Mission: Locating Grey Crowned Crane nest sites
Date: 17 December 2008
Requesting organisation: South African Crane Working Group (SACWG) at the Endangered Wildlife Trust (EWT)
Location: Chrissiesmeer, Mpumalanga
Pilot: Michael Beukman
Late last year we were contacted by Ursula Francke of the South African Crane Working Group (SACWG) at the Endangered Wildlife Trust (EWT). Ursula needed assistance to search for cranes and their nests in two identified sites in Mpumalanga. Michael Beukmann was our volunteer pilot for the flight which took place in and around Chrissiesmeer, in mid-December. Here are the report and photographs from Ursula:
“The South African Crane Working Group (SACWG) of the Endangered Wildlife Trust (EWT) aims to ensure the survival of South Africa’s three crane species (the Wattled Crane Grus carunculatus, the Blue Crane Anthropoides paradiseus, and the Grey-Crowned Crane Balearica regulorum), and their natural habitats. This is achieved by improving our understanding of crane biology, identifying and mitigating human-induced threats, and encouraging the participation and co-operation of communities and institutions, to the benefit of cranes and people.
Towards this goal SACWG field workers are based in all key crane regions in South Africa, including Mpumalanga. One of the important crane locations within Mpumalanga is Chrissiesmeer and the surrounding areas. Both Blue Cranes and Grey Crowned Cranes breed here during the summer months. Since cranes prefer as little disturbance as possible when they are breeding, almost all the nesting sites are far from public roads and areas frequented by people. Grey Crowned Cranes often nest in wetlands characterised by tall reeds which makes sighting a nest or a breeding pair even more difficult.
However, Grey Crowned Cranes and their nests can easily be seen from the air. They are large birds with conspicuous white markings on their wings, making aerial observation quite easy. Exact data was not available for the optimal breeding time around Chrissiesmeer but it was agreed that December should be the peak breeding month for these cranes.
Regions to be covered
The flight focused on the lakes and pans surrounding Chrissiesmeer, passing the western side of Warburton and stretching to the western and south-western parts of Lothair. We tried to cover as many wetlands and pans as possible where we expected to find Grey Crowned Cranes. The route, as measured in ArcGIS 9.2, was just over 200 km in length.
Objectives of the flight
The primary objective of the flight was to locate as many Grey Crowned Crane nest sites as possible. Secondly, we wanted to check whether we could find any Grey Crowned Crane summer flocks, also known as floater flocks. Finally, there were also two historic Wattled Crane breeding sites on the planned flight route in the Lothair/Warburton area, for which we hoped to determine current habitat use.
During the flight we located two Grey Crowned Crane pairs at previously unknown locations and one active Grey Crowned Crane nest site. These sites were not in tall reed pans as we had expected, but rather in short sedge wetlands. At the first two sites we saw both cranes foraging, and at the third site we saw only the incubating bird sitting on the nest. The partner could not be seen in the vicinity. As we flew over, the crane got up and we could clearly see two eggs in the nest.
A nest had been reported at the Tevredepan reed pan during the last breeding season but unfortunately we found no cranes there in December. Another short sedge wetland (Slanghalsvlei) where a breeding pair is usually seen was also without any cranes on the day.
On inspection we found that both historic Wattled Crane nest sites had been abandoned. At the first site the wetland in which they had bred was now dammed up with farm buildings and plantations, and at the second site plantations covered the wetland completely.
Only one active Grey Crowned Crane nest with two eggs was found, while another two Grey Crowned Crane pairs were seen at previously unknown locations. No floater flocks were found in the area. We don’t know if the low number of observed cranes was due to a late start to the breeding season, or because the route focussed on less important areas, or was simply bad luck on a particular day. Continued field work around the Chrissiesmeer area will be able to shed some light on this. The flight also indicated which habitat types should be searched during future nest searches in the area.
A special thank you goes to Michael Beukman who spent many hours in the air flying to Ermelo, doing the route around Chrissiesmeer, and then flying home, not all in ideal weather conditions but all with great skill. Flying in a microlight for the first time gave me some insight into “flying like a bird” – it was a fantastic experience!”