Peter and Lynne Hill, of Mosgiel, asks :-
How do nectar feeding birds, such as tuis, feed their young?
Ed Waite, an ecologist at Otago University, responded.
Watching native birds, such as tuis, feeding in the garden is a great way to relax and enjoy a bit of wilderness from the comfort and convenience of your own back yard. Planting native flowering trees and shrubs such as flax, kowhai and fuchsia is a sure fire method of attracting them, and planting a variety of plants which flower at different times of the year will ensure a steady supply and keep the birds coming back for more. Artificial feeders can also be valuable, but should be cleaned regularly to prevent the spread of disease.
However while nectar is a vital source of energy for tuis it does not contain the nutrition and protein necessary for producing eggs and raising chicks. From the start of the breeding season, around September, invertebrates such as insects and spiders make up an increasingly important part of the balanced tui diet. From this time of the year tuis can be observed catching insects in flight (‘hawking’), and also thrashing around in shrubs looking for food items such as stick insects, beetles and cicadas.
Tuis typically lay three eggs, which hatch after about 14 days. At first only the female feeds the young, though the male soon starts to help out. At first small insects are fetched and are fed whole or in pieces, and nectar is transported to the nest in the adults crop and regurgitated for the young. When the chicks are big enough whole berries and larger invertebrates will also be fed. The young leave the nest around 21 days after hatching, though remain dependant on the parents for up to two weeks after this. The adults may then re-nest if conditions are favourable, or they just get back to relaxing and enjoying the abundance of nectar in your garden.