If a grebe is found grounded on land, what is often necessary before it can successfully fly again?
Answer
Time on the water to rebuild necessary muscle strength.
If a grebe arrives injured or exhausted, such as after strong weather, it needs time on a body of water to regain the muscle fitness required for a successful, energy-intensive flight.

Related Questions
What type of foot structure do grebes possess instead of fully webbed feet?Why is the extremely far back placement of grebe legs advantageous underwater?What is the core physical requirement for a grebe to successfully achieve airborne lift from a standstill?What surface must a grebe utilize to execute the running start needed for takeoff?What characteristic of grebes aids their superb diving ability by helping them submerge?Why do grebes generally exhibit a strong reluctance to fly when faced with a threat?What is the effect of the grebe's far-rearward leg positioning when it is on land?If a grebe is found grounded on land, what is often necessary before it can successfully fly again?How does the water launch mechanism allow the lobed feet to aid takeoff velocity?To which taxonomic order are grebes classified?