Night verification surveys

Careena, Justine and I (Danica) have completed the first period of Night Surveys which started on 8 December 2012 and finished on 19 December 2012 at 2 AM. This work allowed us to physically see the nesting turtles in action as we patrolled the beach. I have been lucky enough to be involved each night during this period and have been amazed at the effort that the female turtles go to, climbing 1m dunes and escarpments, in attempts to nest.

Night observations are used to verify the data collected during the Day Surveys (from tracks only) to quantify the margin of error. The night monitors visually identify the turtle species using field identification techniques and also observe the nesting activities undertaken by the female turtle. The following morning, the day monitors interpret the tracks lefts by the female turtles. After the conclusion of the Day Survey, the night and day results are compared against each other for accuracy. The night data is taken as the accuracy measure as the night teams sight actual turtles. While our goal is 100% data accuracy for turtle species identifications and nesting activity determinations, as the Day Survey work rely on interpretation of tracks and environmental evidence without sighting of the actual turtles, it will not always be 100% accurate which is why it is important to quantify our margin of error for the season.

To minimise disturbance to the emerging and nesting females, we practiced the turtle watching mantra of ‘Stop, Drop, Become a Rock’, which is especially important when they first emerge onshore from the ocean. As we continued to monitor the females, we practiced ‘No glow, Stay low, Move slow’. By keeping to these simple protocols, we were able to see several loggerhead females (Caretta caretta) digging nests and laying their eggs. In total, we observed 19 such nesting activities within this block of night verification surveys.

The Night Surveys will be continuing during January, so stay tuned!

Danica