Hatchling (naked and may be blind)
These are the easiest of "belly" birds to feed, believe it or not, as they gape very easily at overhead movement, chirps, and slight jostling of the "nest". They also grow extremely fast and are out of this phase very quickly (within two to four days depending on hatch date). GREAT care must be taken to only feed the smallest possible quantities and the babies MUST be fed every 10-15 minutes or they will die. These babies are best to raise when they are in a bunch.
Nestling (pinfeathers or feathers, but not flying yet)
60% DRIED formula and 40% fruit mixed and then warm water added to applesauce consistency. Fruit should be fresh mango, papaya, banana, or any combination of the three, but applesauce or strained fruit baby food can be used if necessary. Add one to two mealworms (DEFINITELY ones who've recently shed their skins - they are white) and bitty bits of soft tofu or boiled egg for additional protein supplement. Protein is important at this stage for proper feather growth. Mejiros at this age should have one feeding per day of straight formula with a pinch of Tang added for sugar. Mejiros are less susceptible to poor feather growth than bulbuls. Pinfeather and feathered babies should be fed every 15 minutes through a twelve-hour period. Mejiro babies will be out of this stage within two to three days max. Take EXTREME caution at this point because one minute you will feeding a bunch of non-flying babies and the next minute they will be leaping out of the nest and, shortly after, buzzing around like bumblebees at the speed of light.
Fledgling (no tail or some tail and flying regardless)
Same mix as above, but formula mix should be pudding consistency (add less water). Two mealworms are okay for this age along with tofu and egg. As the baby gets older, mix the formula to a thick paste consistency and start feeding off of a finger. This will help to transition the bird to solid food. Also at this stage, carefully offer nectar drop by drop from a syringe. Touch it against the tip of the bird's beak and it should quickly learn to suck at it. After about three or so days of feeding the paste formula, tiny bits of fruit. Soft fruit can be given at a younger age, of course, but not to substitute for formula. Start putting pieces of fruit in the bird's cage along with the insect crumble and feed approximately every half hour. Until the bird is actively feeding from the fruit and/or crumble, do not go longer than an hour without offering food. If the bird doesn't want it, offer several drops of nectar. Mejiros can literally run out of "gas" and die at this age if they do not get enough sugar. Once the bird takes nectar readily from a syringe, then a nectar bottle can be put in the cage. Mejiros usually wean themselves when their white-eye ring grows in. Watch carefully and transition at the bird's pace to an adult diet.
Adult
This bird is a nectivore and should be supplied with either soft fruit or nectar, preferably both, at ALL times. Softbill insect crumble is very good, but some birds may not eat it right away. Chopped, boiled egg and tofu in small quantities along with one to two small mealworms are also necessary. The nectar mixture is five parts water, one part sugar and can be put out for three to four days depending on the heat or when the ants get to it. Do NOT offer the Mejiro a standard bird water dish, as they have been known to drown. A bird tube with a tongue (can be found in any pet store) is best. Nectar can be put in this as well, but the bird may take a bath in it. A very small Lix-it bottle made specifically for birds works very well for nectar. Mango, papaya, banana, and orange (in slices only) should be provided and peeled; chopped grape and chopped strawberries can be added as well. Hibiscus and honeysuckle blossoms can be offered, but not plumeria as it is poisonous.
(Adapted from material provided by Merri Keeton)