For the majority of pterosaur species, it is not known whether they practiced any form of parental care, but their ability to fly as soon as they emerged from the egg and the numerous flaplings found in environments far from nests and alongside adults has led most researchers, including Christopher Bennett and David Unwin, to conclude that the young were dependent on their parents for a relatively short period of time, during a period of rapid growth while the wings grew long enough to fly, and then left the nest to fend for themselves, possibly within days of hatching. Alternatively, they may have used stored yolk products for nourishment during their first few days of life, as in modern reptiles, rather than depend on parents for food. Fossilised "Hamipterus" nests were shown preserving many male and female pterosaurs together with their eggs in a manner to a similar to that of modern seabird colonies. Due to how underdeveloped the chests of the hatchlings were for flying, it was suggested that "Hamipterus" may have practiced some form of parental care. However, this study has since been criticised. Most evidence currently leans towards pterosaur hatchlings being superprecocial, similar to that of megapode birds, which fly after hatching without the need of parental care.