Bats! (Stuff I Compiled Teaching a Halloween Themed Science Camp)

  Bat Faces:

Bat Ears:

Bat Noses:

Bat Feeding Methods:

Some places they live:

Neat facts I learned (mostly from my science teacher mom, Lucy-Kate!):

• Bats are closer related to humans than they are mice/rats.
• 900 species worldwide
• Mexican free-tailed bats can migrate up to 1,300 miles
• Largest: flying fox--6 ft wing spam
• Smallest: bumblebee bat from Thailand--2 oz weight
• 70% of bat species are 'microbats'--typically insectovores
• 30% are megabats--typically frugivores
• Bat specialist Merlin "Batman" Tuttle has estimated that a single mouse-eared bat can catch up to 600 mosquitoes in just one hour
• Frog-hunting bats, found in tropics, can tell if a frog is poisonous or too big to ear just by listening to the frog's call
• Some bats echolocation is fine-tuned enough to "see" something the width of a human hair
• Often bear one pup a year
• Many fruit eating bats are -vital- for seed dispersal
• Bat echolocation often uses multiple frequencies--high pitched that goes straight out and a lower pitched tone that is more diffuse.  Based on the percent reflection the bats can pin point where the reflection is coming from.  
• Tree lures bats with specially shaped leaves that sound pretty.

Bats Are Helicopters and Birds Are Jets - Or, Why Birds Can't Echolocate

I, as well you should be too, am fascinated with the idea of senses outside of the human norm.  Ultraviolet, Infrared, electro-magnetic, lateral line, blood hound like sniffers, pit viper pits, and the quintessential example--echolocation are boggling to consider.  What does it 'look' like to them?  Can they hear in 'color'?  Are those potential 'colors' the same as our colors just applied differently?  What would it be like to experience that breadth and depth of perception!?!?!?!!

(Aside thought: Take dolphins for example.  They can detect a quarter sized object 100 feet away.  Furthermore, they can like Superman see through material and see a fish under the sand or hiding amongst weeds.  They can even tell if another dolphin is pregnant.  Geewillakers!  Eegad!)

Ever have this thought, though?  If bat echolocation is so awesome (And it is awesome.  There are more species of bats than all other mammals combined) why aren't there birds that can echolocate?  (Okay, there are some that can a little, like the chimney swift)  It certainly isn't for lack of vocalizations!  And, it isn't that they don't have great hearing, either!!!  Why then aren't there super owls that mega-death the bats out there?  Why are birds so gosh-darn restricted to be denizens of the day?!?  Let me hit you with something: birds have been around at least 3-4 times longer than bats.  Why the heck can't they echolocate?!!!

So, I had a thought.

Have you ever seen a bat fly?  They kind of look like big moths/butterflies flying.  They flap, flutter almost haphazardly.  Birds seem to flap more when they slow down to land, but bats flap less.  If I may stereotype, birds cruise and bats float.  The difference just might have something to do with the way their different wings evolved.

You remember this from school, right?  Plane wings are shaped like bird wings--the top is convex and causes lift. Once the bird gains enough speed the wing takes over, in a sense, and its shape causes flight.

Bats don't have that luxury, though.  Or, is that such a bad thing?...

Bats, like pterosaurs, don't have this Bernoulli effect going on as much.  They just have a thin membrane stretched between feet and digits.  This isn't all bad, though.  While bullet like speed is sacrificed, what is lost is more than gained in dexterity and agility.  This membrane isn't simply flappy skin.  It has muscles and, particularly in the case of bats, has finger structures that can modify the shape of the wing to enable dazzling maneuverability juking, hovering, and stopping on a proverbial dime.

So, birds are jets and bats are helicopters.  Birds slice the air.  Bats caress and churn the air.  To oversimplify: birds wing shape lifts them, while bats flapping provides their lift.

It just may be that birds can't hack flying in the dark because they just have to go too fast to be airborne.  Evolution is constrained to only work with what it's has or had.    If birds had wings with ruddering fingers and membranes then maybe they, too, could slowly go nocturnal and echolocative.  For now, though, bats rule the night!!!

Papa's Got Tatas - Male Lactation in Dayak Fruit Bat

Male mammals have nipples.  Some men get breast cancer and get mammograms.  Why don't they ever breast feed?  Well, there's one mammal that does!  It's the Dayak Fruit Bat of South East Asia.

City Lights Affect Species Evolution

The presence of city lights will affect a host of organism's evolution.  For millions of years nocturnal species have been adapting to see better, hide better, use the moon and stars as navigational points and now all that is changing.  Instead of the dim glow of the moon city and suburb dwelling species are blasted with the brightness of the mid-day's sun throughout the night.  How will they change?

I started to think about this as I frequently run at night (about to do ten miles after I finish this).  The sights are familiar to us all: swarms of insects pounding their little heads on the street lights bulbs--like a moth to a flame as the proverb goes.

It isn't just the insects that will be affect.  It is also their predators and migratory animals.  It's a common occurrence for me to see toads perched below street lights waiting for a morsel and I can easily see how a evolution could easily select for toads that like the street light's glow (perhaps their eyes will change, perhaps their behavior).  I see the same to be true with bats.  Any smart bat will quickly realize that under a street light is the place to be for a quick and easy meal.  There is one large bridge that I run underneath that this is especially true and based on sightings and chirps I hear I would imagine there to be several hundred bats within the area (modern day 'caves').

Due to light polution migratory birds are forced to travel 'blind' to the stars.  Many experiments have been in planetariums to show that birds do indeed orient themselves to various constellations.  If you turn the constellations in the planetarium, so do the birds turn the direction they fly and scratch in their cage.  With light pollution backscattering off the moisture, clouds and pollution of a city, how will migratory species deal in these visual orientation dead zones?  An increased ability to navigate by magnetic orientation?

What about circadian rhythms?  Another relatively frequent occurrence while I run is to hear birds chirping in trees near very brightly lit parking lots.  Surely this didn't happen before man.  Their brain is confused.  Is it day time or night time?  How will 24 hour light affect sleep patterns in animals?  Why stop there!  How will/does it affect us, humans, now!!!?

It might be helpful to think of the street light as today's watering hole.  Prey congregate there (not for water, due to an orientation short circuit, or possibly in the future to find a mate) and predators lurk in the dark waiting to pounce.

Questions that might be answered by experimentation: In a new housing development, would insects 'learn' to avoid bright lights at night to avoid getting eaten?  How have predators adapted to use this new 'watering hole'?  Are insects using lights as a meeting ground to mate?  Are circadian rhythms affected by street lights?  Are organism's eyes changing to deal with the new exposure (iris constriction) and/or spectrum used?  How are birds adapting to being 'blind' to the stars?

We all want to know what the future holds.  Go to any taro/palm reading/horoscope/end time prophecy section at the book store and it's abundantly clear.  What does the future hold for these night dwelling species?  How will they be affected by 24 hour lighting?  Just like the famous peppered moth near London that became darker due to predatory selective pressure to blend in with the soot from coal being burned, so will these species need to adjust their game plan to cope with a new pressure.