The forgotten pollinators – First field evidence for nectar-feeding by primarily insectivorous elephant-shrews

Petra Wester

doi:10.26786/1920-7603(2015)14

Abstract

Pollination of plants by non-flying mammals, such as mice (Rodentia), is a rarely observed phenomenon. Previously, elephant-shrews (Macroscelidea), small African mammals looking similar to mice, but not being related to them, were believed to be purely insectivorous and occasional flower visits of elephant-shrews in captivity were interpreted as a by-product of the search for insects. Only recently it was demonstrated that under lab conditions elephant-shrews regularly lick nectar from flowers. However, field observations of flower-visiting elephant-shrews and their role as pollinators were completely missing. Here I present the first evidence for flower visits and nectar consumption for elephant-shrews in the field. With video camcorders and infrared lights I recorded Cape rock elephant-shrews (Elephantulus edwardii) beside Namaqua rock mice (Micaelamys namaquensis) visiting flowers of the Pagoda lily (Whiteheadia bifolia, Asparagaceae) under natural conditions in the Namaqualand of South Africa. With their long tongues, the elephant-shrews visited the flowers non-destructively, definitely licking nectar, but not eating insects. The footage clearly shows that the elephant-shrews’ fur around their long noses touches the pollen-sacs and the stigmas of the flowers and that the animals’ fur is being dusted with pollen. As the elephant-shrews visited several flowers of different plants, it is obvious that they transfer pollen between the plants. This observation contributes to the knowledge about the behaviour of these representatives of a unique clade of small African mammals – especially in their natural habitat. With their behavioural and anatomical uniqueness, it is not unlikely that elephant-shrews even play a role as selective force driving floral evolution. Appendices:Additional supporting information is to be found:Appendix I. With its long tongue Elephantulus edwardii licks nectar from Whiteheadia bifolia flowers, getting dusted with pollen on its nose. Infrared video.http://www.pollinationecology.org/user-files/ JPE349_Appendix1.mp4Appendix II. Micaelamys namaquensis licking nectar from Whiteheadia bifolia flowers, getting dusted with pollen on its nose. Infrared video.http://www.pollinationecology.org/user-files/JPE349_Appendix2.aviAppendix III. Micaelamys namaquensis feeding on pollen-sacs of Whiteheadia bifolia flowers. Infrared video.http://www.pollinationecology.org/user-files/JPE349_Appendix3.avi

Highlights

Pollination of flowers by non-flying mammals is one of the most recently discovered interactions between animals and plants
Elephant-shrews (Macroscelidea), small African mammals looking similar to mice, but not being related to them, were believed to be purely insectivorous and occasional flower visits of elephant-shrews in captivity were interpreted as a by-product of the search for insects
The present study clearly shows at the example of Whiteheadia bifolia that elephant-shrews visit flowers nondestructively for nectar in their natural habitat

Summary

Introduction

Pollination of flowers by non-flying mammals is one of the most recently discovered interactions between animals and plants. This unusual and understudied phenomenon mainly includes marsupials, primates as well as rodents (Buchmann & Nabhan 1996; Carthew & Goldingay 1997; Wester et al 2009). In South Africa, in the recent years, several studies accumulated evidence that mice (order Rodentia) regularly pollinate flowers and that specific plants are adapted to pollination by these animals (Wiens & Rourke 1978; Johnson et al 2001; Wester et al 2009; Johnson & Pauw 2014). Knowledge built up that plant material, such as leaves, fruits and seeds, is eaten by elephant-shrews

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