No, they are not mammals.
Birds do not have periods. They lay eggs.
No. Periods are seen only in placental mammals. Birds do not have them.
The first true birds likely evolved in the Late Jurassic and Early Cretaceous periods.
Yes, they are birds of the savannah and have evolved to do just that.
Birds do not menstruate ("have periods"). Only mammals menstruate. If a female bird has blood or non-feces discharge coming out of her cloaca, she needs immediate medical attention. Birds can bleed to death very quickly.
migration
Kiwi are birds, so they do not have gestation periods: they have incubation periods for their eggs.The incubation period for a kiwi egg is around 23 days.
If birds are going to fly for long periods of time to distant locations during migration, then they will burn a lot of energy.
Birds get there energy for eating, they digest the food that gives them energy. They can fly by having hallow bones, they use there energy as efficiently as possible so they can fly for long periods of time.
Birds and dinosaurs existed at different time periods. Therefore, birds cannot fight, let alone kill, a dinosaur, so a bird can't do anything to kill a dinosaur. i love Amy
Birds can hover in place for short periods of time, but they typically need to move forward to stay airborne due to the way their wings generate lift.
The updraft winds that birds soar on are weaker over water so larger wings allow them to ride these updrafts. Birds will soar whenever possible to conserve energy and can often go for hours without flapping their wings. Many birds that spend long periods of time over water have larger wings in comparison to land birds.