We evaluated three walking paces to estimate (1) how snake detection rate per unit distance changes with increasing pace, and (2) how total number of snakes found by the end of a night of surveying varies with pace when the amount of surveying time per night is held constant. For a “fast” pace we searched the 220 meter-long transect in 10 minutes, corresponding to a walking pace of 1.32 km/h, whereas for a “medium” pace we searched 17.5 minutes, corresponding to a pace of approximately 0.75 km/h. The “slow” pace was the 30 minutes (0.44 km/h) the standard previously adopted for work on Guam. Perch height and sizes of detected snakes were recorded for the three paces.

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.

Animals move to locate important resources such as food, water, and mates. Therefore, movement patterns can reflect temporal and spatial availability of resources as well as when, where, and how individuals access such resources. To test these relationships for a predatory reptile, we quantified the effects of prey abundance on the spatial ecology of invasive brown treesnakes (Boiga irregularis). After toxicant-mediated suppression of a brown treesnake population on Guam, we simultaneously used visual encounter surveys to estimate rodent abundance and radiotelemetry to document movement behavior of surviving snakes located in the Habitat Management Unit (HMU) in Northern Guam, Andersen Air Force Base. The impact of prey availability on snake movement is covered under these data via three data files.

Animals move to locate important resources such as food, water, and mates. Therefore, movement patterns can reflect temporal and spatial availability of resources as well as when, where, and how individuals access such resources. To test these relationships for a predatory reptile, we quantified the effects of prey abundance on the spatial ecology of invasive brown treesnakes (Boiga irregularis). After toxicant-mediated suppression of a brown treesnake population on Guam, we simultaneously used visual encounter surveys to estimate rodent abundance and radiotelemetry to document movement behavior of surviving snakes located in the Habitat Management Unit (HMU) in Northern Guam, Andersen Air Force Base. The impact of prey availability on snake movement is covered under these data via three data files.

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.

Data set resulting from monitoring the behavior of snakes (n = 62) that had been feed a standardized large meal with transmitter, proportional to their body mass, to make direct comparisons to a control group of snakes that had not been fed a meal (only the transmitter). Transmitters were equipped with a two-position switch that changes pulse rate when the body position of the animal changes more than 10 degrees from the switch's preset orientation. Changes in pulse rate serve as a proxy measurement for snake activity, under the logic that a relatively stationary/sedentary snake would cause the transmitter to tip less frequently that an actively moving/foraging snake would. The experiment took place in the U.S. Geological Survey's Brown Treesnake study enclosure on Northwest Field of Andersen Air Force Base, Guam.

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.