When It Comes To Bird Brains, Size Doesn’t Matter

Apr 25, 2017

Bird brains are the size of a nut, or possibly even smaller in some cases. But a plethora of new research shows that despite their small brain size, birds are actually among the most intelligent members of the animal kingdom.

“The Genius of Birds” (Penguin Books/2016) profiles a range of winged-beasts who are expert problem solvers and mappers with their own social networks and cultural traditions. Host Frank Stasio talks with science writer Jennifer Ackerman about her new book. Ackerman speaks tonight at Quail Ridge Books in Raleigh at 7 p.m.

Interview Highlights

On why Jennifer Ackerman wrote this book
I have been a bird watcher since I was a child… I have always thought birds were resourceful, but it was in the last 10 years or so that the studies began to come out about Betty The New Caledonian Crow who could bend a wire into a hook to get a little bucket of food from the bottom of the tube. And there was Alex, who partnered with Harvard scientist Irene Pepperberg to really show that birds have intellectual abilities that rival primates. And I got so interested in this idea that there was a lot more going on in terms of the cognitive capacities of birds that I wanted to delve into it.

On the structure of bird brains
We did think that because bird brains were so small and primitive...That they were really capable of only the simplest mental processes. But two things...Many species, have brains that are surprisingly large for their body size. It’s called relative brain size, and it’s true for our species too. And when it comes to intelligence what really matters is the density of neurons...Corvids and parrots have probably twice as many neurons in their brains as primate brains of the same size. And about four times as many neurons as mammal brains of the same size...And another thing that really matters in intelligence is the connection between neurons. And in that way, bird brains resemble ours in many ways. They’re wired together in complex pathways just as our brains are.

On Louis Lefebvre, a Canadian ornithologist
He devised the first scale of intelligence for birds. It was based on the idea that innovative birds, birds that are smart, do unusual and complex things in the wild. And he poured through probably 75 years worth  of ornithological journals to find about 2,300 reports of these very unusual behaviors in birds. He organized them by bird family and then ranked them according to their capacity for this kind of innovative behavior...And what were the smartest birds at the top of the scale? No surprise. They were corvids, parrots, birds of prey, gulls and herons, and even some small birds like sparrows, tits, and finches.

On bird songs
Birds learn their songs the same way that we learn language. It’s called vocal learning. And it’s very rare in the animal world... It’s very important for birds to have tutors. And so the process of vocal learning...It’s about imitating, practicing, honing your skills, experimenting. Birds have a period in their youth where they do something very similar to human baby babble. It’s called “sub song.” They just sing notes in different random orders. So, over time they learn to really refine their song skills and learn the particular songs of their species.

On the New Caledonian Crow
New Caledonia is the home of what is arguably the smartest bird in the planet--The New Caledonian Crow. This bird is an expert problem solver. It's also renowned for its capacity to make and use its own tools, complex tools on par with primates like chimps and orangutans. It’s the only species other than humans to make hook tools, and they make them in the wild. These are sticks with a little hook on the end that they use to poke into holes to grab grubs. Grubs are a fabulous source of nutrition...These styles of toolmaking are passed down over generations. The faithful transmission of tool design, that’s a very good definition of culture.

On birds “mobbing” and how they learn about new enemies
John Marzloff at the University of Washington had his researches wear a caveman mask when they caught crows and banded them. And catching and banding a crow is a fairly traumatic experience for the crow. So what Marzloff discovered was that when he and his group returned to this area where they had banded the crows, wearing the mask, they were mobbed by not just the crows they had banded but their family members, their offspring. This happened year after year after year...Up to 9 years later they were mobbing this cave man mask.

On the empathic nature of ravens
Ravens are very social birds. They live in groups. And it’s not a peaceful, kind of harmonious existence. They have a lot of fights and altercations. Ravens that are a victim of a conflict of some kind will be consoled by their mate or their ally, and this usually involved some kind of preening or twining bills which is the, kind of, bird equivalent of kissing. 

On how climate change impacts birds
We are creating a world that is well-suited to the generalists among the bird populations. The birds that are adaptable to human environments. And, you know, the house sparrow is a good example. It has a genius for using man-made materials. They like to use old cigarette butts to line their nests, because the nicotine drives away parasites. Some songbirds are very adaptable. They will change their songs so that they are heard over traffic noises. So those birds are thriving, and they are speciating.The birds that are going to be suffering, I think, are the specialists. And they are birds that are adapted to a very unique niche or habitat.