Raptor Research

Coordinator

Dr Andrew Jenkins

Research Team

Prof. Phil Hockey (PFIAO), Dorine Jansen (PFIAO), Ann Koeslag (Cape Bird Club), Lucia Rodrigues, Dr Rob Simmons (Honorary Research Associate, PFIAO),  Mr Anthony van Zyl (Research Associate, PFIAO) & Dr Bettine Jansen van Vuuren (Department of Zoology, University of Stellenbosch),

Affiliated Institutions

Birds of Prey Working Group (Endangered Wildlife Trust),

Overview

Birds of prey are generally rare, charismatic, top-of-the-food-chain predators, often suitable as indicators of environmental health, and ideal as icons for broader conservation initiatives. The Western Cape Raptor Research Programme is the administrative umbrella for a growing number of research projects focused on the biology and conservation of raptors and raptor habitats in the Western Cape Province, South Africa. The programme includes established, long-term studies of raptor populations in the Cape Town area, and newer, more applied projects on raptors and land-use in the Karoo and Fynbos biomes. An important objective of the programme is to identify the conservation needs of the region’s birds of prey, and to develop parallels, overlaps and synergies between these needs and broader, human issues of regional and national environmental health and socio-ecomomic upliftment.

Conservation of the Black Harrier in the Western Cape Province: the effects of land transformation on population status

Research Team: Andrew Jenkins & Rob Simmons

The Black Harrier Circus maurus is one of 16 species of harriers worldwide, with the most restricted range of any continental species. Endemic to the grasslands and fynbos of southern Africa, it has been the subject of only one breeding study, and is classified as locally `Near-threatened’ and globally `Vulnerable’. Its world population is estimated at fewer than 1000 birds, of which less than 100 occur in protected areas. This study aims to investigate the breeding ecology and resource requirements of Black Harriers, with a view to improving management strategies to meet its conservation needs. Specifically, the project will compare the natural history of the species in different habitats, and analyse the effects of landscape characteristics on harrier distribution. This is of particular relevance given that large areas of the harrier’s range have been transformed by agriculture. Data from regular surveys of the West Coast and Overberg regions will be used to examine the relationship between the degree of fragmentation of natural habitat and harrier population size.

The Black Harrier project is largely funded by the Critical Ecosystem Partnership Fund (CEPF) and is part of the C.A.P.E. (Cape Action Plan for People and the Environment) initiative. As such, an important element of the project is to encourage the `buy-in’ and involvement of civil society (e.g. landowners, conservators, birders) in developing a sustainable research and management network, using the Black Harrier as a conservation flagship and/or an indicator of habitat health.

Breeding performance and survival of Peregrine Falcons on the Cape Peninsula: the influence of nesting habitat quality

Research Team: Andrew Jenkins

Although the biology of the Peregrine Falcon Falco peregrinus is intimately known in many parts of its cosmopolitan range, understanding of the demography of Peregrine populations is surprisingly poor. The few studies that have yielded good information on population dynamics are from northern temperate and Arctic areas and, as yet, no comparative figures are available for African or any other southern Hemisphere populations. This project builds on over a decade of research on aspects of Peregrine biology on the Cape Peninsula, and focuses on the dynamics of this population – primarily survival, turnover and recruitment rates. In the long-term, the study will emphasize the relative influence of crucial features of the nesting habitat on the lifetime reproductive success of individually marked birds.

Breeding biology and ecology of the Rock Kestrel in the southwestern Cape, South Africa

Research Team: Anthony van Zyl

The Rock Kestrel F. tinnunculus is a widespread and fairly common species in southern Africa, and occurs at particularly high densities in parts of the southwestern Cape. The present study has compared aspects of kestrel biology in this south temperate area with those of tropical and northern temperate populations, with a view to testing theories on the effects of latitude on life history strategies. Future objectives include assessments of the effects of overly frequent fires and the spread of urban development on the biology and success of kestrel pairs on the Cape Peninsula.

The natural history of the Black Sparrowhawk on the Cape Peninsula, South Africa: habitat manipulation and unusual life history traits in a founder population

Research Team: Ann Koeslag & Phil Hockey

The natural history of the Black Sparrowhawk Accipiter melanoleucus is poorly known, despite the fact that it is the largest and one of the more common forest hawks in Africa. It is a fairly common species in the southwestern Cape, and a healthy population has been resident on the Cape Peninsula since at least the late 1980’s. It is uncertain whether the species is a new arrival to the area, or was resident here before the removal of indigenous forests in the 1600’s, and has since re-colonised the Peninsula with the establishment of exotic plantations as a substitute for its natural breeding habitat. This project will research various aspects of Black Sparrowhawk biology, including habitat use, diet and population dynamics. In addition, two particularly interesting issues warrant further investigation: (i) How do the hawks respond to anthropogenic changes to the local environment? As fast as territories are established by new pairs in what has been an expanding population, others are lost as the `Working for Water Project’, focused on the removal of alien trees, gathers momentum in the area. (ii) Winter-breeding and double-brooding have been reported for Black Sparrowhawks on the Cape Peninsula. Should these reports be verified, the study will assess the environmental features that allow such unusual breeding strategies, and examine their effects on breeding success and the survival of adults and offspring.

We need your help!

While securing the funding for research projects, and particularly for raptor studies, is always difficult, we have reached a stage in the development of the WCRRP where perhaps our most limiting factor is the availability of personnel to achieve the tasks that we have set ourselves. Part of the solution to this problem lies in our local tertiary institutions, and we hope to extend the academic horizons of the programme, and take on more post-graduate students, in the near future. Another important resource that remains largely untapped is the Western Cape birding community, and we would like to appeal to you, the birding public, to participate in some aspect of field data collection for any and all of the projects within the WCRRP.

For Cape Town birders, one way in which you can help is to 'adopt’ one or two raptor nest sites in your area of the Peninsula, and keep an eye on activities there through the breeding season, letting us know if and when the birds appear to have laid eggs or started to feed young. With some initial guidance, this wouldn’t require much more than two or three visits to the relevant area each breeding season. Establishing a network of such observers to keep tabs on at least some of our study sites would free us up for the more hands-on work – nest visits, ringing etc - and allow us to use our time more productively. On a broader front, the harrier project is about to launch a major public-participation campaign, aimed at involving birders, conservators and landowners in collecting data to help us learn more about the nesting and foraging habitat requirements of the Black Harrier.

Acknowledgements

All of the projects listed above are independently funded. We would like to acknowledge the financial support of the Critical Ecosystem Partnership Fund, Peregrine Properties Pty Ltd.