B2N - Sweet Attractions

by Jamie Walker

Coastal Paperbarks will flower en masse. Conditions are then ideal for their white blossoms to produce nectar; and birds take advantage. Twenty metres up in the canopy, flocks of the larger honeyeaters, like Little Friarbirds, constantly come and go. They seem ever dissatisfied with their immediate location and, with a loud swoosh of wings, chase the illusion that the ‘grass might be greener’ in another tree.

These birds will be joined by many others, and by butterflies which sip at the flowers – endless movement: almost a feeding frenzy.

Sugar is one of nature’s great energy sources. In Australia it is vital because tree nectar is the enticement for birds, bats and small mammals to visit flowers and, at the same time, pollinate them. Without that achievement, we would have no trees – it’s that simple.

As well as nectar, trees offer sugary exudations from leaves and bark; and insects called psyllids suck tree sap, using it to build crystallised sugar shells over themselves. These protect the bugs from dehydration and enemies and are called lerps. They are eaten by small birds like Pardalotes and were an important (and sweetly enjoyable) food for Indigenous people.

Of course, sugar causes problems. We are warned not to give too much to our children. Parents come to understand mood swings and we can also observe frantic behaviour among nectar-feeding birds – who often seem over-energised as they chase and bully one another.

Bell Miners take this to a higher level. They form colonies around psyllid infestations, “farm” and protect the insects (so that they can eat the lerps) and combine to drive away other birds not big enough to resist.

Some birds are so dependent on sugar as a food, scientists call them ‘obligate nectivores’. Swift Parrots (a rare, threatened species) are an example. They breed in Tasmania and endure autumn migration across Bass Strait to escape the island’s sugarless winters. A few reach southern Queensland.

Other birds will make shorter journeys if local eucalypt flowering fails. Musk Lorikeets are common in New South Wales, but when local nectar production occasionally fails they may move north. Early in our autumn, this brought them to Beerwah and the Scenic Rim. They are what we call ‘blossom nomads’.

For many of our birds, sugar is central to their survival, and to the survival of the trees that offer it. If you watch the furious feeding of honeyeaters and others among the blossoms, you might think you are looking at chaos. Yet, as with so much else in nature, what you see is part of something immaculate.