Being bird brained .... is it that bad?

This was originally posted at www.ecolgoyweb.net on Sat/Oct/2005 14:37

By David Nowell
FAO Casa Gazette, October 2005

Frequently the term “bird brained” is used to refer to fellow individuals (humans) who are perceived to have reduced intelligence or intellect, or individuals being small minded or having done something less than intelligent. However, some people have recently been astounded to find that a number of the intelligence characteristics (such as language, tool use, awareness of self ad others, and deception) originally though to be entirely human are not only found in some mammals, but also in birds. Perhaps those that are most astounded were being “bird brained”.

Bad jokes aside, there is mounting evidence that birds develop skills that were previously thought impossible, and these skills are associated with brain functions normally only associated with intelligent species. Sometimes these skills are developed at short notice.

Vocalization
Some species of birds show definite learning skill; they sing a song that is a bit of mess at the beginning of their first season, but after a couple of weeks of practice become much better at singing the species' “ anthem”. In the wild though these birds learn from their own species.

Some birds learn, even in the wild, from other species and the ability for birds to mimic other bird calls suggests a significant degree of memory and logic at times. Not only can they mimic similar bird calls/songs, but those calls belonging to a wide range of bird species and vocalization activities e.g. red-capped robin-chat or Natal robin (Cossaypha natalensis) or Australian magpie (Gymnorhina tibicen). Starlings (Sturnus vulgaris) for instance will copy the whistles of various shore birds as well as the sound of other songbirds, even mechanical sounds, and incorporate them into their song. One of the greatest song mimics though are the Marsh Warblers. Scientists have recorded and distinguished the calls of over 200 other bird species being used by Marsh Warblers, though not all by the same bird.

It is well known that a variety of birds can be trained to “talk”, or at least repeat words or simple sentences e.g. parrots or the common mynah (Acridotheres tristis). A quite startling recent fact is that an African grey parrot (Psittacus erithacus) has been shown to have a vocabulary of over 900 words and can construct simple sentences in response to changes in the environment or the situation i.e. it creates simple sentences and may we even dare say “hold a rudimentary conversation”. The vocal / speech ability of this parrot has been substantiated by a number of well known anthropologists, including Jane Goodall of primate research fame. A simple vocal exchange / conversation with the parrot could certainly beat talking to oneself, or a partner who practices selective hearing or does not respond.

Use of Tools
There were very few examples, outside the human species, of clear planning of original solutions to new problems by individuals. However, on closer examination in recent years some bird species show this characteristic very clearly. A whole variety of birds are able to utilize tools, construct simple tools, and even construct tools from materials they have never encountered before. Birds ability to use tool goes as far back as the late 1940s when the Galapagos Islands Woodpecker Finch (Geospiza pallida) were found to routine spear or pry out grubs from under bark with twigs. The recent classic example is the New Caledonian crow (Corvus moneduloides) called Betty. Although the phenomenon of New Caledonian crows developing tools in the wild (such as developing wire or wooden hooks to remove insects from wood) has been carefully documented by some, Betty has been carefully studied in a “laboratory” and there is no doubt that she not only has the ability to solve problems, but to develop specific tools for a given occasion. In the wild, these birds are known to store their tools after use so they are available for repeated use.

Tool usage has also been found to occur in Varied Sitellas (Daphoenositta chrysotera), crested shrike-tit (Falcunuus frontatus), grey shrike-thrush (Colluricincla harmonica) and white-winged chough (Corcorax melanorhamphos) in Australia. Many other tool using species from around the world have been documented in more recent years.

But what else can they do?

Fire and fishing: Black kites (Milvus migrans) have been known to pick up smouldering sticks from areas recently burnt by a bush fire and drop them into unburnt areas so that they can feast on the small mammals that flee from the resulting fire. They have also been observed dropping “bait” into a lake to bring fish to the surface so are easier to catch.

Deception: white-winged chough (Corcorax melanorhamphos) in Australia are known to be very cunning. Young birds often pretend to help feed the chicks (they are often too hungry themselves to help properly) at another bird nest, or only assist with a task such as preening when other birds are within sight, in order to convince onlookers they are valued members of the group. This probably has to do with social acceptance and status.

Anting: Perhaps some of the strangest behaviour indulged in by birds is anting. Anting occurs either as active anting, in which the bird picks an ant up and applies it to its plumage, or passive anting. Normally, the ant during active anting will be stroked along the feathers, usually the flight feathers. Over 250 different species of birds have been recorded displaying this behaviour at one time or another. Starlings (Sternus vulgaris) actively seek out formic acid producing ants which suggests that the ants' ability to spray formic acid is an important consideration. It has been observed by many people that during anting the birds appear to get exceedingly excited. After the ant has been applied to the feathers it is either discarded or eaten. Other active anting birds are Babblers, Tanagers and Weavers.

