The question of whether birds or mammals are more intelligent has long fascinated scientists and nature enthusiasts alike. Both classes of animals boast species with impressive cognitive abilities and complex social behaviors. However, quantifying intelligence across diverse species is notoriously difficult. This article will examine the evidence for advanced intelligence in birds and mammals and attempt to determine which group demonstrates greater general intelligence.
What is animal intelligence?
Animal intelligence refers to the variety of cognitive abilities present in non-human animals, such as learning, reasoning, problem-solving, memory, and language. However, intelligence is difficult to define and measure precisely in non-human animals because it manifests differently across species. Some key hallmarks of intelligence include:
- Capacity for learning and memory
- Ability to adapt behaviors and solve problems
- Awareness of self and others
- Communication skills
- Tool use
Any attempt to compare intelligence across species must consider differences in how these attributes emerge due to factors like environment, evolutionary requirements, and physical capabilities. Keeping this complexity in mind, let’s examine some of the evidence for advanced intelligence in birds and mammals.
Evidence of intelligence in birds
Birds possess many traits associated with intelligence. Songbirds like crows, jays, and parrots stand out for their impressive cognitive abilities.
Corvids
Corvids such as crows and jays are champion tool users and problem solvers. Wild New Caledonian crows craft complex tools from twigs and leaves to winkle grubs out of crevices. American crows bend wires to make hook tools to retrieve food. Corvids also display highly social behavior and impressive memory feats.
Parrots
Parrots have large brains relative to their body size and are capable of very advanced vocal learning. Some species like the African grey parrot can learn hundreds of vocalizations and demonstrate comprehension of shapes, colors, and numbers. Alex, a famous African grey, could identify 50 different objects and understand concepts like same/different.
Pigeons
Often maligned as “rats with wings,” pigeons have demonstrated surprising mental capabilities. In numerous studies, pigeons have shown they can discriminate individuals, learn abstract concepts and rules, and even perform basic math.
Tool use and problem solving
Tool use and problem-solving abilities provide key evidence of advanced intelligence in birds. Corvids and parrots are especially impressive tool users. New Caledonian crows join two sticks to make a longer stick and carve hooked tools out of tree branches. Woodpecker finches use cactus spines to extract insects. Green herons drop food, insects, or bait into the water to attract fish.
Social complexity
Complex social interactions also suggest higher intelligence in birds. Many parrots live in large social flocks and establish long-term pair bonds. Penguins use vocalizations to identify mates and chicks. Male bowerbirds construct elaborate displays to attract females. Complex communication and cooperation highlight birds’ cognitive sophistication.
Self-awareness
Self-awareness represents a major milestone in intelligence. Some research indicates birds may have this capability. Magpies can recognize their reflection in a mirror, suggesting self-recognition. Crows also showPerspective-takingPerspective-taking refers to the ability to perceive and understand a situation from another individual’s point of view. It is considered an important component of higher intelligence and social skills. There is some evidence that birds and mammals demonstrate perspective-taking abilities to varying degrees.
Evidence in birds
- Western scrub-jays adjust their caching behavior when competitors are around, suggesting they understand the visual perspective of others.
- African grey parrots take into account the knowledge state of human partners when communicating.
- Goffin cockatoos demonstrate the ability to infer what a human competitor can or cannot see.
Evidence in mammals
- Chimpanzees follow the gaze of conspecifics and humans, indicating shared attention skills.
- Dogs demonstrate theory of mind by interpreting human social cues to locate hidden food.
- Elephants take into account whether a human competitor can see them when trying to obtain out-of-reach food.
While the capacity seems present in both groups, perspective-taking may be more sophisticated in highly social mammals like primates. However, this is difficult to state conclusively.
Communication abilities
Communication is essential for cooperative intelligence. Humans prize our complex language abilities, but many other animals communicate in sophisticated ways.
Bird communication
Song learning in songbirds is critical for courtship and territorial defense. Parrots are renowned vocal mimics and some species can build vocabularies in the hundreds of words. Pigeon coos encode a surprising amount of information about identity and location.
Mammal communication
Vervet monkeys use distinct alarm calls to denote specific predators. Dolphins communicate identity using signature whistles. Honeybees perform complex “dances” to direct each other to nectar sources. While not a full language on par with humans, mammals do exhibit impressive communication abilities.
Direct intelligence comparisons
Directly comparing the cognitive abilities of birds and mammals poses challenges. However, some studies provide insight:
Delayed gratification
Tests of delayed gratification assess self-control and intelligence. Corvids and parrots match or outperform animals like chimps and capuchin monkeys at waiting for better rewards.
Insight problem-solving
Understanding causal relationships allows easier problem solving. Both birds and primates understand basics like object permanence and tool cause and effect. However, some corvids match great apes on tests requiring reasoning about physical causality.
Physical cognition
Judging object properties like weight and solidity requires intelligence. Birds rapidly make precise judgments about objects while primates learn these more slowly. This hints at differences in physical versus social intelligence.
Social learning
Imitating others provides a cognitive shortcut. Primates rely heavily on social learning compared to birds. For example, monkeys quickly learn to fear snakes by observing others while pigeons do not adopt the fear after witnessing reactions.
Brain structure comparisons
Examining brains provides another lens to compare avian and mammalian intelligence:
Forebrain size
The forebrain governs complex cognition. Relative to total brain size, birds have larger forebrains than mammals. The avian forebrain represents about 62% of total brain volume compared to 36% in primates.
Neural density
Packing more neurons into a brain region allows more complex information processing. Birds have greater neuronal density than mammals in both the forebrain and the pallium, suggesting greater computational capacity.
Connectivity
How neuronal pathways connect can enable intelligence. Bird brains boast many interconnected auditory regions. Recurrent pathways in the pallium may support advanced learning in birds.
Neurogenesis
Generating new neurons allows brains to reshape over time. Mammalian rates slow after maturity while songbirds maintain higher lifelong neurogenesis. This ongoing plasticity likely supports song learning.
Strengths of bird and mammal intelligence
| Bird Intelligence Strengths | Mammal Intelligence Strengths |
|---|---|
| Physical cognition | Social cognition |
| Tool use | Imitation learning |
| Spatial memory | Working memory |
| Reactive cognition | Planning abilities |
| Delayed gratification | Perspectice-taking |
This comparison highlights differences in the strengths of avian and mammalian cognition. Birds excel at physical problem-solving and spatial memory while mammals are adept at social learning and working memory. However, significant intelligence exists in both groups.
Conclusion
Based on the evidence, birds likely possess greater general intelligence compared to mammals. Corvids and parrots in particular demonstrate cognitive skills on par with or above most mammals. The large avian forebrain, densely packed with neurons and exceptional connectivity, seems to confer advantages for complex cognition. Birds’ expanded capacity for physical problem solving and memory provides an edge over the more social intelligence of mammals.
However, both taxa demonstrate sophisticated intelligence tailored to their ecological roles. Assigning superiority neglects how evolution selects different cognitive skills for each lineage. Overall, neither birds or mammals can claim the crown definitively in terms of general intelligence. Both groups reveal the amazing breadth and flexibility of intelligence possible through evolution.
