LINE TRANSECT SURVEYS
FIELDWORK EXPERIENCE
My first experience with line transect surveys was on the 'Amazon Biodiversity and Carbon expeditions', during which I was responsible for the biodiversity inventory of large terrestrial vertebrates. To complement detection methods such as acoustic monitoring, camera trapping and eDNA collection, we made use of line transect surveys.
Per rain forest landscape, we established three transects of 3-km length. Using a three-day rotation schedule over the course of 3 weeks, we walked one transect per day, starting at sunrise and walking at 1.25 km/h until the end of the transect. For each detected vertebrate species, we noted the time of detection, location on transect, perpendicular distance from transect, height from ground, species name, number of individuals, group spread and detection cue (visual, auditory, track, etc...). Where possible, all distance measurements where made using a laser rangefinder. In addition to this detection data, we opportunistically collected subsidiary information such as activity, diet, gender, age, mixed association or vegetation characteristics. Finally, for each day, we recorded the date, start time, weather condition and observers walking the transect. Species were also recorded opportunistically when detected on the walk back to the start of the transect, recording the species name only. Using this line transect data, species density can be estimated using distance sampling methods.
Per rain forest landscape, we established three transects of 3-km length. Using a three-day rotation schedule over the course of 3 weeks, we walked one transect per day, starting at sunrise and walking at 1.25 km/h until the end of the transect. For each detected vertebrate species, we noted the time of detection, location on transect, perpendicular distance from transect, height from ground, species name, number of individuals, group spread and detection cue (visual, auditory, track, etc...). Where possible, all distance measurements where made using a laser rangefinder. In addition to this detection data, we opportunistically collected subsidiary information such as activity, diet, gender, age, mixed association or vegetation characteristics. Finally, for each day, we recorded the date, start time, weather condition and observers walking the transect. Species were also recorded opportunistically when detected on the walk back to the start of the transect, recording the species name only. Using this line transect data, species density can be estimated using distance sampling methods.
