Topic : Land Birds
Article 15 02 January 2007
Tinkerbirds – mistletoe dispersers
Tinkerbirds are well known as the primary dispersers of mistletoe plants that parasitize many of our indigenous trees. The photographs in this article not only illustrate just how sticky the flesh of these fruits are, but how important these this food source is to these unobtrusive little ‘tinking’ members of the barbet family.
There are 9 species of tinkerbirds, all restricted to the continent of Africa and all belong in the genus Pogoniulus. Although 4 species are officially represented on southern African bird lists, one, Green Tinkerbird Pogoniulus simplex is now considered to be locally extinct. This leaves the three other species, plus Acacia Pied Barbet Tricholaema leucomelas as the primary dispersers of mistletoe plants in southern Africa.
In southern Africa Mistletoes are parasitic plants made up primarily of the families Loranthaceae and Viscaceae. They are represented in the region by 13 Genera with 38 species, most of which are important food sources for tinkerbirds, Acacia Pied Barbets and other frugivores that feed extensively on the sticky fruit. Their flowers too are important suppliers of nectar for sunbird and white-eye species.
The attached photographs of Yellow-fronted Tinkerbird Pogoniulus chrysoconus were all taken in southern Limpopo Province, near Nylsvlei. Mistletoe species represented in this bushveld region include Plicosepalus kalachariensis, P. amplexicaulis, Erianthemum dregei, Tapinanthus quequensis, T. rubromarginatus, Tieghemia bolusii, Agelanthus natalitius subsp. zeyheri, A. gracilis, Viscum rotundifolium, V. verrucosum, V. obscurum and Oncocalyx bolusii.
When the sticky mistletoe seeds are regurgitated, they sometimes drop and stick to the lower branches of the tree, or they may end up stuck to a branch when the birds wipe their bills in an effort to free themselves of this sticky seed.