Evolution News reports on a new study about my favorite creatures of all: birds!
Next time someone calls you a birdbrain, smile and say “thank you.” Our feathered friends come well equipped with hardware and software for complex behaviors. A new study published in the Proceedings of the National Academy of Sciences puts birds on par with macaques and other mammals, and even suggests they can think.
Here’s what the news from Vanderbilt University says about the results of a detailed study by researchers primarily from the University of Prague, with additional team members from Austria, Brazil, and the United States:
The macaw has a brain the size of an unshelled walnut, while the macaque monkey has a brain about the size of a lemon. Nevertheless, the macaw has more neurons in its forebrain — the portion of the brain associated with intelligent behavior — than the macaque.
That is one of the surprising results of the first study to systematically measure the number of neurons in the brains of more than two dozen species of birds ranging in size from the tiny zebra finch to the six-foot-tall emu, which found that theyconsistently have more neurons packed into their small brainsthan are stuffed into mammalian or even primate brains of the same mass. [Emphasis added.]
How is this possible? The answer includes miniaturization and efficient packaging:
That is possible because the neurons in avian brains are much smaller and more densely packed than those in mammalian brains, the study found. Parrot and songbird brains, for example, contain about twice as many neurons as primate brains of the same mass and two to four times as many neurons as equivalent rodent brains.
Not only are neurons packed into the brains of parrots and crows at a much higher density than in primate brains, but the proportion of neurons in the forebrain is also significantly higher, the study found.
The scientists note that even despised birds like pigeons show much the same brain power. Powered flight, obviously, takes a lot of hardware and software to operate in any bird; how much so in the supreme flyers Illustra Media showed in Flight: The Genius of Birds: starlings, Arctic terns, and especially the tiny hummingbirds? […]The small heads of birds belie the observations of complex behaviors they perform.
But it’s not just routine tasks the brains must perform. Some birds can remember where they stored hundreds of seeds. Birds have been observed to hide a seed while another bird is watching, then move it when the neighbor is gone — indicative of a possible ‘theory of mind’ that shows planning and recognizing what the other bird is thinking.
The study provides a straightforward answer to a puzzle that comparative neuroanatomists have been wrestling with for more than a decade: how can birds with their small brains perform complicated cognitive behaviors?
The conundrum was created by a series of studies beginning in the previous decade that directly compared the cognitive abilities of parrots and crows with those of primates. The studies found that the birds could manufacture and use tools, use insight to solve problems, make inferences about cause-effect relationships,recognize themselves in a mirror and plan for future needs, among other cognitive skills previously considered the exclusive domain of primates.
Indeed, crows have shown the ability to solve a puzzle made famous in an Aesop’s fable (Reuters): dropping stones in a pitcher to raise the water level in order to get a drink. New Caledonian crows have shown the ability to use three tools in succession to reach a food source (BBC News). Owners of parrots know the cleverness of their pets; their ability to mimic human speech and singing is astonishing. Some cockatiels can even do the Riverdance.
I love cockatiels and green cheek conures, they are my absolute favorite birds. Absolutely adorable creatures!
Anyway, the rest of the Evolution News post notes that this intelligence is a problem for naturalistic evolution. Specifically, it’s a convergence problem – the same capabilities being evolved independently, without recent shared common ancestry. How can birds and mammals, who don’t share recent common ancestors, have evolved the same capabilities, e.g. – vocal learning pathways, by chance? There is an explanation that does explain the observations, however – common designs made by a single designer.
- New study: tiny songbirds fly over the Atlantic ocean and back each year
- New study: bird origins poses a convergence challenge to common ancestry
- New study: another biological Big Bang, this time for bird development
- New study: how the hummingbird performs stunning feats of aerobatics
- Shorebird’s beak inspires researchers to design new water collection strategy
- The best explanation for the design of bird wings is intelligent design
- Scientists trying to mimic the design of hummingbirds with nanorobots
- New peer-reviewed article argues for irreducible complexity in birds