At the end of 2008, the magazine Scientific American made a point of mentioning a discovery made by researchers at the ULg’s GIGA neurosciences unit, published in the journal Behavioural Brain Research. The Liège neuroscientists had just brought to light the involvement of certain olfactory stimuli in the reproductive behaviour of the Japanese quail. Confirmation that these birds were able to perceive smells despite having a poorly developed olfactory bulb.

That vultures more often locate their prey thanks to a highly developed olfactory sense has never been contested. Different experiments have moreover shown that such was the case that visual clues don’t play a predominant role in guiding them to decomposing animal carcasses. Around forty years ago, Bernice Wenzel, of the University of California at Los Angeles, became interested in other birds in a similar framework. She highlighted the fact that it was also through a sense of smell that the kiwi, the flightless New Zealand bird equipped with rudimentary wings, detects its food, buried in the sand. In the same way she also demonstrated that various sea birds, such as petrels, go on smells given off by dead fish to fly back against the wind to the shoals from which they draw their food. A simple but instructive experiment consisted of placing a sponge soaked in cod liver oil on an offshore raft. The sea birds flocked towards her, against the wind (figure below).

Up until around the beginning of the 1970s, scientific studies in their entirety considered that all land birds, beyond vultures and kiwis, lacked a sense of smell. Operant conditioning techniques were thus used by certain laboratories to revisit the question. From this work it emerged for example that, contrary to common opinion, pigeons perfectly discriminate smells, at least certain amongst them, but we still don’t know to what exact ends they use this faculty.

However the work by Floriano Papi and his colleagues at the University of Pisa provided a cluster of convincing clues according to which carrier pigeons draw up an ‘olfactory map’ of the region in which they live and could make use of it to get their bearings. As is underlined by professor Jacques Balthazart, of the GIGA Neurosciences (formerly the University of Liège’s Centre of Cellular and Molecular Neurobiology) the birds obviously do not smell their pigeon loft from a long distance but, according to the hypothesis, could connect the smell of the sea or the smell of a forest to wind direction: ‘Whilst it is contested by certain people, this theory has been confirmed in independent ways by many laboratories,’ he adds.