DOI: 10.5061/dryad.3n5tb2rkn
title: Fijian sea krait behavior relates to fine‐scale environmental heterogeneity in old‐growth coastal forest: The importance of integrated land–sea management for protecting amphibious animals

description: Here the data for "Fijian sea krait behaviour relates to fine-scale
 environmental heterogeneity in old growth forest: the importance of
 integrated land-sea management for protecting amphibious animals" by
 Lowe, C., Keppel, G., Waqa, K., Peters, S., Fisher, R.N., Scanlon, A.,
 Osborne-Naikatini, T, and Thomas-Moko, N  is provided. This
 article investigates the habitat of Yellow Lipped Sea
 Kraits, Laticauda colubrina, in the terrestrial realm on Leluvia
 Island, a small, topographically flat atoll in Fiji with coastal forest.
 The investigation uses concurrent microclimate measurements and behaviour
 surveys, as well as vegetation surveys, and the data collected for these
 analyses are provided here. Microclimates were significantly related to
 canopy cover, leaf litter depth, and distance from the high-water mark
 (HWM). Sea kraits were almost exclusively observed in coastal forest
 within 30 m of the HWM. Sloughing of skins only occurred within crevices
 of mature or dying trees. Resting L. colubrina were significantly more
 likely to occur at locations with higher mean diurnal temperatures, lower
 leaf litter depths, and shorter distances from the HWM. On Leleuvia,
 behaviour of L. colubrina therefore relates to environmental heterogeneity
 created by old-growth coastal forests, particularly canopy cover and
 crevices in mature and dead tree trunks. The importance of healthy coastal
 habitats, both terrestrial and marine, for L. colubrina suggests it could
 be a good flagship species for advocating integrated land-sea management.
 Furthermore, our study highlights the importance of coastal forests and
 topographically flat atolls for biodiversity conservation. Effective
 conservation management of amphibious species that utilise land- and
 seascapes is therefore likely to require a holistic approach that
 incorporates connectivity among ecosystems and environmental heterogeneity
 at all relevant scales.
description: <em>Study
 Design</em> Six transects were established in the forested
 part of Leleuvia Island. Five 55 m transects were positioned perpendicular
 to the coast, commencing at 2 m inland of the high-water mark (HWM) – see
 article for details. Another 65 m transect was established in the centre
 of the island. Each transect was equipped with 7 (55 m transects) or 8 (65
 m transect) Hygrochron DS1923 microclimate sensors (Eclo Solutions)
 located at 2.5 m, 7.5 m, 12.5 m, 22.5 m, 32.5 m, 42.5 m, and 52.5 m (55 m
 transects), and 0 m, 10 m, 20 m, 25 m, 35 m, 40 m, 50 m, and 60 m (65 m
 transect) from the starting point of the transect. These 43 sensors were
 supplemented with 17 additional sensors placed close to resting
 <em>L</em>. <em>colubrina</em>. Of the 60 sensors,
 20 were positioned in areas with kraits present and 40 in areas
 without. Ten of these sensors, five each in locations with
 and without snakes, malfunctioned or were lost.
 <em>Microclimate
 Sensors</em> Microclimate sensors were standardised at room temperature for 24 hours, then
 programmed to record temperature and humidity at 20-minute intervals for
 two weeks. Each sensor was positioned 30 mm (approximately body height of
 <em>L</em>. <em>colubrina</em>) above ground on a
 400 mm wooden stake of 10 mm diameter. A white paper cup, perforated with
 holes to facilitate airflow, was attached above the sensor and used as a
 radiation shield. <em>Snake Surveys</em>
 A survey route (Fig. 2a), which included the six transects
 mentioned above, was established around the island to locate sea kraits. A
 total of 15 surveys were completed over a 9-day period, with surveys
 occurring every second day (on 21, 23, 25, 27 and 29 July 2019) to
 minimise disturbance to the animals. Three surveys were completed on each
 survey day. Surveys started at 9:00, 15:00 and 21:00 hours. The direction
 of travel for each survey was alternated to minimise
 pseudoreplication. <em>Environmental and
 Vegetation Data</em> Data collected for each
 transect point and for each location that a snake was found in included
 the location of each snake using a Garmin etrex 20x GPS (Garmin), the
 behaviour exhibited by the snake (either resting, sloughing, breeding and
 travelling), the percentage canopy cover in a 2-m radius above the snake
 (or transect point), the depth of the surrounding leaf litter using a
 ruler, and the plant species present in a 1-m radius.
 <em>Data Processing</em> Relative humidity collected by the sensors was
 converted to absolute humidity (g.m<sup>-3</sup>) using: AH =
 (6.112 x e^[(17.67 x T) / (T + 243.5)] x RH x 2.1674) / (273.15 + T),
 where T is temperature in °C, RH is relative humidity in %, and e is the
 base of natural logarithms [raised to the power of the contents of the
 square brackets]. the microclimate data (temperature and
 humidity). Temperature and humidity data was split into diurnal and
 nocturnal observations using the following approach in line with the
 Australian Bureau of Metereology (BOM): Night temperatures/humidity for a
 day include temperatures/humidity from one hour after sunset to one hour
 before sunrise in the 24 hours to 9 am, and day temperature/humidity the
 temperatures/humidity from one hour after sunrise to one hour before
 sunset on that day. The data was then used to calculate the mean and
 variance in temperature and humidity for both diurnal and nocturnal
 observations.
description: All data are presented in a single spreadsheet with the following
 sheets: 'Environmental Data'
 includes the site location (longitude and latitude), percentage canopy
 cover, leaf litter depth, distance to the high water mark, and snake
 presence or absence for the 50 locations with retrieved microclimate
 data 'Microclimate Summary - Day' includes
 the means and variances for temperature and absolute humidity data
 collected during the day 'Microclimate Summary -
 Night' includes the means and variances for temperature and absolute
 humidity data collected during the night
 'Microclimate Raw' includes all humidity and
 temperature readings collected from the 50 sensors
 'Snake Survey' includes all the information collected
 during the snake surveys 'Vegetation Data'
 includes the cover-abundance data for plant species collected for each of
 the 37 transect points