Flightless bird that require a significant amount of overall metabolic energy, ratites decrease their basal metabolic rate and conserve energy. A study looking at the basal rates of birds found a significant correlation between low basal rate and pectoral muscle mass in kiwis. On the contrary, flightless penguins exude an intermediate basal rate. This is likely because penguins have well-developed pectoral muscles for hunting and diving in the water. For ground feeding birds, a cursorial lifestyle is more economical and allows for easier access to dietary requirements. Flying birds have different wing and feather structures that make flying easier, while flightless birds'
Flightless fruit fly as convenient feeders for a variety of companion animals and even as test subjects in aeronautical research Flightless fruit fly Flightless fruit flies (Order Diptera) encompasses a variety of different species of fly, such as "Drosophila melanogaster", "Bactrocera cucurbitae", "Bactrocera dorsalis", and "Drosophila hydei", with genetic mutations that cause them to be flightless. These genetic mutations may have different results such as the development of muscles that cannot support flight or even result in the lack of wings entirely. Flightless fly models have been especially useful for the study of human neuromuscular diseases such as spinal muscular atrophy, spinobulbar muscular