COVID is a pandemic disease, Corvid is a family of birds of quite high intelligence. In terms of the brain to body weight ratio, they are intermediate between great apes and humans. Corvids are globally distributed and include crows, magpies, Jays, and others. The family Corvidae includes the genus Corvus – crows and their larger cousins the ravens.
Here in Arkansas, we have two the American crow and the slightly smaller and less numerous Fish crow. When you see a large group of crows, called a murder of crows it is most likely the American crow. Crows, like other birds are more often heard than seen, so it is good to learn their calls. The more numerous American crow is often heard in groups with lots of “caws” at once. The fish crow is more likely to be heard singly with a sort of nasal sounding cah or cah-hah, as it it is laughing at you.
Their intelligence is shown in their diet. Crows are quite adaptable omnivores. They can make a living by a number of means, from roadkill to any number of crops and stored foodstuffs, hence they are notable agricultural pests. Even though they are counted as migratory birds and therefore have some federal protection, they can be hunted in Arkansas (September through February.) Possibly the second most intelligent animal on the planet can be hunted with no bag limits.
A broad range of tests shows the intelligence of crows, tests that require recognizing analogies. Tests that involve not just the use of tools, but the fabrication of tools specific to a particular task. Tests that require multiple steps. Tests that require facial (human) recognition. Examples abound.
A test of the ability to recognize analogies, similarity versus dissimilarity went like this: A crow was shown a picture of two symbols, similar such as two circles, or dissimilar, a circle and a cross. They were given two options for a food reward, either two similar symbols, two squares or dissimilar symbols, an oval and a star. They had to recognize analogous pairs, and they did so on the first try, no training needed. If they were shown a dissimilar pair, the food reward was indicated by another dissimilar pair but of different objects.
Tool fashioning was tested by requiring the crow to modify an object to become a useful tool. One test required a hook-like object to retrieve a reward. They were presented with several items including a piece of wire. Again with no training, they were able to figure out that the wire could be bent into a hook and use it to retrieve the reward.
Facial recognition was tested over a three year period. Students on campus wore a particular mask while capturing crows for banding. Over the next three years in the study, when the banded crows saw anyone wearing the same mask they aggressively mobbed the masked person, even if that person was in a crowd. The banded crows were also able to recruit crows that had not been banded and hence had no reason to see the masked person as a threat. The moral of the story – crows are really smart and they can hold a grudge, for years.
Dr. Bob Allen is Emeritus Professor of Chemistry, Arkansas Tech University.