Crow

Smarter than they look

Crows are among the most cognitively advanced animals studied — comparing favorably with great apes on certain tasks despite a brain just 1/100 the size. Documented abilities include:

• Causal reasoning — solving multi-step puzzles where each step’s solution must be inferred from the next.
• Tool use and tool manufacture — bending wires into hooks (New Caledonian crows are the famous example, but American crows do similar things).
• Self-recognition in mirrors (varied results across species).
• Counting — discriminating up to about 7 items.
• Future planning — caching food in locations they remember to return to weeks or months later.

The corvid brain has a structure called the nidopallium caudolaterale that performs functions analogous to the mammalian prefrontal cortex — allowing for complex cognition without the large primate-style cortex.

They remember faces

In a famous experiment by John Marzluff at the University of Washington, researchers wearing caveman masks captured and banded crows, then released them. For years afterward, the same crows scolded and harassed anyone wearing the caveman mask — even people who had never trapped them. The behavior persisted for over a decade and spread through crow social networks: young crows born after the original capture also scolded the mask, learned from their parents.

Crows recognize specific human faces, remember individual humans for years, and pass that recognition along to other crows. People who feed crows in their backyard often acquire a small loyal following. People who shoo crows away from a garden may find themselves dive-bombed.

Family groups

American crows live in extended family groups that often span generations. Young crows typically stay with their parents for several years before founding their own families, helping raise younger siblings in the meantime. A breeding pair often has 2–3 helper offspring at the nest each year.

This structure — cooperative breeding — is rare in birds and an indicator of complex social cognition.

Roosting in tens of thousands

In winter, American crows form massive communal roosts — sometimes 100,000+ birds in a single tree-cluster, descending each evening from feeding grounds spread across hundreds of square kilometers. The largest roosts are concentrated in cities (where heat-island warming and security from owl predators are advantages) and at agricultural sites with abundant winter food.

Many cities have unsuccessfully tried to disperse crow roosts with noise, lights, and other harassment. Crows respond by adapting to the harassment and continuing to roost.

Crow funerals

Crows display unusual behavior around their dead. When a crow dies, other crows gather around the body, often calling and behaving differently than normal. Researchers debate whether this is grief, information-gathering (“what killed this one?”), or social bonding — but the behavior is consistent enough to be studied across populations.

A long history with humans

Corvids have been associated with humans across many cultures — sometimes as omens of death and bad luck, sometimes as messengers and tricksters. The Norse gods Hugin and Munin (raven companions of Odin) are emblematic; Native American Pacific Northwest stories cast Raven as a creator-trickster. The gathering of crows around deathbeds in folklore probably reflects the real behavior of crows attending to recently-dead bodies.