It is unlawful (ḥarām) to eat all birds of prey that have talons, such as falcons, eagles, hawks, and vultures. Similarly, all types of crows, even choughs, are unlawful to eat, based on obligatory precaution (al‑iḥtiyāṭ al‑wājib). Also, every bird that flaps its wings less than it glides while flying and has talons is unlawful to eat. However, every bird that flaps its wings more than it glides while flying is lawful (ḥalāl) to eat.
Therefore, birds that are unlawful to eat can be distinguished from those that are lawful to eat by considering how they fly. However, if it is not known how a particular bird flies, then, if that bird has a crop, gizzard, or a spur at the back of its feet, it is lawful to eat, and if it does not have any of these, it is unlawful to eat.
As for other birds, apart from the ones that have been mentioned, such as chickens, pigeons, sparrows, and even ostriches and peacocks, they are all lawful to eat. However, killing some birds is disapproved (makrūh), such as hoopoes and swallows. As for animals that fly but do not have feathers, such as bats, they are unlawful to eat, so too are bees, mosquitoes, and flying insects, based on obligatory precaution.