Explanation:

Water Birds:
Cranes and herons are categorized as water birds. Water birds are a group of birds that are adapted for living near or on bodies of water. These birds have various adaptations that allow them to thrive in aquatic environments.

Wading Birds:
More specifically, cranes and herons are classified as wading birds. Wading birds are a type of water bird that have long legs and long necks, which enable them to wade through shallow water in search of food. They are commonly found in wetlands, marshes, and other aquatic habitats.

Long Legs and Spread-out Toes:
Cranes and herons have long legs with spread-out toes, which are important adaptations for their wading lifestyle. Here's why:

- Long legs: The long legs of cranes and herons allow them to wade through water without getting their bodies wet. This is advantageous because it helps them avoid getting weighed down by water and allows them to move more easily through aquatic environments.

- Spread-out toes: The spread-out toes of cranes and herons provide them with better stability and balance while walking on uneven and sometimes slippery surfaces such as mud or vegetation. This adaptation helps them navigate their wetland habitats and allows them to stand still for long periods of time while waiting for prey.

Other Categorizations:
Although cranes and herons are primarily classified as water birds and wading birds, they can also be categorized in other ways:

- Flying birds: Cranes and herons are indeed flying birds as they have wings and are capable of flight. However, this categorization is not specific to cranes and herons alone, as all birds are capable of flight.

- Perching birds: Perching birds, also known as passerines, are a large group of birds that have specialized feet and toes for perching on branches and other surfaces. Cranes and herons do not have these specialized feet and are therefore not considered perching birds.

In conclusion, cranes and herons are categorized as water birds, specifically wading birds, due to their adaptations for wading through water such as long legs and spread-out toes.