Caring for Pollinators - Bundesamt für Naturschutz

Schuchmann Fact sheet pollinators: Avian pollinators: Hummingbirds, Sunbirds,
Honeyeaters, Hawaiian Honeycreepers (Trochilidae,Nectariniidae,
Meliphagidae, Carduelidae)
Sunbirds biology and pollination
Sunbirds are small to medium sized birds of 6 – 30 g.
They occur in almost all tropical and subtropical habitats, reaching high mountain altitudes in
the Himalayas above 3000 m. They mainly forage near water and rarely invade arid areas or
swamps.
The diet of sunbirds consists to a much smaller fraction of nectar than in hummingbirds
(sunbirds less than 40%, hummingbirds over 90%). Their main food constituent are
arthropods (c. 60%; in hummingbirds c. 10 %) (Schuchmann 1984). Besides nectar, fruits,
and pollen are known to be consumed by all sunbirds. Arthropods are frequently collected at
or around flowers. Sunbirds mainly consume nectar while perching. During feeding at
flowers pollen is dusted onto the bill, tonuge, and the feathers. Any that is not consumed will
be carried to other conspecific flowering angiosperms inducing pollination. Many sunbirds
are nectar robbers piercing the bases of corollas thus reducing the chances of pollination.
In sunbirds pollen is deposited mainly on the crown feathers and on the bill. However in the
case of Strelitzia nicolai (Strelitziaceae) pollen seems to be transferred to the reproductive
organs via the feet (Frost & Frost 1981). Sunbirds are generally much less associated with
certain angiosperms. So far the only known exception is the Cape Sugarbirds (Promerops
cafer) which seems to pollinate only South African Protea species (Proteaceae).
Main flower preferences
Common and widely distributed angiosperms, e.g. Leonotis leonurus (Labiatae) and
Strelitzia sp. (Strelitziaceae) are known to be pollinated by sunbirds. Flowering exotic
ornamental plants are frequently visited by sunbirds in search for insects and nectar.
However, these angiosperms rarely depend on sunbirds for pollination. The pollination
syndrome of sunbirds and their flowers is much less known to science than in hummingbirds.
Sunbirds and pollinated crops
No information is available on that topic.
Sunbirds and biodiversity of wild plants
Sunbirds have a wide range of food items (esp. arthropods, fruits) and depend much less on
nectar, which frequently is compensated by sugar-rich fruits. Hence their impact on the
reproductive system and speciation mode of plants seems to be less effective.
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