Last Night’s Central Texas Bat Activity – 19 Feb 2018
Big Flights from Fern and Stuart out west

18 Feb 2018
Free-tails continue to move back in to the Bracketville radar area
overall numbers increasing between Fern, Stuart, and Frio Caves
uptick in San Antonio and at Congress


16 Feb 2018 (see below) First big flight (over 1 million) from Bracken since 20Nov2018
They moved back in a few nights ago from wintering in North San Antonio


14Feb 2018 (see below) – Frio has their first flight since before Christmas!
We think these are migratory free-tails that had started moving back into Fern & Stuart ten days ago but just now came back to Frio now that the weather warmed.

04 Feb 2018 (video below)
West Texas was heating up with huge flights from Fern, Stuart, and D’Hanis for the first time since late Nov early Dec~600k in N San Antonio but only ~27k at Bracken
~560k at Stuart – starting to heat up
~800k at Fern – first big all year since Dec 5th
~800k at D’Hanis – first big one since mid Nov early Dec
~140k McNeil
~75 Old Tunnel

Since 2011, we have compiled data nightly covering the Significant Bat Area of Central Texas.

Radar observations play an important role in the emerging, transdisciplinary field of Aeroecology and NOAA’s National Mosaic of 150 NEXRAD radar installations provides a treasure trove of data for population monitoring and studies of phenology, migration, and aerial behavior of “bioscatter” such as birds, insects, and bats.

Radar observations play a key role in keeping our finger on the pulse of Congress Avenue Bridge bat colony.  Follow the link for the latest Congress Avenue Bridge emergence data, fueled by our radar observations.

Nightly observances lead to interesting hypotheses that require more time and financial support to fully investigate, and volunteers are welcome to express interest on our volunteer page.  It could be anything from funding studies to data entry to boots-on-the-ground investigation of previously unknown roosts.

The Multi-Radar Multi-Sensor public website is a joint initiative between the National Severe Storms Lab, the Federal Aviation Administration, the National Weather Service, and the University of Oklahoma Cooperative Institute in Mesoscale Meterological Studies.  The MRMS is a mosaic of national NEXRAD radar installations and sensors.

We have used the MRMS site to track Central Texas bat emergences every night for the last six years (2012-2017).
In August of 2017 a new public MRMS Operational Product Viewer was finally rolled out after the old MRMS was brought in-house on March 1, 2017. We lament the six month hole in our data, but are glad to resume monitoring of bat emergences in the Central Texas Significant Bat Area.


Here are some old video highlights gleaned from our archives.

Video below: Congress Ave Bridge bats Fall Migration – Halloween 2014

Video below: Bracken Rules the Roosts: 19Jun2016 UTC
Now that the mega maternity colonies of Mexican free-tailed bats have mostly given birth to their pups, emergences are strong again all across Central Texas in the Significant Bat Area of the Hill Country. Pups are not yet flying!  Bracken Cave, of course, rules the roosts, as usual.


Video below: Frio & Bracken bats cover at least 40 miles in an hour in this video.  Mexican free-tailed bats are capable of flying over twice that fast in unassisted flight.  The location of both caves at the edge of the Texas Hill Country (dark grey at top) gives the bats immediate access to the agricultural fields that attract their favorite food, the corn ear-worm moth.
Could be as many as ~8 million at Bracken and ~6 at Frio, and this is just a snapshot in time, not the whole emergence!
Stuart bat cave and then Rucker emerge later at top left of video.

Video below: Skies Over The Edwards Plateau, from 2009.

Video below: Bracken Cave Fourth of July Farm Aid from 2013.

Video below: Frio & Wind Farm.  What looks like about 3-1/2 million bats (WAG) emerged from Frio Bat Cave and headed south toward the Winter Garden area south of Uvalde, providing free pest-control service to farmers in a large area west toward Bracketville.  Hope they stayed clear of the turbines at the wind farm.

The Old  Multi-Radar-Multi-Sensor site was brought in-house by NOAA on Feb 28, 2017.  The public site had not been well supported since Oct 2016.  Jian Ziang of the NSSL and OU School of Meteorology said the limited data (on a legacy page) was very spotty because “The legacy website was accessible to the public because it was hosted on a university domain, and we don’t have the funding to continue to support that anymore.”  For a while, starting Jan 2017 the legacy page had become more reliable but with just a few months of data available.  We are glad to have archived the previous five years of data before that occurred!

As of the end of 2017, we never were granted permission to use the new, in-house MRMS site, to be able to resume our ongoing five -year study of nightly emergences in the Central Texas Significant Bat Area (CenTex SBA).
The long-promised security clearance and log-in credentials for the new site never materialized, lots of broken promises by NOAA. Instead we are using their public-facing Operational Product Viewer, which has only a 1 week archive, instead of the multiple year archive of the old site.  Big disappointment of the use of our taxpayer dollars. We will continue to lobby for access to the new site.