X]
You probably noticed those bats marked with an [X]. Well, unfortunately these species are listed as endangered due to habitat decline, human intervention, and the contamination of caves and hibernation environments by the mentioned fungus.
Hunting while flying is of course a very specialized skillset. Bats use echolocation by means of ultrasound to spot their prey. These sounds are not on the spectrum for humans to hear as they range on a scale from 20 to 70kHz, while our own capability of hearing sounds is located somewhere around 16 kHz. Acting like a radar system, the echolocating technique creates a 3D image in the bat’s brain composed by receiving reflected sounds. If we could hear the same sound range bats create it would be way over 100 dB loud, which equals the noise of an annoying lawnmower. Now, this brings me right to our activity of today: we went on a trip to Makerspace North in Ottawa, run by Michael Grant of Krazatchu Design Systems, who mainly works with businesses and individuals to provide his services as an incubator space for innovation. Think about a creative studio environment that houses a wide range of enterprises from a gaming company to a robotics corporation and a solar energy business, CNC and laser cutting services but also a pretty cool, and well stocked, tool rental library. We gathered here to build a bat detector, a device that makes the otherwise inaudible bat sounds hearable, allowing the user to detect bats in the dark. Here are some process pictures of the built (device test report to follow) ...