Available active surveillance efforts for Brown Treesnakes on the island of Saipan via nocturnal visual encounter surveys and trapping from 1999-2018 were collected and summarized into 3 csv files (TRAP1999, BTSRRTSaipanTRAP, and BTSRRTSaipanVISUAL). Location and date of non-confirmed reports of snakes 1982-2013 via passive surveillance were compiled into a fourth file (Saipan BTSSightings1980_2020.csv) with their associated credibility score of 1-5 (5 = completely credible) defined by a panel or small group of Brown Treesnake experts. Trapping surveillance efforts used a modified minnow trap as a snake trap. Traps are suspended horizontally from natural vegetation or fences 1-1.5 meter (m) off the ground. Within each trap, a chamber houses and protects a live attractant mouse. Traps are checked each morning, and the grain mix and potatoes providing food and water for lure mice are replenished as needed. Dead mice are replaced immediately when possible, or within two days; dead mice have been shown to be roughly as attractive as live mice for the first 2-3 days. Traps are deployed along transects-which may be the same transects where nocturnal visual surveys occur-and are spaced roughly 20-40 m apart. Visual surveys occur along forest edges, roadsides, and forest interior (via measured and flagged transects). Observers use headlamps to search for snakes in the vegetation or on the ground. Survey transects are sized so that observers can complete one transect per hour (approximately 450 m/hour(h)) and capped at four transects per searcher per night to avoid searcher fatigue. Observers record start and end times, total actual search time, all vertebrates detected (to gain baseline knowledge of snake prey abundance), and distance in kilometers traversed. Surveys begin 30 minutes after sunset. Since 2004, Commonwealth of the Northern Mariana Islands residents have been implored by radio jingles, posters, and trucks with prominent signage to immediately report sightings of snakes. The islands have a Brown Treesnake Hotline with a memorable number (28-SNAKE) to facilitate reporting. Non-confirmed reports of snakes prior to 2004 were obtained via natural resource and port authority agency memos and memory.

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.

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.

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.

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.

There are two datasets included in this entry. The diurnal dataset contains 28 columns of data collected during transects surveys. The nocturnal dataset contains 52 columns. We randomly select 56 sites, each 50 m in length, from 37,968 m of transects spanning the island that were originally created for bird surveys in 1982 through the cooperative efforts of the U.S. Fish and Wildlife Service, the Department of Natural Resources of CNMI, and the U.S. Forest Service. For diurnal surveys, 56 transects were surveyed twice per day for 1–3 consecutive days resulting in six survey occasions. For nocturnal surveys, we surveyed 51 of the 56 transects 4 times per night for 1–3 consecutive nights resulting in 12 survey occasions. Each survey was alotted ~10 min to complete. All species encountered during this time were recorded. The covariate enhanced vegetation index (10-meter resolution) was derived using Sentinel-2 satellite imagery from dates around and through the sampling periods: 12 June 2018, 22 June 2018, 02 July 2018, 22 July 2018, 27 July 2018, and 11 Aug 2018. Elevation data was resampled to 5-m resolution from a native 3-meter resolution.

There are two datasets included in this entry. The diurnal dataset contains 28 columns of data collected during transects surveys. The nocturnal dataset contains 52 columns. We randomly select 56 sites, each 50 m in length, from 37,968 m of transects spanning the island that were originally created for bird surveys in 1982 through the cooperative efforts of the U.S. Fish and Wildlife Service, the Department of Natural Resources of CNMI, and the U.S. Forest Service. For diurnal surveys, 56 transects were surveyed twice per day for 1–3 consecutive days resulting in six survey occasions. For nocturnal surveys, we surveyed 51 of the 56 transects 4 times per night for 1–3 consecutive nights resulting in 12 survey occasions. Each survey was alotted ~10 min to complete. All species encountered during this time were recorded. The covariate enhanced vegetation index (10-meter resolution) was derived using Sentinel-2 satellite imagery from dates around and through the sampling periods: 12 June 2018, 22 June 2018, 02 July 2018, 22 July 2018, 27 July 2018, and 11 Aug 2018. Elevation data was resampled to 5-m resolution from a native 3-meter resolution.

Data were collected in association with locations of standard brown treesnake traps on Guam at location prior to suppression or control efforts and after control had occurred. In all cases study sites were closed or semi-closed populations of brown treesnakes. Habitat data focused on type and structure of the habitat within 10-m of the trap.