What happens when you bring together researchers and conservationists from the U.S. and Mexico for six days in the Sierra Madre Oriental mountains of Nuevo Leon? You get an amazing, collaborative effort to save the endangered Mexican long-nosed bat (Leptonycteris nivalis)! I joined colleagues from Especies, Sociedad y Habitat A.C., Instituto Tecnológico de Ciudad Victoria, Universidad Nacional Autónoma de Mexico, Bat Conservation International, New Mexico State University, and Texas A&M for a six-day PIT tag training workshop in the Parque Nacional Cumbres de Monterrey. We gathered near an important roosting cave for the Mexican long-nosed bat, Infierno Cave, where the females gather every summer to give birth to their pups (babies).
The goal of our workshop was to train everyone on how to
insert and use PIT tags in bats, and to tag Mexican long-nosed bats that we
caught emerging from the cave. So what are PIT tags? PIT stands for Passive
Integrated Transponder. PIT tags are basically like the chips that we put in
our pets to help us identify a lost animal. The tags are small and rod-shaped,
and are inserted under the skin on the back of the bat. Whenever a tagged bat
flies past a PIT tag reader (installed in the caves or handheld), the time,
date, location, etc. are recorded. Currently, we have a system of PIT tag
readers installed at several important roosting caves for the Mexican
long-nosed bat, in central Mexico and the U.S. Southwest. By tagging bats here
in the northeast of Mexico, we can track where these bats migrate through, and
when. This information is important to help us understand where to target
conservation efforts and to understand future threats that the bats may face as
the timing of flowering of their food plants (such as agaves) shifts with changes
in climate.
We arrived at the cave on Sunday evening and set up camp in
the area of the cave. We used that first night to set up my infrared cameras at
the cave entrance (which is a giant sinkhole in the ground) to watch where
exactly the bats emerge and determine where to set up our mist nets. We saw
that they fly out of the cave in all directions, but preferred several paths
through openings in the trees. The next night we set up seven mist nets all
around the cave entrance to catch as many bats as possible.
Having a good chat after setting up camp.
Outside the cave entrance.
The infrared cameras set up outside the cave entrance,
ready to watch the bats as they exit.
Checking all the mist nets for holes.
The line of mist nets at the cave entrance.
Once we caught a bat in the mist net (which is like a giant
hair net with fine threads that the bats have trouble “seeing” with their
echolocation), we carefully untangled them and put them into their own “bat bag”
(a cloth bag with a drawstring). We caught numerous bats throughout the night,
and created a line of bat bags on a clothesline. One by one we processed the
bats. This entails measuring the length of the bat’s forearm, weighing the bat,
determining the sex, age, and reproductive status (e.g. if it’s a female, it
could be pregnant, lactating, post-lactating, or non-reproductive). Then came
the PIT tagging!
Dr. Jose Juan Flores Maldonado and Ana Gabriela
Casteneda Aguilera taking a bat out of the net.
Holding a Mexican long-nosed bat, my study species.
Another Mexican long-nosed bat.
A line of "bat bags" full of bats waiting to be processed.
The bat processing table, where all the action happens.
Dr. Emma Gomez-Ruiz measuring the forearm length of a bat.
Dr. Gomez-Ruiz weighing a bat.
Doing the PIT tagging was a bit nerve-wracking, but I
managed to successfully tag three bats. You basically use a little “gun” (kind
of like a hot glue gun) with the rod-shaped tag inserted into the tip of a needle.
You then pull up the skin on the back of the bat (like scruffing a dog or cat)
and insert the needle under the skin. You then eject the tag and pull the
needle out. Finally, you put a dab of surgical glue on the entry point to make
sure the tag stays in. Each tag has a unique number ID so we will always be able to identify each individual bat we tag. Then we release the bat!
Scanning the PIT tag to make sure I have the correct number.
Wetting down the fur around the area where I will insert the needle.
Inserting the needle with the tag under the skin.
The needle inserted under the skin.
Putting a dab of glue on the entry point.
Successful insertion!
A Mexican long-nosed bat (Leptonycteris nivalis)
L. nivalis
On two days we opened the nets back up in the early morning
(from 4:30am to 6:00am) to catch the bats coming back into the cave after a
night of foraging on agave nectar. We caught some Mexican long-nosed bats with
yellow agave pollen on their faces and wings!
You can see the yellow agave pollen on the bat's face.
And there is also pollen under the wings!
Another shot of the Mexican long-nosed bat.
A great experience for me was catching a Mexican
long-tongued bat (Choeronycteris mexicana), which also feeds on agave nectar and
pollinates the plants. In the photo below is a Choeronycteris mexicana (on the
left) and a Leptonycteris nivalis (on the right). You can see how much longer
the nose is on the Choeronycteris. I also set up my infrared cameras one night
at a nearby flowering agave and saw these guys feeding on the agave nectar.
Below is a slow-motion video, in which you can see their long nose:
A Mexican long-tongued bat (Choeronycteris
mexicana). Notice how long its nose is!
The wing of a Mexican long-tongued bat.
A Mexican long-tongued bat (Choeronycteris mexicana) on the left,
and a Mexican long-nosed bat (Leptonycteris nivalis) on the right.
A Mexican long-tongued bat (Choeronycteris mexicana) feeding from an agave.
We also caught other species besides Mexican long-nosed
bats. We caught several new species for me, including my first Vampire bat
(Desmodus rotundus), which was SUPER neat to see! Its belly was fat with its
blood dinner. We also caught a Pallid bat (Antrozous
pallidus), which I’ve seen flying around agave flowers at night (see my
previous blog post, “The Many Faces of Agave Visitors"). Finally, we caught a Townsend’s big-eared bat
(Corynorhinus townsendii), which has GIANT ears!
Vampire bat (Desmodus rotundus)
Pallid bat (Antrozous pallidus)
Townsend's big-eared bat (Corynorhinus townsendii)
We spent our days having good discussions about the
conservation of the Mexican long-nosed bat across its range, hiking around and
exploring the nearby area, and catching up on field stories. It was an amazing
six days, and I’m really looking forward to seeing the data we get from the PIT
tag tracking across Mexico and the U.S. Southwest. I’m also really looking
forward to continuing this bi-national collaboration to help conserve the
endangered Mexican long-nosed bat!
Discussing the range map of the Mexican long-nosed bat.
Emma and me with our Disney hats on!
You couldn't ask for better scenery!
Our collaborative group from the U.S. and Mexico, working
to conserve the endangered Mexican long-nosed bat!
Wow! It reminds me of our nights in Texas - no PIT tagging of course - but I remember the mist nets, bat bags, and processing :) One question...when did you sleep?! Mist netting/tagging at night and chatting/hiking during the day...I remember that about Texas, too! ;)
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