Population census and GPS tracking data for Mexican long-nosed bats (Leptonycteris nivalis) in Texas
Data files
Jul 24, 2025 version files 216.14 KB
Abstract
The two files contain data associated with a final project report and Master of Science thesis on foraging behavior and population trends of endangered Mexican long nosed bats (Leptonycteris nivalis) funded by the Texas Comptroller of Public Accounts Natural Resources Program. These cave emergence data were collected from review of thermal infrared video of bat emergence and summarize the colony size between 2008 to 2024 at Emory Cave in Big Bend National Park, Texas. Separate census data are provided for Mexican long-nosed bats and other species found in the cave in the summer. The location data (coordinates collected by Lotek PinPoint GPS tags) for 21 bats was used to analyze foraging and movement behavior and are provided in a second document. These data were collected in summer of 2024 and have been adjusted by removing selected coordinates within a buffered region near the roost of approximately 1 km.
Dataset DOI: 10.5061/dryad.stqjq2cfg
Description of the data and file structure
Bat census was performed by manually counting bats in a replay of a thermal video file of the bats leaving their roost. Data are in the Emergence Counts file.
GPS location data were from Lotek Pinpoint GPS tags placed on Mexican long-nosed bats and programmed to take a fix every 10 min between sunset and sunrise. These data were used to estimate core ranges, movements, and foraging behavior.
Files and variables
File: Emergence_Counts_at_Emory_Cave__TX__USA__2008_to_2024.xlsx
Emergence counts of bats from Emory Cave, Texas, between 2008 – 2024 (these data were used for publication in Journal of North American Bat Research, have been submitted to North American Bat Monitoring Program for Grid Cell GRTS ID 109135, and were part of a final grant report to Texas Comptroller of Public Accounts Natural Resource Program)
Headings listed here are described in detail in the Excel sheet. NABAT format was used, and some headings did not apply to our data. These cells are blank.
File: GPS_data_Leptonycteris_nivalis__Summer_2024_GPS__TX__USA.xlsx
GPS coordinates and tracking data for 21 L. nivalis tagged in 2024 (these data are reported in a Master’s thesis by Flor Calderon and were part of a final grant report to Texas Comptroller of Public Accounts Natural Resource Program)
The following headings for this file (below) are in the Excel sheet. All GPS points that were >20 HDOP were excluded from data set. All GPS points within 1 km of Emory Peak, Big Bend National Park, TX were excluded from data set to protect the location of this roost site.
| Heading | Description |
|---|---|
| Index | Numerical identifier for this particular table |
| Tag ID | 5-digit numerical identifier given to each GPS tag provided by Lotek, Inc. |
| Fix Date-Time (UTC-5) | Date and time combined and converted UTC to local time (CDT = UTC - 5) |
| Longitude | Decimal degrees, WGS 84 |
| Latitude | Decimal degrees, WGS 84 |
| Altitude (m) | Height above ellipsoid (meters), WGS 84 |
| Satelites Used | Number of satellites used during fix |
| Deltas | Estimated horizontal error |
| HDOP | Horizontal Dilution of Precision. A lower HDOP value generally indicates better GPS accuracy, meaning the position calculation is less affected by factors like satellite geometry and signal interference. |
| eRes | Lotek proprietary error metric (smaller eRes value suggests a higher-quality and more accurate location estimate) |
Code/software
Excel