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It is hard to miss the California Scrub Jay. As I watch it alight on a branch, it announces its presence with a loud, raucous squawk. Emily Dickinson called them “blue terriers” for their bark- like call. Not quite on par with other songbirds! It was hopping in bold lunges, pumping its tail and looking around with quick twists of the head. Charging through the branches as if sprinting down a path, it scared other birds away with an aggressive and purposeful energy. The California Scrub Jay compensates it’s belligerent stance and lack of melodious call with a striking appearance. They are handsome birds with azure blue wings, tail and head, with light gray underparts and a distinctive white throat and eyebrow. Its feathers are not actually blue! The bright sapphire color we see is in fact, the result of the unique inner structure of the feathers, which distorts the reflection of light off the bird, making it appear blue. If that structure were to be damaged by crushing the feathers, the blue color would go away. The pigment in their feathers is melanin, which is brown. The blue color is caused by light dispersed through modified cells on the surface of the feather barbs. One of the important characteristics of the California Scrub Jay is their “caching behavior”. As scrub jays spend their day foraging for seeds and acorns, they hoard their stash in little piles all over their territory in order to ensure supplies when food is scarce. Rather than building up one big pile, jays hide their bounty in many smaller piles. This strategy is called “scatter-hoarding” and leads to jays amassing up to 200 caches within their home ranges, which average about 1/10 of a square mile. Scrub jays must have excellent spatial memories just to remember where they have stockpiled all these future snacks. This is a rather impressive task. I wonder whether anyone can remember the last 200 places they ate at?! Since the hippocampus is the part of the brain that is involved in memory formation and storage, researchers have speculated if scrub jays have particularly large hippocampi, given all this remembering that they must do. Turns out that scrub jays do have one of the largest hippocampus sizes compared to their body size. The important factor is not absolute brain size but brain size relative to body weight, often termed as the “encephalization quotient.” The size of the hippocampus also comes in handy when the California Scrub Jay wants to plan ahead. This is important because they store not only nuts and seeds but fruit, insects and worms, foods that perish at different rates. Cached insects can spoil in days if the temperatures are high enough, while nuts and seeds can last for months. A series of creative experiments by Nicola Clayton and her team at Cambridge University showed that the birds retrieve the more perishable food before it rots, leaving the nonperishables, such as nuts and seeds, until later. The jays use their experience of how quickly food degrades to guide their choice in recovering their caches. Remembering that perishable food items may need to be retrieved sooner requires recalling cache locations, cache contents, and the time of caching. This ability to remember the what, where, and when of specific past events is thought to be akin to human episodic memory, the remarkable capacity to remember specific personal experiences. Like us, the birds seem to be using events that happened in the past (what they buried when) to figure out what to do now or in the future (dig up or save until later). Besides their remarkable memory, scrub jays also seem to have a social awareness that they employ for more deceptive purposes. Scrub jays often cache in a secretive manner to protect their stores from other birds, hiding behind objects, or relying on shade to obscure them from other birds’ view. Sometimes though, these efforts are not enough. If jays “believe” another bird is watching them cache, they will return to the cache later and “re-cache” it to a new secret location so that their food cannot be stolen. To do this, the jays must be able to “understand” in some way that the other birds are not only able to see what they are doing but also use that information to preserve their hard-earned seeds. This requires a social skill called ‘theory of mind’. Theory of mind involves the ability to understand what other individuals know. Simply put, it is the ability to realize that another bird is watching its cache with an intent to steal it, and that hiding that snack in a new location could trick the other and protect the food. The capacity to take the perspective of the other and to grasp what might be going on in another creature’s mind is one of the hallmarks of theory of mind. Theory of mind may sound basic, but it is a demanding and complex social ability that even humans struggle with. A human infant may not develop theory of mind until around four years of age. Hence, claiming jays have this ability has literally ruffled feathers among biologists and psychologists alike. Some have suggested that this might just be an example of social learning, when birds find from trial and error that not moving your food can lead to unfortunate consequences. Yet another astonishing fact about this Machiavellian tactical caching behavior is that a California Scrub Jay will resort to these clever tactics, only if it had its own experience in stealing from others. Birds that have never pilfered themselves hardly ever recache. In other words, “it takes a thief to know a thief!” Scrub jays are also among the most social of birds. They participate in cooperative breeding, when they share the responsibility of raising the young. These brainy birds also watch out for each other while foraging and feeding in groups. They post a sentinel, or lookout, and take turns watching for predators, enabling the other members of the flock to forage with greater concentration and less danger of being captured by a predator. There has been a lingering question as to whether birds experience human social or emotional capacities such as grief. For example, it has been observed that once the California Scrub Jays spot a dead member of their flock, they make loud alarm calls to draw the attention of others. The other jays then stop foraging and congregate near the dead bird and some remain close to the dead bird even for a day or two. Were they mourning a fallen member of the jay tribe? Or were they just demonstrating how birds respond to a dead member of their own species, by noisily telling other birds about the death and perhaps alerting the group to danger, a behavior that is often termed as “cacophonous aggregation”. It is imperative that we are cautious while imputing human emotions like grief to other species. It is very easy to slip into the anthropomorphic trap! But what is so remarkable is that the California Scrub Jays are capable of some form of metacognition. Many such abilities and skills have been outlined by Jennifer Ackerman in her masterly tome, Genius of Birds. Thus, to call someone “bird-brained” is inaccurate and an unfortunate insult to the avian species! On an altogether different note, it seems timely to recall the classical song, Bird Brain by the inimitable Alan Ginsberg. It is a six and half minute song recorded with a Denver based group called The Guons. It starts with these scathing lines; “Birdbrain runs the world Birdbrain is the ultimate product of Capitalism…” Not too inappropriate in these times…. PS: You might wonder why I called this bird perspicacious and not just brainy. Perspicacious is somewhat similar to being shrewd or astute. But there is a subtle difference. All three mean acute in perception and sound in judgment, but ‘shrewd’ stresses practical, hardheaded cleverness, whereas ‘perspicacious’ implies unusual power to see through and comprehend what is puzzling or hidden. And ‘astute’ suggests both shrewdness and perspicacity combined with diplomatic skill. The ability to quickly pick out from among the many things, those that are significant and to synthesize these observations and develop a practical strategy is what is characteristic of being perspicacious and the California Scrub Jay symbolizes it. A skill that many a psychotherapist will be envious of! GLIMPSES OF THE CALIFORNIA SCRUB JAYS AT: photos.app.goo.gl/YSD1BrtiBEFmp7GL7 KINDLY POST YOUR COMMENTS HERE AND NOT IN GOOGLE PHOTOS!
