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 DA 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.
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