Helicopter reconnaissance of the Gazelle Peninsula and Central New Britain

Helicopter reconnaissance of the Gazelle Peninsula and Central New Britain

As a prelude to seed collection from natural populations of E. deglupta for provenance studies, a helicopter reconnaissance was organized to map the stands then observable from the air on the Gazelle Peninsula and Central New Britain.

An all-day charter was agreed with Helicopter Utilities who had a machine in Rabaul but could only make it available on a weekend in between other work for another client already underway on weekdays.

Drums of fuel were delivered to the grassed area in front of the Davidson’s house, which was the preferred landing place in Keravat. At 7.00 AM on Saturday 9 June 1968, the helicopter with an engineer on board arrived. The fuel was topped up and the first sortie to the limit of endurance on full tanks was undertaken. The engineer remained on the ground near the landing site to refuel the aircraft after each flight and before returning to Rabaul. The sole passenger was myself, equipped with a camera, some out-of-date air photographs and a sketch map of the area showing the main rivers and some of the smaller tributaries on which the distribution of the main observable pure stands of E. deglupta had been marked in the past and now could be could updated to the then present situation.

The first sortie was to fly southeast from Keravat to pick up the headwaters of the Toriu River and follow it to the coast then turn back for Keravat this time following the Asrogi River from its junction with the Toriu north east to its headwaters.

The second sortie was to pick up the headwaters of the Mevelo River and follow it to its mouth in Henry Reid Bay. Also some other streams in that vicinity and another draining into Wide Bay21 were explored, before again returning to Keravat.

The third sortie was to explore the Sai River and other rivers flowing into Open Bay such as the Mavelu.

On arrival back at Keravat at 2 PM it was decided the weather in Central New Britain was deteriorating too much to allow another sortie. The helicopter was refueled at Keravat and it returned to Rabaul with the engineer on board.

21 Called “Spacious Bay” on some old maps and on the labels of some early botanical specimens of E. deglupta.

Helicopter reconnaissance 1968. Top: From the air, the ease of separation of E. deglupta with its lighter green coloured canopies (arrows) from the surrounding rainforest vegetation was easiest when the light was overhead near midday and the viewing angle was oblique. Bottom: In the morning light and at close range the emergent canopies were obvious (arrows) and the distinctively coloured trunks stood out when viewed from the side, here helped by the open transect made by a logging road near Open Bay.

Helicopter reconnaissance 1968. Top: With the morning light behind the aircraft, the colour difference was less, but the height of the emergent canopies of E. deglupta (arrows) ensured they stood out from the surrounding vegetation. Bottom: In the late seral stage shown here, the rainforest element had almost completely taken over. The slightly lighter and marginally taller canopies of the remaining E. deglupta (arrows) dispersed through the rainforest elements were harder to spot. For this situation, being able to slow the speed over the ground and to descend much lower in a helicopter than in a fixed wing aircraft were particularly helpful.