Objective of the flight:
The objective of the flight was to record Denham’s Bustard display areas in a study area comprising a rough triangle between Jeffreys Bay, Hankey and Tsitsikamma in the Eastern Cape. This forms part of a larger initiative which is being undertaken by the St Francis Kromme Trust, a registered public benefit organisation concerned with environmental issues in the greater St Francis Bay area, in co-operation with five wind energy developers in the region.The St Francis Kromme Trust is concerned that the cumulative effect of several planned wind energy developments in the Kouga Municipal area will impact negatively on Denham’s Bustard, particularly through loss of habitat (displacement) but also through mortality through collisions with the proposed turbines. During the course of the discussions between the Trust and several wind developers, it was agreed that a strategic plan is required that details steps that need to be taken to ensure the continued survival of Denham’s Bustard in the Kouga Municipal area. One of the conservation goals that were identified is the need for a sensitivity map that indicates areas of prime habitat for Denham’s Bustard, Blue Crane and White-bellied Korhaan in the Kouga Municipal area.
Avifaunal specialists Chris van Rooyen and Albert Froneman are currently working with the Trust to compile the sensitivity map. They recognised the need for an aerial survey to identify as many Denham’s Bustard display areas (also known as leks) as possible. Lekking is a type of mating system where males defend small, clustered courts that females visit in order to mate. During the lekking season, which peaks in September and October, the displaying males are easily recognised by their balloon displays, which involve the males inflating their pure white neck feathers which are visible up to 1km away. Available information indicates that these lekking sites are used annually, and that most nests are clustered around lek areas, making them key areas for conservation action.
Report from the beneficiary:
“Our strategy was to systematically survey the study area in two mornings by flying parallel transects approximately 1km apart, looking for displaying males and congregations of birds. It is important to do the surveys in the morning between sunrise and late morning, as most of the display activity happens during that time period.
We set out on Wednesday, 25 September 2013, just after sunrise from Plettenberg Bay, where Barry Lipschitz lives, who kindly volunteered to pilot us in his small Jabiru plane. Barry’s hospitality extended beyond flying us, as he also accommodated us at his home for the duration of the survey. The weather was perfect, with scattered clouds and a light wind, with great visibility. We were particularly thankful for the good weather, as not only did it make our job of spotting the displaying males from the air easier, but it also helped us to spot the wind measuring masts scattered across the study area at several proposed wind energy sites. Meeting one of those in mid-air could potentially have been disastrous. Barry, with 30 years of experience flying for the SAAF, was quite unperturbed though and expertly flew us at an altitude of 150 – 300m while we concentrated on spotting the white balloons of the displaying bustard males. We completed our first day of flying mid-morning, when we terminated our surveying and headed back to George to refuel. We had previously decided to take the back-door of the aircraft off to facilitate photography from the air. We flipped a coin the previous evening to decide who will first have the privilege of sitting at the back in an icy wind of 140km/h, and Albert had to bite the bullet. By the time we reached George airport, he was almost hypothermic. We debated the advantages of an open door and I was decidedly relieved when Albert agreed that the open door did not materially improve the chances of spotting birds from the air. The door was promptly fitted at the Jabiru workshop at the George airport after refuelling and I was thus spared the ordeal of trying to photograph birds in the equivalent of an arctic gale the next day! On the way back to Plettenberg Bay from George, Barry treated us to a spectacular close-up view of a Southern Right Whale cow and calf, and an equally close-up view of the Knysna Heads.
The next day, Thursday, 26 September 2013, we headed back to the study area to complete the survey; again we could not have asked for better weather. We flew slightly wider transects as we had calculated that we would not be able cover the whole area if we flew 1km transects. The morning was pretty much a repeat of the previous day, with the highlight of the morning a lek of 6-8 males recorded very close to Humansdorp. We also had the opportunity to view the partially constructed Jeffreys Bay Wind Energy Facility from the air at low altitude. The enormous size of the wind turbines struck us forcibly, emphasising that the South African landscape has changed forever with the advent of wind energy. The morning passed without a hitch and we headed back to Plettenberg Bay around mid-morning, having covered most of the area that we set out originally to do. On the way back we were treated to breath-taking views of the southern Cape coast, and I spotted the water plumes of several whales, a feeding frenzy of waterbirds out on the open ocean, and the shadowy shape of a large shark. What a day at the office….
We had originally hoped to do an absolute count of Denham’s Bustard leks in the study area. It is unlikely that we have succeeded in doing that, as we must have missed some birds from the air. However, the exercise was extremely useful in that it provided us with records of displaying males for areas which are inaccessible from the road. While we still need to analyse the photographs in detail, a provisional viewing of the images confirm that we have recorded at least 20 lekking males, several flocks of Blue Cranes and a Secretarybird. It also provided us with useful information on habitat use of displaying males, and we recorded a major lekking site, one of the biggest on record for the study area. Overall we are satisfied that while the aerial survey did not entirely meet the original objectives, it added significant value and will assist greatly in the compilation of the sensitivity map.
We would like to thank Barry Lipschitz and the Bateleurs for providing us with an invaluable opportunity to broaden our knowledge of the Denham’s Bustard in the study area. This will contribute significantly towards the accuracy of the sensitivity map we are currently compiling.”
Report from the pilot:
“We flew a line pattern from St Francis Bay searching for Denham’s Bustards. I believe (from my passengers) that many were spotted on the two flights and they were delighted with the results.”