This semester, I am taking “Human Evolution,” a fascinating course taught by Andrew Hill. As I learn about the complex web of human ancestors and relatives (with multiple hominid species coexisting and even preying upon each other!), I find myself wondering where exactly one can draw the line between humans and animals. We think we know humans are unique, but attempts to define our uniqueness have fallen, one by one, like dominoes flicked contemptuously aside by Mother Nature.

Thus, bear with me as I step back from our discussions about Sex Week and nuclear disarmament to bring us all back to what is really important: birds.

Two summers ago, I worked as an intern at the National Aviary, home to over 200 species of birds. During my time there, I could not help but be impressed by the many complex bird personalities and behaviors that challenged traditional distinctions between humans and animals. Perhaps the most notable of these was the tale of Sahara and the Ice.

One hot and humid Wednesday, I was cleaning an owl enclosure across from Sahara, a juvenile Southern Ground Hornbill. To picture Sahara, imagine a large, ground-bound Zazu. Like Zazu, Sahara loves to talk; she squawks loudly and constantly for a human audience. I, however, apparently did not qualify as human, perhaps because my features were completely obscured by sweat, dirt and other unmentionables as I chipped away at accumulated owl droppings — in any event, Sahara kept mostly quiet, although she did alert me to the approach of other trainers by a Doppler effect of squawks as they passed by.

At one point, Sahara’s squawks remained high-pitched and excited for longer than usual, so I straightened up to see a trainer named Mike dumping a huge bucket of ice in one corner of her enclosure. Mike turned to me, winking as he tucked the empty bucket under one arm, and cheerily remarked, “Enrichment!” before strolling away. The trainers regularly introduce toys and other novelties to the birds to keep them happy and interested in the world around them.

While I was, of course, completely captivated by the enticing task at hand, I found myself distracted by Sahara’s antics with the ice. She first explored this unusual addition to her home by cautiously stepping on it, then leapt backward in comical confusion. Next, she tried delicately picking up pieces of ice in her ponderous beak only to quickly drop them.

But finally, Sahara did something strange. She picked up a strip of lukewarm meat from her dish, strode purposefully to the pile of ice and carefully placed the strip in the center of the ice. I watched, fascinated, as she repeated this procedure for four more pieces of meat, fussing with the arrangement to keep the pieces evenly spaced. After about 10 minutes of puttering around her enclosure, Sahara returned to the ice pile, cocked her head with a squawk and eagerly gobbled up all four nicely chilled meat strips.

Sahara, a bird with no experience with ice (and most likely with no ice-related genetic background from her South African forebears), seemed clearly to use ice as an impromptu refrigerator.

Is it a logical fallacy — anthropomorphism — to assume that human-like behavior implies the existence of human-like mental processes? Well, what do you call it when someone assumes that complex human-like behavior is NOT evidence of complex human-like mental processes? I call it the biological equivalent of the Ptolemaic model of the solar system.

My experiences strongly suggest that animals have distinct personalities and emotions; many species use tools, plan for the future, solve puzzles, have complex cultures, communicate with something approaching language, appreciate aesthetic beauty, farm plants and fellow animals and exhibit other traits once thought to be distinctly human.

For example, an early marine center in Florida housed a killer whale couple which finally became pregnant after many unsuccessful tries. About 11 months into the pregnancy, the father — as was customary for him — ran his nose along the mother’s belly, emitting high-frequency clicks. Suddenly he froze in the water, then swam pell-mell against the side of the pool, repeatedly smashing his head against the wall, and later became apathetic and melancholy. After a few days, their baby emerged stillborn.

The best explanation is sort of amazing: The killer whale father performed regular sonograms to check on his baby, realized it was no longer alive and sank into self-destructive depression.

Sure, we can think abstractly and communicate with a complex, nuanced language, two relatively clear differences between us and our nonhuman neighbors. But consider Sahara; consider the bereaved killer whale father. Humans are not separated from animals by a clear, bold line. Rather, we are just a relatively advanced point on a long and complex continuum.

Dakota McCoy is a junior in Branford College. Contact her at