is unclear if one or both parents feed the young, but, as in other parrots, the female probably stays with them for the first few days while fed by the male, and when the young are homeothermic (have a stable body temperature), both take care of and feed the nestlings. Two of the young are normally raised. Chicks develop slowly, with dark feather tracts visible on the back and primary quills after five days. The tracts are more visible after ten days when down tips breakthrough, their eyes are slit-like as they begin to open, and the legs turn from pinkish to pale grey. The eyes are almost fully open after fifteen days, and the chicks have a fine covering of greenish-grey down on most of the body, the secondary quills emerge, and feather tracts appear on the crown of the head. They are completely covered by greenish down after twenty days, and after thirty days the wing and tail feathers emerge. After forty days, all contour, wing, and tail feathers are well developed, but down is still retained on the lower parts and flanks. When nestlings are developed enough, they can threaten nest intruders with loud growls and bites but will retreat into nooks and stay still if the intruder persists. After fifty days, the chicks are rather active, flapping their wings and venturing near the entrance hole. Chicks fledge after 50–60 days, between late October and February, and fledglings remain near the nest entrance sometime after leaving. They accompany their parents to forage as soon as they can fly, and remain with them and are fed for two to three months after leaving the nest. The young have been observed imitating adults which were carefully selecting fruits, and have been observed being fed by adults as late as March. Additional adult male echo parakeets acting as "helpers" by feeding the nesting female and the nestlings (usually rebuffed by the nesting pair, but sometimes disrupting nesting by making the pair leave their nest) were speculated to be correlated with a skewed sex ratio in the 1980s. The "helpers" were thought to be perhaps a recent phenomenon, possibly due to the destruction of foraging areas, and many non-breeding birds consequently being displaced to other areas, creating an unsustainable excess in the populations there. In the late 1990s, it was reported that the echo parakeet is perhaps not monogamous, but has