Ecologically Correct Juvenile Phoenix

Question

The phoenix is a bird that closely resembles a large eagle, but is distinguished by its life-cycle: Rather than laying eggs, they produce 2-3 small worms as they die and burn up, which feed on their remains. These worms are soft-bodied arthropods, around 10cm long but quite thin. They gradually grow and develop, and slowly but surely develop into more phoenices

However, this presents the issue that the worms will, at some point in their development, need to find another food source once they have exhausted their parent's flesh. Are there any niches that the young phoenices could fill as they grow?

The phoenices dwell in the Arabian Peninsula. The worms (before beginning metamorphosis) resemble maggots, but with many jointed legs like a pauropod and mandibles adapted for grazing and tearing cooked flesh

The metamorphosis starts once the worms fully eat their parent's corpse and takes around 3 months. The process would involve the worm growing into avian proportions, developing 4 new limbs on the back which become the wings and legs, and the internal parts specializing to become avian. The cuticle and worm-legs would also be permanently moulted and replaced with avian skin at some point in the development. These processes would happen gradually over the 3 months of metamorphosis

Answer 1

Forest fires

Many ecospheres actually expect a forest fire every so often. Fire leaves fertile soil (if it isn't eroded) and removes most low foliage as well as some larger foliage. That means there's space and food to grow for a lot of species.

A phoenix can do just that. I gather from your story the worms feed on the burned up remains of the phoenix. Burned life is nearly identical in its chemical bonds, resembling something like charcoal. So a phoenix can go to a good area, burn up and set a fire. This can help some plants to grow, as well as leave a larger area of burned up life as a food source for the worms.

This can then be incorporated in more lifeforms in the area. They expect a more frequent fire, allowing for many opportunities for new life. The phoenix young are just one in many to take advantage.

Answer 2

Volcanically active areas

The remains of their parents are virtually identical to spent/burnt carbon, char and ash, so why not place them in a region where there's bound to be a lot of it? Volcano goes off, ash falls, worms feast on the layers building up and become fat and happy before their eventual metamorphosis into the pheonix.

Should an area cease to be active for some reason the birds could fly to another one that is active and continue their existence there. The birds would be able to tell its activity by the rumblings and the heat of the area and would then determine whether or not it's a good place for them to die should they eventually do.

The only problem the worms would then have are predators and lava flows, but I'll assume they have that covered, somehow.

Some volcanoes of your peninsula