Register      Login
Emu Emu Society
Journal of BirdLife Australia
RESEARCH ARTICLE

Do sugarbirds feed on arthropods inside or outside Protea inflorescences?

K. M. C. Tjørve A B E , G. H. Geertsema C and L. G. Underhill D
+ Author Affiliations
- Author Affiliations

A Department of Zoology, University of Stellenbosch, Private Bag X01, Matieland, 7602, South Africa.

B Lista Bird Observatory, Research Group, Strandveien 2, N-4563 Borhaug, Norway.

C Department of Entomology, University of Stellenbosch, Private Bag X01, Matieland, 7602, South Africa.

D Avian Demography Unit, Department of Statistical Sciences, University of Cape Town, Rondebosch, 7701, South Africa.

E Corresponding author. Email: kmctjorve@yahoo.co.uk

Emu 105(4) 293-297 https://doi.org/10.1071/MU04042
Submitted: 22 September 2004  Accepted: 2 September 2005   Published: 21 December 2005

Abstract

The nectar of Protea inflorescences attracts sugarbirds (Promeropidae) as well as a large diversity of arthropods. In addition to feeding on nectar, sugarbirds feed on arthropods; but do sugarbirds feed on the arthropods within Protea inflorescences? Through the use of arthropod collections from within Protea inflorescences and diet sampling data from previous studies together with arthropod samples collected during the current study, we investigated whether sugarbirds fed on arthropods found inside Protea inflorescences or whether most arthropods taken were flying arthropods, seldom found in Protea inflorescences. Cape (Promerops cafer) and Gurney’s (Promerops gurneyi) Sugarbirds showed a strong preference for flying insects, tourist or visitor species to Protea inflorescences, particularly Scarabaeidae and Apidae. Cape Sugarbirds showed a preference for Diptera and Gurney’s Sugarbirds showed a preference for Heteroptera. Small arthropods found within Protea inflorescences, for example ants, may be eaten accidentally while the sugarbirds are feeding on nectar. The results of this study support the hypothesis that sugarbirds feed on arthropods by hawking rather than obtaining them from within Protea inflorescences.


Acknowledgments

Kate Henderson and Joelene Hughes assisted in fieldwork. This project was supported by grants from the University of Stellenbosch Research Fund, National Research Foundation (NRF), BirdLife South Africa, Cape Bird Club, KwaZulu-Natal Ornithological Trust and the University of Cape Town Research Committee.


References

Acocks, J. P. H. (1953). Veld types of South Africa. Memoirs of the Botanical Society of South Africa 28, 1–192.
de Swardt D. H. (1997). Gurney’s Sugarbird Promerops gurneyi. In ‘The Atlas of Southern African Birds’. (Eds J. A. Harrison, D. G. Allan, L. G. Underhill, M. Herremans, A. J. Tree, V. Parker and C. J. Brown.) pp. 486–487. (BirdLife South Africa: Johannesburg.)

de Swardt D. H. (1998). Aspects of the behaviour and ecology of Gurney’s Sugarbird Promerops gurneyi Verreaux, 1871, in Protea woodland, South Africa. M.Sc. Thesis, University of the Free State, Bloemfontein.

de Swardt, D. H. , and Louw, S. (1994). The diet and foraging behaviour of Gurney’s Sugarbird, Promerops gurneyi. Navorsinge van die Nasionale Museum, Bloemfontein 10, 246–258.
Fraser M. W. (1997). Cape Sugarbird Promerops cafer. In ‘The Atlas of Southern African Birds’. (Eds J. A. Harrison, D. G. Allan, L. G. Underhill, M. Herremans, A. J. Tree, V. Parker and C. J. Brown.) pp. 484–485. (BirdLife South Africa: Johannesburg.)

Jacobs, J. (1974). Quantitative measurement of food selection: a modification of the forage ratio and Ivlev’s electivity index. Oecologia 14, 413–417.
Crossref | GoogleScholarGoogle Scholar | Maclean G. L. (1993). ‘Roberts’ Birds of Southern Africa.’ 6th edn. (John Voelcker Bird Book Fund: Cape Town.)

Mostert D. P. (1974). The biology of Promerops cafer with special reference to the role of nectar and satellite insect fauna of Protea repens in the reproductive cycle. M.Sc. Thesis, University of Stellenbosch.

Mostert, D. P. , Siegfried, W. R. , and Louw, G. N. (1980). Protea nectar and satellite fauna in relation to the food requirements and pollinating role of the Cape Sugarbird. South African Journal of Science 76, 409–412.
Rebelo T. (1995). . ‘SASOL Proteas. A Field Guide of the Proteas of Southern Africa.’ (Fernwood Press: Cape Town.)

Skead C. J. (1967). ‘The Sunbirds of Southern Africa, also the Sugarbirds, the White-eyes and the Spotted Creeper.’ (AA Balkema: Cape Town.)