Gary Player was notorious for doing the amazing, and sometimes “impossible”. Jealous contemporaries sometimes commented negatively, to which he famously said “the more I practice the luckier I get”.
I have a friend who is a very good golfer and tends to get “lucky” very often. Every time he chips in from off the green, he irritates his opponents by saying “even a blind squirrel finds an acorn from time to time”.
Can blind squirrels find acorns? I am more interested in our avian friends and ask – can a blind bird find a mealworm? The little nieces are very clear on this – “Yes uncle George, they SMELL them”.
We know that sight is the primary sense by which birds find their sustenance. Hearing plays a critical role too, from the traditional bush telegraph at your feeders to the incredible audio senses of our owls. But what of smell, and what of taste? Academic sources are ambiguous on this. For the record, we at Nature’s Heart are predisposed through our own observation to believe that smell is important – at least in some birds.
Recently a customer ordered our “Orange Nectar” sachets, and told me that her birds refuse to touch the “Strawberry Nectar”, but “go crazy” for the orange variant. She lives in a drier area of the country. Anecdotally, we have noticed that in drier areas, orange flavoured nectar is more popular, but in wetter areas, strawberry nectar becomes more successful. Whether this is a valid observation or not is not very clear.
My usual “go-to” reference is “Avian Medicine: Principles and Application”. Sadly, it is rather quiet on this subject. The one snippet is:
“Olfaction is difficult to assess, because birds have a poor sense of smell… Birds with (olfactory) disfunction may exhibit an altered appetite or feeding response”. (In laymans language, if the bird has a problem with its sense of smell, it may not eat properly).
There is only a little more on a birds ability to taste, and it appears that birds have both poor taste and smell senses (on a comparative basis), but that both senses are present. What is more interesting is that a birds diet can be affected by causing a “trained response” in caged birds – it is very unlikely that this could happen in the example used of Orange v Strawberry nectar. As an aside, it emphasises how important a balanced diet is for the “companion” caged birds.
A “light bulb” moment for me was when I learned that turkey vultures use smell to locate food! I have watched turkey vultures circling. My guess is that they operate at about 100m above the ground, and they can smell carrion from that distance. Their sense of smell is so good that oil pipeline companies inject a scent that mimics carrion odour into pipelines – the birds are then used to find pipeline cracks, because they settle at those points.
Sadly, the vulture example (and others that may be selectively found), prove only that certain species of birds have a great sense of smell. Most of those we are interested in as garden birders (passerine birds) have long been considered to have the worst sense of smell of the birds. However, the ecologist Larry Clark in a 1993 experiment showed that passerine birds have similar olfactory acuity to rats and rabbits. Increasingly, recent research work seems to be showing that the physiology has resulted in incorrect interpretation of the avian sense of smell. Olfactory bulb size – where passerine birds tend to have small bulbs – has always been considered by biologists to be the measure by which the animal sense of smell is to be evaluated. In many cases there is a clear correlation (the New Zealand kiwi being one). New research leads us to suspect that the relationship does not obviously exist for passerine birds.
The jury is still very much “out”. We tend to go with the “birds have well adapted senses of smell” argument.
In our company, it is indeed the basis of the provision of odour in our nectar offering. We believe it acts as an “attractor”. Evidence shows that the nectar feeding birds are best fed by a sugar water mixture of 1:5 or 1:6 (never stronger than 1:4, but may be weakened to 1:10). Additives and colourants are discouraged, so we have taken trouble to come to an aroma solution that is perfectly safe for birds, and we are convinced that the birds are indeed attracted to the really wonderful scent.
Since we work so much on anecdotal evidence, we would be very keen to hear from the users of our product as to your experiences. Your typical geography and vegetation will also be of interest. Please email us on george@naturesheart.co.za – we would love to hear from you!
