Bluebird on nesting box. Photo by D. Sillman
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The bluebirds at Harrison Hills Park are just starting to hatch their first round of nestlings. In two weeks, after an intense period of parental feeding and nurturing, these young birds will fledge and many of the parents, after a short rest, will start up their second clutch of the season. The new fledglings will then be mostly on their own and will have to solve some very fundamental problems of existence. Many of them won’t be able to accomplish these last steps in growing up quickly enough, and, so, will end up as a meal for a predator, or as road-kill, or as a window glass-kill, or as a fatality from some other random accident or event. In a good year about half of the fledglings don’t survive. The half that do, according to the logic of natural selection, are the smarter birds, the quicker learners, the more rapid reactors, or, maybe, and this isn’t really helpful genetically or evolutionarily, they are just lucky!
I have written about fledglings before: (Signs of Summer 4, June 7, 2017):
Robin fledgling. Photo by D. Sillman
“A robin with a juvenile speckled breast follows an adult around my concrete slab basketball court. You assume the adult is teaching the fledge how to find food, but the fledge seems to be staring off into space rather than watching what the adult is doing. The adult frequently finds worms and larvae and insects in the slab cracks of the court and instantly the fledge pops out of its mental fog and rushes up to the adult. She flutters her wings and chirps and puts her open beak an inch away from the adult. The adult stuffs whatever she has found into the fledgling’s mouth and then goes back to hunting. The fledge does not seem aware of the process, only the end result.”
And,
“A couple of weeks ago a fledgling crow (as large as the adult she was following but not quite as glossy black) showed up at the morning peanut and shelled corn feast out under my sunflower feeders. The fledge watched the adult crow and raised her wings and shook her head when the adult picked up a peanut or a piece of corn. That went on for several days until finally all of the morning crows were independently gathering their breakfast bits. The fledge still shows herself through the day, though, by lingering in the yard even when I step off the porch, or by not immediately flying to some high, safe perch when cars or dogs or cats cruise by. Breakfast was an easy lesson, there are many harder things that a young crow needs more days (and weeks) to learn. Two adult crows frantically chased off the sharp-shinned hawk yesterday afternoon. The crow fledge just stood out in the middle of the field agitated by all of noise but uncertain as what to do.”
And,
Carolina wren. Photo by D. Sillman
“A Carolina wren and her fledge are chipping loudly in the lower branches of the arbor vitae. They are being incredibly conspicuous in a zone frequently prowled by the neighborhood cats! The fledge, though, can’t seem to keep her volume down when the parental bird is in sight! I have watched the adult stick her beak into the open beak of the fledge. I can only imagine the tasty mix of branch gleaned insects and larvae! The adult immediately moves up to higher branches to keep hunting. The fledge sits down low, in the danger zone, waiting for more. Later the wren and the fledge join us on the deck. The fledge sits on the surrounding rail like a Christmas ornament while the adult frets and fusses.”
These three observations of fledglings highlight several important features of this age class of birds: the fledglings don’t know how to find their own food, they are predator naïve and unaware of dangers around them, they learn certain survival skills faster than others, they have a tunnel-view of the world and they are primarily focused on and aware of themselves and their own needs.
I have recently finished a book that some good friends gave me this winter that discussed the wide range of adolescence and its transition into adulthood. The book is called Wildhood: The Epic Journey from adolescence to adulthood in Humans and Other Animals by Barbara Natterson-Horowitz and Kathryn Bowers. Wildhood outlines four primary learning tasks for animals transitioning into adulthood, and we see the first two or three of these in our young birds:
- They have to learn to leave the nest and take care of themselves
- They have to learn how to stay safe
- They have to learn how to navigate social hierarchies
- They have to learn how to communicate sexually
The examples the authors’ use to highlight their points mix human and non-human animal experiences and scenarios. The human examples were quite illuminating both as a self-reflection of my own growing and maturation experiences (THAT’s why I felt that way! THAT’s why I did all of those stupid things!) and also to appreciate my own children’s growth and maturation periods.
Spotted hyena. Photo by C.J.Sharp, Wikimedia Commons
Two quick points about the human “wildhood” before we jump into the world of hyenas, sea otters and king penguins: the “teenage brain” is very active in storing away memories. The “teen years” (extending into the 20’s) is the time of critical life experiences (often cast in the form of stresses and humiliations) that help us deeply learn the four tasks required for survival. These memories stay with us for our entire lives and often return to us in waking reveries and dreams.
The “teenage brain” that is creating these vivid, lasting memories is also undergoing a dramatic shift in its circadian rhythm pattern to move sleep cycles later and later into the night. This shift causes young people to become, as one of my old office mates used to say in reference to her own, college-aged children, “night-dwelling vampires!” Most of us remember regularly staying up with friends on weekends in high school or in our dorm rooms in college to 2 or 3 in the morning. Most of us also remember sleeping in in our dorms right through 8 am, 9 am or even 10 am classes. Matthew Walker in his book Why We Sleep discusses this phenomenon of adolescent sleep shifting to intervals that are radically different from their parents or younger siblings. He feels that this is part of the evolutionary process of separation of adolescents from the parental group. Tasks #3 and #4 in our Wildhood learning program are better accomplished when the adolescents are clustered together away from the watchful eyes of their parents.
Anyway, the human parts of Wildhood were interesting and triggered lots of memories, but it was the discussions of the paths from childhood to adulthood in sea otters and hyenas and king penguins that I enjoyed the most. Their perils were more far more serious than mine ever were. They faced gauntlets of great white sharks, or lions and rampaging adult hyenas, or leopard seals and killer whales that were much more perilous and potentially deadly than the stresses of having to give a speech in front at some assembly, or playing a solo at an orchestra concert, or making a free throw in front of a gym full of screaming people, or asking a girl to go out on a date.
King penguin. Photo by A.Shiva, Wikimedia Commons
How did these young, totally clueless animals survive? Each of them dove into, ran into or were born into direct contacts with their waiting predators and tormentors. They didn’t know any better and were energized by the adolescent, impulsive desire for new experiences and challenges. Surviving the initial encounters made them instantly wiser and more cautious and afterwards, as they interacted with their fellow surviving adolescents, helped them to build a support and information network that assisted their predator awareness, food gathering techniques and, eventually, their social and sexual communication skills. The lessons were harsh and failure often meant death, but lessons were learned quickly and well.
There was a lot of information in the Wildhood book. Terms like “puppy license” (a wide range of behaviors tolerated by adults of a species in very young individuals), “ephebiphobia” (fear or dislike of youth (often seen in the older individuals of a species just after a “puppy license” expires!)), “dominance hierarchy” (a social hierarchy based on force), “prestige hierarchy” (a social hierarchy based on skills), and “niche picking” (an individual finding a social spot where their skills or traits are valued. Niche picking is often the transition point from a dominance to a prestige hierarchy (for humans, this might be somewhere between middle school and college!).
The authors also described in great detail the phases a predator goes through in finding, assessing, attacking and killing their prey, and listed ways that a potential prey individual, as it becomes more and more experienced, could resist or deflect the process of predation. They went through these phases from the point of view of a moth being stalked by a predatory bat. They then abruptly flipped the predator scenario into that of a human, middle school bully, and applied their ideas to the avoidance of being bullied (their best practice summary: “just don’t look too weird!”).
I don’t know of anyone who wants to return to their own adolescence, but it is very interesting to see it played out in so many different organisms!