The Bats Are Back!

A lesser long-nosed (left) and Mexican long-tongued bat vie for nectar

at one of our hummingbird feeders.

 August heralds the arrival of nectarivorous bats at our hummingbird feeders.  I first learned about these little midnight raiders three years ago, not long after we moved to Arizona.  Hummingbird feeders that were full of nectar when we went to bed at night were drained by morning.  We didn't think our hummingbirds were nocturnal but we were puzzled by the phenomenon.  We began to suspect bats, and sure enough, one night we patiently watched our feeders and saw several fast-flying, long-nosed mammals lapping up sugar water.  Ever since, I have loved and been charmed by these fascinating often misunderstood creatures.

Three nectar-feeding bats converge.

Growing up in Virginia, I'd seen many bats darting about the night sky feeding on insects.  I never knew that there were nectar-feeding bats.   The southwest is blessed to see visits from all three of the long-nosed nectar-feeding species found in the U.S.  Arizona supports two of these species:  the Mexican long-tongued (Choeronycteris mexicana) and the endangered lesser long-nosed (Leptonycteris curasoae yerbabuenae).  Both species barely enter our country from their home in Mexico.   Each is about three inches long, weighs less than an ounce, and displays wingspans between 13 and 16 inches.  The third species, the Mexican long-nosed bat (Leptonycteris nivalis), enters the U.S. from Mexico near the Big Bend National Park area.

A Lepto and Choero are held by a scientist doing research in my backyard.
You can see where the right bat has been marked with green on its head
so we would know we'd already sampled him if we caught him again. 
The scientists were very gentle with these docile animals. 
Regarding rabies--No!  For the most part, nectarivorous bats do not carry rabies.
In fact, a 2011 study by the University of Calgary
proved that less than 5% of bats carry rabies.  Less than 1/2 % of bats
that are tested show positve for rabies.

For the past two years, I have been submitting data about nectar-feeding bats to a Hummingbird Feeder Bat Study Program run by the town of Marana, AZ, in partnership with the city of Tucson, the University of Arizona, the U.S. Fish and Wildlife Service, the Arizona-Sonoran Desert Museum, Bat Conservation International, and the Arizona Game and Fish Department.  Citizen volunteers have been providing information to the study program since 2006.  Tucson and surrounding towns are using these data to develop habitat conservation plans and find ways to better protect these beneficial animals.  Scientists are using study information to locate unidentified roosting areas and to monitor migration corridors.




Both species have little flaps of skin protruding from their noses.
Scientists think this is used to fine-tune echolocation.

I recently read an article by the National Park Service that touts our nectar-feeding bats as "heroes of the night sky and Sonoran Desert.  These animals are critical to the propagation and survival of columnar cacti, including saguaro and organ pipe.  As cactus and agave flowers emerge, they emit a musky scent that draws bats to them.  The bats stick their long, narrow noses down into the flower and use their lengthy tongues to lap up sweet nectar.  Meanwhile, they are collecting pollen which they then transfer to the next flower and plant they visit.  After the cacti set fruit, the bats once again visit and feast on the sweet pulp.   The ingested undigestible seeds are deposited elsewhere after defecation. 



An adorable little lesser long-nosed bat.  It is sad that these animals are endangered.  They are critical to the Sonoran
Desert's circle of life.

Last year, the U.S. Fish and Wildlife Service and University of Arizona netted bats in my backyard to collect pollen samples from them that would tell the scientists what plants the bats were visiting.  This was when I discovered that BOTH species of Arizona's nectar-loving bats are frequenting our feeders.   The scientists netted six bats, two Leptos and four Choeros including some juveniles.  I was able to see these fascinating creatures up close, and even touched their wings, which felt like soft, sturdy sail cloth.

The comb-like feet are perfect for grooming.

This year, my first bats arrived on August 11.  There were at least three licking nectar from our feeders at 10:45 p.m.  Their arrival is a few days earlier than last year's, which occurred on August 14. 

I hope to get a few photos of this year's furry fliers and share them on my blog.  In the meantime, I'll be stocking up on sugar and making LOTS of nectar because these little pirates consume enormous amounts of nectar.  They don't leave until early October.  My hummers don't mind sharing, but they do want the feeders refilled promptly in the morning so that breakfast is waiting for them.