Passive anting involves the bird finding an ants' nest and lying down among the ants. This process often likened to bathing in ants is not as well studied as active anting. Birds which are passive anters include the European Jay (&hellip, Crows and Waxbills. The Blackbird (Turdus ….), Redwings and other thrushes exercise a flexible strategy, being either passive or active anters as the occasion or some unknown need takes them.

What actually happens during anting is easy to observe and record, especially as many birds will display anting activity in captivity if offered ants. A more difficult question to answer is why. In truth nobody seems really sure what birds get out of anting. People have theorised that the ants help rid the birds of pests like feather mites and louse flies, other theories suggest that the anting is just a way of getting the ant to discharge its store of formic acid before eating it. The trouble with this idea is that it doesn't explain passive anting. Scientific evidence supporting the pest control theory is hard to find. However, it is known that ants are only eaten after they have discharged all of their acid. It is not unreasonable to assume that active anting as we see it today evolved from a detoxifying action to make ants edible but gave the added benefit of pest control to some extent. Nature often likes to perform several roles with one action and though scientists like to understand the order of importance and/or the order of origination of an action this is not always easy to achieve.

Memory: Some people claimed that animal with the best memory on earth is the bird! AN example of extraordinary memory is shown by Clark’s nutcracker (Nucifraga columbiana). This North American bird collects up to 33,000 seeds in November each year which it buries in over 2,500 food cache sites over an area that may measure 300 km2. Over the next 12 months it retrieves over 90% of these sees and some may be buried by more than a metre of snow!! ........ migration, storage of food.

Innovation: The Japanese crow (Corvus corone) were found to crack walnuts by placing in them in the path of traffic. When the lights changed to red they hopped down to the road and placed nuts in front of waiting cars. When the lights turned green, the birds flew to safety while the motorists drove over the nuts and cracked them open. Again when the lights turned red, they jumped onto the road and ate the freshly cracked nuts. Image if our brain could do that, particularly in response to exams!

The black-breasted buzzard (Hamirostra melanosternon) are known to drop stones onto the nest eggs of Emu (….), bustards and Brolga (…..) in order to break open the eggs so they can eat the content. As are Egyptian vultures (…&hellip known to use stones to break ostrich (Struthos ….. ) eggs.

Faeces: burrowing owl (Athene cunicularia) are widely known to collect mammalian dung and place it around their burrow / nest. This has now been shown to act as bait for their primary food – dung beetles. They are known to stand motionless outside their burrows and then pounce on any unsuspecting dung beetle that may wonder near the burrow. The use of dung as a tool significantly increases the both the number of species and beetles it catches each day.

The bird brain

Recent studies have shown there is a strong direct relationship between increase size of a bird’s forebrain and the frequency of feeding innovation. Bird’s forebrain is usually about 5 times the size of the hindbrain. However, 2 groups with prominent forebrains are “corvids” (crows, magpie etc) and parrots which have increased ability to solve challenges, reasoning and language.

Studies also suggest that the bird brain is far more malleable than that of the human. The formation of spatial memories (such a relocating stored food) triggers massive increases in the number of nerve cells that migrate to the hippocampus (which is known as the area for spatial memory). As a result a bird’s hippocarpus may swell over 30% in only a few weeks. As maintaining this brain matter is expensive in terms of energy, it shrinks again when this memory demand has passed.

Investigation of songbird brains show that discrete brain structures are required by songbirds and such studies are giving us insight into basic issues of neuroscience that are applicable to other species.

Where does that leave us?
Clearly we are not the only animals on earth with intelligence and the ability to reason and solve challenges. Perhaps man is more impressive than any other animal in this regard, but we are less unique than we thought a few years ago. I suspect many of the current concepts and theories relating to bird behaviour will have to radically change. Over the next decade or so, we will learn an increasing amount about birds and their ability to think and/or reason, their memory, and behaviour. Complex social ornithological behaviour that we currently do not understand (or perhaps even some of those we think we understand) may become more understandable, provided we studied it more carefully and did not restrict ourselves to looking for the answers within normal “expected” bird behaviour from a current human knowledge perspective.

And now, what do we do with the usually standard sayings such as “being bird brained” or “learning like a parrot”? Perhaps we could still use these expressions, but we will now have to use them more carefully in a variety of very different or new contexts. Given the way my memory normally behaves, I could probably only benefit from having a bird brain – a “ food storage” bird brain that is.

Additional reading
Boland, C. 2003. Bird brains. Nature Australia 2003-2004. pgs 47-53.
Hunt, G.R and Gray, R.D. 2003. Diversification and cumulative evolution in New Caledonian crow tool manufacture. Proc. R. Soc. Lond. 270: 867-874.
Levy, J.L., Duncan, R.S. and Levins, C.F. 1004. This bird distributes animal dung in and around its brrow to provide bait for its prey. Nature 431:39.