The dataset consists of two spreadsheets that contain brown treesnake data (location, perch taxa, perch height, time of detection, whether visible or not, and size of snake) collected during both visual surveys and radio telemetry within a 55-ha enclosure on Guam.

This data was collected as part of a larger project to examine predator-prey interactions between invasive Brown Treesnakes (Boiga irregularis, predator) and native prey species at a study site located in a peri-urban area of Andersen Air Force base in Guam, USA. This dataset includes two datasets. One dataset contains 22 columns and includes data collected on Brown Treesnakes captured between 23 December 2019 and 03 October 2022 during nocturnal surveys. The second dataset that contains 10 columns that describe 1240 individual trees at the study site that served as our sampling unit for the surveys.

Data fall into three types: 1) individual snake scanning data (PIT tag ID, time stamp, and device) downloaded from readers, 2) individual trait data (sex, size, etc) of tested brown treesnakes, and 3) detailed transcripts of videos of behavioral trial data as snakes interacted with the readers. All data were collected in an experimental arena in Dededo, Guam in August 2021.

Data fall into three types: 1) individual snake scanning data (PIT tag ID, time stamp, and device) downloaded from readers, 2) individual trait data (sex, size, etc) of tested brown treesnakes, and 3) detailed transcripts of videos of behavioral trial data as snakes interacted with the readers. All data were collected in an experimental arena in Dededo, Guam in August 2021.

Nocturnal visual encounter surveys for Brown Treesnakes were collected and summarized into 4 plain text files (csv format): CapturesLure, SurveysLure, CapturesScent, and SurveysScent. Capture files contain unique Passive Integrated Transponder (PIT) tag identification and measurements of snakes with dates and locations of capture. Survey files contain the dates of transect sampling and treatment application for each transect (Transect ID). Each project used a different type of attractant, either a live-mouse lures in snake traps or liquid fish fertilizer scented spray. Surveys were conducted in a 5-ha geographically closed population on Guam. Teams of two observers conducted night-time surveys from February 1 to March 31 2015 (live-mouse lure project) and November 1 to December 30 2016 (spray scent project). Visual surveys occurred along maintained 220-meter long transects at 8 meter spacing. Observers used headlamps to search for snakes in the vegetation or on the ground. Observers recorded snake identification, measurements, capture location, and date. Surveys began 30 minutes after sunset. For the lure study, transects either had no traps and live mouse lures (NTL) placed on them or had snake traps with live mouse lures (TL). Snake traps were modified minnow traps. Traps were suspended horizontally from natural vegetation 1-1.5 meter (m) off the ground. Within each trap, a chamber housed and protected a live-mouse attractant. Traps were deployed along the same transects where nocturnal visual surveys occurred. For the spray scent study, transects were either unsprayed (1) or sprayed either in the early evening before the night-time survey (2) or the previous day (3). Spray scent consisted of 500 milliliters of Alaska Fish Fertilizer and 14.74 liters of water and was sprayed along the entire length of a transect using a spray backpack over the course of four minutes to ensure a consistent application rate. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Nocturnal visual encounter surveys for Brown Treesnakes were collected and summarized into 4 plain text files (csv format): CapturesLure, SurveysLure, CapturesScent, and SurveysScent. Capture files contain unique Passive Integrated Transponder (PIT) tag identification and measurements of snakes with dates and locations of capture. Survey files contain the dates of transect sampling and treatment application for each transect (Transect ID). Each project used a different type of attractant, either a live-mouse lures in snake traps or liquid fish fertilizer scented spray. Surveys were conducted in a 5-ha geographically closed population on Guam. Teams of two observers conducted night-time surveys from February 1 to March 31 2015 (live-mouse lure project) and November 1 to December 30 2016 (spray scent project). Visual surveys occurred along maintained 220-meter long transects at 8 meter spacing. Observers used headlamps to search for snakes in the vegetation or on the ground. Observers recorded snake identification, measurements, capture location, and date. Surveys began 30 minutes after sunset. For the lure study, transects either had no traps and live mouse lures (NTL) placed on them or had snake traps with live mouse lures (TL). Snake traps were modified minnow traps. Traps were suspended horizontally from natural vegetation 1-1.5 meter (m) off the ground. Within each trap, a chamber housed and protected a live-mouse attractant. Traps were deployed along the same transects where nocturnal visual surveys occurred. For the spray scent study, transects were either unsprayed (1) or sprayed either in the early evening before the night-time survey (2) or the previous day (3). Spray scent consisted of 500 milliliters of Alaska Fish Fertilizer and 14.74 liters of water and was sprayed along the entire length of a transect using a spray backpack over the course of four minutes to ensure a consistent application rate. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

The dataset contains 16 columns of data collected on invasive Brown Treesnakes (Boiga irregularis) at a study site known as the Habitat Management Unit (HMU) in northern Guam. Snakes were fitted with radio-transmitters and teams of 2-4 biologist listened for signals from transmitters every seven days to determine if snakes were alive or dead. Survival data was then modeled in Program MARK to assess the effect of aerially applied toxic baits on snake mortality, including the effect of snake size covariates. In addition, this dataset contains snake capture information from reference sites on Guam that was used to demonstrate that our sample was representative of the size distribution in limestone forest habitat on Guam.

Visual survey data for brown treesnakes from caves with and without swiftlets. Each record (line) represents the snake sightings that occurred during a block of time, typically 1 hour at one site by searcher(s) during one search (i.e. one date). Snakes removed from caves and adjacent areas during visual surveys were then necropsied. Each record (line) represents necropsy results for a given individual.

Visual survey data for brown treesnakes from caves with and without swiftlets. Each record (line) represents the snake sightings that occurred during a block of time, typically 1 hour at one site by searcher(s) during one search (i.e. one date). Snakes removed from caves and adjacent areas during visual surveys were then necropsied. Each record (line) represents necropsy results for a given individual.

These data were generated during a USGS Rapid Response for brown treesnakes (Boiga irregularis) on Cocos Island Guam (Islan Dåno’, Guåhan in CHamoru). They represent data collected during nocturnal visual surveys for brown treesnakes and data associated with captured snakes, effort during visual surveys as time and distance, as well as lizards, birds, and bats encountered during transect surveys. These data represent all data collected from the onset of the rapid response in October 2020 through a typhoon that caused major site disturbance in May 2023. Data represent only USGS efforts during the specified time period. Additional data may be available for other organizations operating during the specified time period.