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 The moments I spend in the backyard are a gateway from the outer world to the inner. Often, I am lost amidst the chirping of the birds and the pranks of the squirrel that ambles along the fig tree in search of a ripe fruit. When one is immersed in the sounds and sights of the natural world, one is in touch with something deep and indescribable. Nature reveals it’s beauty in inexplicable ways..
During one such moment, my attention was drawn to a dainty butterfly darting across the garden. It was wafting lazily over the grass. The morning sunlight reflected off its wings and it seemed to disappear and reappear under its shadows. When it perched itself on top of the broccoli plant, I had a long look at it. I was charmed by its fluffy white body and powdery white wings with the smoky black-tinged edges. When I checked the net, I discovered that this delicate winged beauty is known as the Cabbage White Butterfly. The cabbage white butterfly is often the first butterfly to appear at the beginning of summer. It is affectionately called the “summer snowflake” and there is an interesting history tucked into its gossamer wings. The cabbage white was introduced to the eastern United States and southern Canada along with European cabbage imports in the 1860s. It’s less clear how this species arrived in California. There are no documented appearances in San Francisco before the 1880s, though the butterflies were flourishing in the city by the time of the 1906 earthquake. One Gold Rush-era specimen from Yreka suggests they might have arrived with the Spanish explorers in the Mission period. When food shortages gripped the United States during World War II, the country launched a “Dig for Victory” campaign that resulted in more than 20 million “victory gardens” in backyards and public parks and the harvest of more than 8 million tons of fruits and vegetables. The most popular produce in these gardens were cabbage, kale, broccoli, kohlrabi, turnips, and Brussels sprouts—all plants from the cabbage family. And among those who ate most heartily from the victory gardens was the caterpillar of the small white butterfly - Pieris rapae or the cabbage white. Cabbage whites ate so many victory crops in the United States and in England that one British newspaper called for exterminating these butterflies on sight, calling them “Hitler’s ally”! People still refer to the cabbage white as “rat butterfly,” and a “weedy” species—but their extermination never happened. An incredibly rapid spreader, it has survived all efforts at its annihilation! How did this diminutive butterfly succeed in surviving in different environments across time? Surely it must have worked out ways of working through climate change. It has been suggested that it adapts to climate change by producing less dark pigment so that it absorbs less heat from the sun to avoid overheating in warm climates. One of the researchers involved in this enquiry is Art Shapiro who is a distinguished professor at University of California-Davis. For decades, he has been offering a pitcher of beer to the person who brings him the first cabbage white of the year in the Davis-Sacramento area! But there’s more to the cabbage white than meets the eye. A butterfly relies on the sun’s warmth to heat up its flight muscles before it can flutter off. But it has been observed that even on cloudy days the cabbage white butterfly takes flight before other butterflies. This got the attention of scientists at the University of Exeter, England. They noticed that the cabbage white butterfly is distinctly different from the other butterflies in that it poses in a V-shape. This posture concentrates solar energy directly onto its flight muscles in the thorax, warming them up for takeoff. Inspired by this, they further examined whether the solar panels could be made more effective by replicating the butterfly’s V-shaped pose. Not surprisingly, they found that the amount of power produced increased by almost 50 percent! They also noticed that the surface of the butterfly’s wing is highly reflective. By imitating the V-shaped pose and the reflective wing structure, the researchers produced lighter and more efficient solar panels. These results suggest that the ordinary cabbage white butterfly is an amazing expert at harvesting solar energy! The cabbage white’s white wings also reflect ultraviolet light, which we can’t see but the butterflies can. To our eyes the butterflies seem plain and drab, but to each other, females are a gentle lavender and males shine with a deep royal purple. I marvel at this humble creature, imagining the rainbow it sees that I am unable to. Nature is valuable not just because it is beautiful. It possesses intrinsic value, grounded in its intelligible structure which we to strive to unravel. Let us continue to be awe-struck and feel inspired by the intricate mysteries of the environment that we are enveloped in. Each wing an albino leaf Smudged with charcoal At the tip Flitting here and there Basking in the sun What tales you can share About your seventeen degrees? LOOK FORWARD TO YOUR COMMENTS . . . |
Dr Raguram
Someone who keeps exploring beyond the boundaries of everyday life to savor and share those unforgettable moments.... Archives
May 2024
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