There's no single, universally accepted "intelligence scale" for animals. This is because intelligence is complex and can be measured in different ways. Different animals excel at different tasks, making it challenging to compare their cognitive abilities directly.

However, some animals often top lists of intelligent species:

1. Chimpanzees: Known for their problem-solving skills, tool use, and social complexity.

2. Dolphins: Show high levels of communication, self-awareness, and problem-solving abilities.

3. African Grey Parrots: Known for their impressive language skills and ability to understand abstract concepts.

4. Crows: Demonstrate sophisticated problem-solving, tool use, and social learning.

5. Pigs: Considered highly intelligent with good memories, problem-solving abilities, and social skills.

It's important to remember that this list is just a starting point and other species could easily be included depending on the criteria used to define intelligence.