The night survey teams have had a busy month. Due to the predation of nests by foxes, fox baiting was continued with vigour this month, with contract pest control experts arriving during the middle of February to continue their work at Gnaraloo. Gnaraloo commenced a separate but complimentary Fox Control Program during 2008 with the aim of systematically reducing fox numbers to zero in order to protect the turtle rookeries. The program targets foxes in areas within the vicinity of turtle breeding areas in order to protect the egg chambers and later on the hatchlings. However, by clearing the coastal zone nearest to the turtle breeding area of foxes through specialized targeted baiting, foxes from the adjacent zone will move into the cleared zone, which explains the appearance of the fox found on the beach during night monitoring in January 2010.

It was a few weeks further wait, but finally 4 weeks after the night teams first started their monitoring on 4 January 2010, the first hatchlings appeared on 31 January 2010. To date, 8 turtle nests have been recorded as hatching within the night research area. The day team have also reported several nests with hatchling tracks during their morning patrols of the more extensive day research area.
Generally, scientific opinion of Loggerhead (Caretta caretta) hatching events is

of simultaneous emergence of the majority of the neonates (a neonate is a recently hatched or born individual) within the nest in a single go. However, the night teams have recorded variances on this, with mass emergences of 70+ individuals in a single event as well as surfacing of smaller groups (singles, 10s or 20s) over a number of days, ranging from 2 to 5 days.

The survival rate of the hatchlings has been varied, depending on the number of turtles emerging from a nest. An individual hatchling has a greater chance of survival when emerging in large clusters as the chances of it being predated are lessened due to the sheer numbers of its siblings. This has been a consistent finding during the night research, with greater percentage success rates found in nests with mass emergences of 30+ individuals as opposed to nests where hatchlings emerge individually or in twos or threes.

It is too early to say what the final percentage rate of predation of hatchlings will be, but the night teams have noticed high levels of nest predation by Ghost crabs (Ocypode convexas). The crabs burrow down and remove developing eggs as well as prey on emerged hatchlings from the nests. The natural cycle of tides has also affected the turtle nests within the night research area, with several nests situated lower down on the dunes being either washed away by the high tides or the nests flooded, thereby drowning the eggs.

In forthcoming weeks, we are expecting increased numbers of hatchings events and hatchlings of various species on the beach and, hopefully by the end of March 2010, we will have a more informed insights and perspective on the levels of neonatal predation (the predation of recently emerged hatchlings) within the night research area.

The turtle work at Gnaraloo is not only limited to the field research being undertaken by the day and night teams. The interpretation and technical reporting of the field data accelerated this month with renewed vigour, with our researchers now seemingly permanently attached to their laptops. Amy James, one of the day team members, travelled to Geraldton to spend a week with Karen Hattingh, Gnaraloo’s Environmental Advisor, to progress both the Gnaraloo Turtle Monitoring Procedure, containing research protocols, as well as the Gnaraloo Turtle Monitoring Research Report 2009/10, including figures, graphs and maps. The GIS mapping produced a number of challenges currently being working through by the teams. The final season-end report will contain results, discussion, conclusions and recommendations for future seasons.

In addition to this, we have been preparing for the annual site inspection of the Gnaraloo Turtle Conservation Program (GTCP) by the Department of Environment and Conservation – Exmouth District (DEC) on 9 March 2010. The teams, under Karen’s guidance, will give a presentation on the new night component of the GTCP as well as accompany the DEC officers on an escorted tour of the night survey work. A presentation and night tour on the GTCP will also be given to representatives of the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Curtin University and Edith Cowan University on 10 March 2010.

In short, it’s been all hands to deck this month, let’s hope as many turtle hatching events as possible continue into March!
Mike, John, Sergio and Purusha.