Green-rumped parrotlets learn their "names" through their parents

I wanted to share this very interesting study on green-rumped parrotlets showing that chicks learn their names from their parents in much the same way that human infants learn how speak from their human parents. Shown above is a still from a video camera placed in the parrotlets' nests to observe the interactions between chicks and parents.

Karl Berg and his team then at Cornell and now at UC Berkeley set up 106 artificial nesting boxes with hidden cameras and observed many generations of green-rumped parrotlets in Venezuela for 24 years. Green-rumped parrotlets, like other parrots, use contact calls that are unique to each individual parrot and function much like names.

Berg's team wondered whether these calls were innate (known from birth without learning) or learned from their parents. They switched parrotlet eggs between 12 unrelated breeding pairs of parents and compared the calls of these chicks to those of chicks that grew up with their biological parents. If the parrotlet's contact call is innate, the chicks that were switched should develop calls that are similar to their biological, not surrogate parents. If the calls are learned, the switched chicks should develop calls that are similar to those of the surrogate parents.

Guess what - the calls are learned! Check out the video below:

The process works something like this: momma parrotlet's name is Lucy. Daddy parrotlet's name is Jeff. The chicks use these names as templates and modify them slightly to transform them into their own unique names. So the chicks of Lucy and Jeff might have names like Lucille, Jeffron, Lucifer, Jeffers and so forth. It is especially important for the young fledglings to be distinguishable because right after they leave the nest they still need to be fed by their parents. The parents use the contact calls to find their fledglings among many, many birds in a flock. In previous work, parrots have been observed using contact calls while flying to keep an ear on each other.

Parrots are known to be lifelong vocal learners just like us, but this study demonstrates that parrots actually teach something like a language to their offspring. Pretty neat huh?

Alex the African Grey

My love affair with birds and their intelligence really begins with Alex the African Grey. If you don't know who I'm talking about, I must ask what kind of gigantic rock you've been living under. 

Here he is - the precocious bugger - distinguishing shape, color and material with his human, researcher Irene Pepperberg, adjunct professor at Brandeis and lecturer at Harvard University. 

Alex, like all other African Grey parrots, is a master of vocal mimicry. Words, phrases, songs, cell phone noises, the kitchen sink, the neighbor's dog - you name it and the African Grey will mimic it. What makes Alex special is that he was trained for 30 years by Pepperberg and her team to use human language so that they were able to probe the limits of his cognitive capabilities. 

For a great introduction to Alex and Irene's work, here is a short NOVA Science Now clip:

Pepperberg estimates Alex to have the cognitive capacity of a five-year-old human child and animal intelligence rivaling that of dolphins and great apes. By 1999 he could already recognize and distinguish 50 different objects, recognize quantities up to 6, categories objects as "same" or "different" and had a vocabulary of over 100 words. What is truly remarkable about Alex is not the number of words he could use or objects he could recognize but that he really seemed to understand what he was saying. 

He recognized that a key was a key no matter if it were big or small, grey or yellow. He used short phrases to request food items he wanted and to be taken somewhere else like outside or back to his cage. When asked the difference between two identical objects, he responded "none", which indicates an understanding of zero or nothing. 

What I find most impressive about Alex's cognitive abilities is not that he was capable of simple arithmetic (!) but that he understood some basic rules of syntax in the English language. Alex used different personal pronouns when referring to himself or others and most impressively, was able to combine words already in his vocabulary to refer to objects he had never seen or been taught the name of before. Before Alex knew what an apple was, he referred to it as a "banerry", what a linguist friend of Pepperberg's thought was a combination of banana and cherry, words (and fruits) he already knew. When Alex had his first taste of birthday cake, he called it "yummy bread", using the adjective "yummy" to correctly modify the noun "bread". 

From a neuroscientist's perspective this is really remarkable when one considers how different avian brains are from the brains of other classically intelligent species. Many scientists argue that humans are as smart as they are because of the folds in their brains (the gyri and sulci) that the maximize surface area to volume ratio. Interestingly, dolphin brains have even more folding than human brains, but we can leave that for a different discussion. Birds lack these folds entirely and until recently were not considered to have a cortex, the evolutionarily newest brain structure and a large part of why humans are so intelligent. 

People who study avian brains argue that the avian pallium actually functions a lot more like the mammalian neocortex than many in my field would like to admit. The bird pallium occupies the same proportion of the telencephalon (in mammalian development, this is what eventually becomes the cortex) and interacts with lower-order brain structures to guide complex behaviors such as singing the same way that a mammalian brain does. Here is a review on the topic if you're interested in learning more: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2507884/

I will leave you with another clip of Alex and a picture of my family's African Grey, Ruby.

Not impressive you say? If only you knew how high off the ground the toliet was. Several Ruby lengths at least.