Crowned Eagle Research in KwaZulu-Natal: Zimbali Coastal Resort

Invitation article by

Geoff Nichols

Environmental Consultant to Zimbali Coastal Resort

Zimbali Coastal Resort, encompasses 456 hectares – originally 70% forest (a combination of natural forest, sugarcane fields, and plantations of Casuarina and Gum trees) and 30% cultivated land – has, with careful planning and eco-sensitive development, been transformed into 85% development and 15% forest. Owing to the ethos “living in harmony with nature”, Zimbali has matured into a protected natural environment comprising ecological richness and biological diversity.

The developed areas of the estate include private gardens, verges and the golf course – all of which provide refuge to the wide array of birds and animals that would otherwise be unable to inhabit the estate. Although the wetlands have remained intact, Zimbali has lost several “specialist” bird species (mostly due to human disturbance during the early development stages). A number of “generalists” have since taken their place.

Due to the success of the estate’s strict conservation policy, Zimbali Coastal Resort has acted as a conservancy for the re-establishment of many threatened indigenous species, providing a secure home to a variety of local flora and fauna, including over 220 species of bird and no less than 34 species of mammal. Zimbali Coastal Resort has been awarded two environmental accolades: the Nedbank/Mail & Guardian Green Trust Award in the corporate award category (Moreland Developments, 2000); and the more recent award from South African Landscapers Institute(SALI) for the Best Environmental Landscape Work in South Africa (Leitch Landscapes, 2010).

Zimbali Coastal Resort’s habitable environment supports a variety of predatory birds known as raptors. In order for these birds to survive at the top of their food chain and breed, all the other links in this food chain or pyramid must be intact or the raptors will be forced to relocate to a more suitable environment.

There are only about 25 individual birds that prey on other creatures in Zimbali, namely a pair of Crowned Eagles, a pair of African Fish Eagles, two pairs of Yellow-billed Kites that nest on the estate, a pair of Black Sparrowhawk, a pair of African Goshawks, a pair of Little Sparrowhawks, and approximately five pairs of Spotted Eagle Owls.

A single Long-crested Eagle is often seen sitting on posts along the road reserve verges of the M4 provincial road on the west boundary of Zimbali. Among other visitors is an African Harrier Hawk attacking Village Weavers at their nesting colony, as well as Little Swifts colonies under the bridges.

The two raptors most regularly encountered are the African Crowned Eagle and the African Fish Eagle; the former identified by its steep, undulating aerial displays, and the latter by its yelping, echoing call over its open water hunting habitat. Also, the African Goshawk with its high aerial displays above the forest canopy at dawn and dusk while uttering its chik-chik-chik call every few seconds before folding its wings and plunging back down into the canopy.

Besides covering a large area, Zimbali also features sufficient intact coastal lowland forest to support the requisites of a pair of Africa’s largest forest raptor, the African Crowned Eagle. These majestic birds breed approx. 25m from the ground, within view of visitors to the Fairmont Zimbali Lodge. Their aerial mating display is a steep diving, undulating affair high above the forest which is accompanied by their loud yelping call. To hear this evocative call is a spectacular experience.

The pair of African Crowned Eagles returned to Zimbali to breed during the 2001 and 2002 breeding season, and has since fledged nine chicks. These birds only produce one chick per breeding cycle. They prey primarily on Vervet Monkeys and Blue Duiker that they ambush in open glades or verges in the forest. For them to successfully fledge a young eagle there has to be enough food to feed both the parents and the young fledgling. This pair has become quite habituated to humans watching them.

Zimbali has also the most varied set of prey items of any of the urban adapted eagles studied as part of this work. Shane McPherson has identified that, "The parent eagles delivered 87 prey animals to the young eaglet during approximately five months of camera-monitoring. The primary prey includes Vervet Monkeys, Blue Duiker, and Hadeda Ibis nestlings. Prey of secondary importance includes several cane rats, galago's (bushbabies) and mongooses. Interesting one-off records include a young bushbuck, a crested guineafowl, a dove squab, a golden mole, and an owl as well!”

These eagles have given Zimbali Coastal Resort the best environmental achievement award in that the variety of prey items is a reflection of the varied and rich biodiversity of other birds and mammals that live and breed amongst humans.