He read of the eerie morning of August 18th, 1961, when residents of Capitola, California, a smaller community on the coast of Monterey Bay, awoke to a frightening discovery. Droves of sooty shearwaters, a medium sized seabird native to the area, were acting erratically. Some crashed into rooftops, windows, and cars. Others flopped, dying in the streets, while more vomited their fish dinners into the grass. It was a short incident, but one that terrified and traumatized those who had witnessed this mass bird hysteria. Desperate to find an answer for this sudden behavior change of the seabirds, scientists hypothesized that domoic acid poisoning could be to blame. This was never proven, but it is a viable suggestion. Domoic acid is a neurotoxin produced by algae. These algae can then accumulate in shellfish, sardines, and anchovies. When animals or humans ingest this toxin, which was ingested by the shellfish, their brain is affected, causing seizures and even death. “Domoic acid is a tricarboxylic amino acid that is classified as an excitatory amino acid (along with the dicarboxylic amino acids glutamic acid and aspartic acid). It acts through the inotropic non-NMDA receptor and especially affects the hippocampus and amygdala of the brain. The time from ingestion to intoxication can range from minutes to hours.”2 Seabirds would undoubtedly be susceptible to this type of poisoning, and the description of the event in August of 1961 mirrors the listed animal symptoms of domoic acid poisoning: head weaving, seizures, bulging eyes, mucus from the mouth, disorientation, and death. In 1991, domoic acid was the official cause of death for hundreds of brown pelicans and cormorants in Monterey Bay, on the same beaches the peculiar bird activity had played out exactly thirty years earlier. A bird attack in 2006 was also attributed to domoic acid poisoning when a brown pelican burst through the windshield of a moving car on the Pacific Coast Highway.
Domoic acid structural formula.
Unfortunately, humans have also been victim to this poisoning. The most dramatic case occurred in 1987. Over one hundred people in Eastern Canada fell ill after ingesting mussels fished from the coast of Prince Edward Island. They described a number of symptoms including nausea, vomiting, severe headache, and most alarming, loss of memory. This amnesia, for some, was permanent. At the time, the doctors called this phenomenon “amnesic shellfish poisoning.” Three of the sufferers died from this painful syndrome caused by domoic acid. In 1991, two months after the bird deaths in California, two dozen people were struck ill with amnesic shellfish poisoning, or domoic acid poisoning, in Washington State. They had all consumed razor clams seized from the coasts of Oregon and Washington. When testing was done after the incident, it was also found that Dungeness crabs in the area were rife with domoic acid. Though human incidents of amnesic shellfish poisoning are rare, according to the Channel Islands Marine and Wildlife Institute, animal incidents seem to be on the rise.
It is generally accepted that the incidence of problems associated with toxic algae is increasing. Possible reasons to explain this increase include natural mechanisms of species dispersal (currents and tides) to a host of human-related phenomena such as nutrient enrichment (agricultural runoff), climate shifts or transport of algae species via ship ballast water.3
Birds are not only susceptible to domoic acid; they have also been documented as acting erratically while “drunk.” In the fall of 2018, Gilbert, a tiny town in Minnesota (which also happens to be the hometown of Meg’s in-laws), was thrust into the national spotlight thanks to a drove of drunken birds. Residents began to complain about robins and other small birds crashing through windows, falling out of trees, and hitting cars. While not as dramatic as the seabirds on the coast, these small species caused confusion in the Minnesotan community. There is some dissension on the cause. Gilbert Police Chief Ty Techar explained that some had got a little more “tipsy than normal.” This can be caused by fermented berries, which due to the early frost in Minnesota, may have become more potent. Kenn Kaufman, field editor of Audubon, said “drunken birds were certainly a real phenomenon. Apart from berry eaters, drunkenness can also befall yellow-bellied sapsuckers that feed on fermented tree sap.”4 But other experts reject the notion that the birds in Gilbert were inebriated, suggesting that the robins were frantically attempting to leave town at the sight of hawks, who were migrating at that time. Whatever the cause of the strange behavior, it is safe to conclude that birds can become more than just innocuous background noise in sudden, brutal encounters.
Although he’d read the scientists’ hypothesis of domoic acid poisoning in the 1961 Capitola incident, Alfred Hitchcock chose not to include any sort of scientific explanation in The Birds. The master of suspense knew that the mystery of the unknown was much scarier than any seaborne toxin. Also, in reality, the birds off the coast of Monterey Bay hadn’t purposely attacked humans. This, once more, prompts the notion of anthropomorphism in the development of animal movie monsters. The birds in The Birds had to have a maliciousness in order to terrify. They are depicted as waiting patiently before an orchestrated attack on schoolteacher Annie Hayworth (Suzanne Pleshette) and her students. This happens in great effect during the diner scene, too, as the birds work to cause chaos. Which led us to question the intelligence of birds and their ability to work together, whether for productive or nefarious means.
Generalizing all birds would be a naive practice, as they range greatly in size, lifestyle, and therefore intelligence. We will focus on crows, as their mental acumen is of great scientific interest. In recent years, corvids (crows, ravens, rooks, and jays) have been praised for their rather impressive smarts. (They are also a pervading symbol of horror, thanks not only to Hitchcock, but also to Edgar Allan Poe’s haunting 1845 poem “The Raven.”) Studies have proven that they utilize tools, problem solve, and can consider future outcomes. Crows in Japan figured out that carefully placing nuts on the street led to cars crushing the hard shells. They were then observed making note of traffic lights before retrieving the opened nuts while vehicles idled.
Scientists contend that corvids are as intelligent as apes. They exhibit traits that were long believed to be only attributed to primates (as well as dogs and dolphins). These include recognizing themselves in a mirror, reasoning out complex problems, and using and understanding a symbol system. Researchers from the University of Iowa along with contemporaries at Lomonosov Moscow State University proved that crows could understand symbols by their ability to match like-pairs:
To reach that conclusion, the scientists trained crows to recognize whether two objects were identical or different, which the birds indicated by pressing one button when shown pictures of objects that matched and a different button when the objects didn’t match. Once all the birds were good at matching objects, researchers showed the crows images of pairs of objects. Some images depicted matched pairs, while others depicted two mismatched objects with different shapes or colors. In response, crows could press buttons to choose between a matched pair or a mismatched pair.5
Fascinatingly, corvids also have a measure of social intelligence that comes to us humans in later childhood. It is termed “theory of mind,” the concept of recognizing that others have similar but different thoughts, and then applying this knowledge to change one’s own behavior. An example would be when ravens believe a human has spotted them in the act of hiding food. They will alter their hiding spot as a result, choosing to obscure it better, as they can predict that another entity would want to steal their goodies. Crows were chosen to be the birds perched on the playground equipment in The Birds. A crackling sea of black wings, they can elicit fear in anyone, not just ornithophobes. So, do they use this power of intellect to hurt humans? Why would they?