Hi,
You mention the scooter which must have limitations for movement for panning or capturing action that might happen suddenly behind you. With this in mind you could see if it was reasonable to get a monopod (like a tripod but with only one leg ) that could be easily clamped or screwed onto the frame or footplate of the scooter. thus allowing you to maintain a comfortable camera position without tiring your arms.
If you use a longer lens they will tend to have a smaller minimum f-stop (i.e f5 rather than f3.5) this means you will be getting less light through the lens. It always rains when I go to the zoo so too much light isn’t a problem