Petra Wester

Sticky snack for sengis: the Cape rock elephant-shrew, Elephantulus edwardii (Macroscelidea), as a pollinator of the Pagoda lily, Whiteheadia bifolia (Hyacinthaceae).

Following the recent discovery of rodent pollination in the Pagoda lily, Whiteheadia bifolia (Hyacinthaceae) in South Africa, now the Cape rock elephant-shrew, Elephantulus edwardii (Macroscelidea, Afrotheria) is reported as an additional pollinator. Elephant-shrews, live-trapped near W. bifolia plants, were released in two terraria, containing the plants. The animals licked nectar with their long and slender tongues while being dusted with pollen and touching the stigmas of the flowers with their long and flexible noses. The captured elephant-shrews had W. bifolia pollen in their faeces, likely as a result of grooming their fur as they visited the flowers without eating or destroying them. The animals mostly preferred nectar over other food. This is the first record of pollination and nectar consumption in the primarily insectivorous E. edwardii, contributing to the very sparse knowledge about the behaviour of this unique clade of African mammals, as well as pollination by small mammals.

Feeding on the wing: hovering in nectar-drinking Old World birds - more common than expected

Abstract A long-standing paradigm in pollination biology is that New World hummingbirds hover and Old World birds perch when visiting flowers to consume nectar. In contrast, it is now known that hummingbirds perch whenever possible and that nectarivorous Old World birds sometimes hover. However, no overview of hovering behaviour and its frequency in nectarivorous Old World birds exists. This review documents observations of hovering behaviour in 81 species in 11 families of Old World birds, mainly in sunbirds (46 species) and other specialist nectarivores, and less frequently in generalist nectarivores. Hovering behaviour occurs more frequently than thought, not only in terms of the range of avian species but also in its occurrence within species. It was found that neither the geographical distribution of bird species nor their traits (size, body mass) are a limiting factor for hovering behaviour, but that plant traits are important. When perches at the plants are inadequate or lacking, hovering is more appropriate or necessary. It is suggested that, as to foraging behaviour, the distinction between specialist and generalist nectarivorous birds is more adequate than that between hovering hummingbirds and perching passerines. In other words, the foraging behaviour of specialist nectarivorous passerines is more similar to that of hummingbirds than to that of generalist passerines.

To be on the safe site – Ungroomed spots on the bee’s body and their importance for pollination

Flower-visiting bees collect large quantities of pollen to feed their offspring. Pollen deposited in the bees’ transport organs is lost for the flowers’ pollination. It has been hypothesised that specific body areas, bees cannot groom, serve as ‘safe sites’ for pollen transfer between flowers. For the first time, we experimentally demonstrated the position, area and pollen amount of safe sites at the examples of Apis mellifera and Bombus terrestris by combining artificial contamination of the bees’ body with pine or sunflower pollen and the subsequent bees’ incomplete grooming. We found safe sites on the forehead, the dorsal thorax and waist, and on the dorsal and ventral abdomen of the bees. These areas were less groomed by the bees’ legs. The largest amount of pollen was found on the waist, followed by the dorsal areas of thorax and abdomen. At the example of Salvia pratensis, S. officinalis and Borago officinalis, we experimentally demonstrated with fluorescent dye that the flowers’ pollen-sacs and stigma contact identical safe sites. These results confirm that pollen deposition on the bees’ safe sites improves pollen transfer to stigmas of conspecific flowers sti. Future research will demonstrate the importance of safe sites for plant pollination under field conditions.