This olfactory abilities can be quite complex in some organism, like for example, the fathead minnows, Pimephales promelas, that can detect the number, size proximity of their predator by chemical cues alone. Others can use olfaction to assess their predators diet, thereby determining the threat posed by a given predator.
There is a certain common assumption that birds have a very weak scent of smell. There are a few exceptions. Tubesnoses may use their smell to detect decaying fish and plankton from kilometers away and Kiwis use it to locate their food on soil and mud.
Along evolution bird retain the anatomical and neurological structures for detecting olfactory cues and so use olfaction in some extent. Size and complexity of the olfactory bulb varies across taxa, and this variation is likely to be adaptive.
Passerines are those that are considered to have the smallest olfactive bulb. In a way to demystify this, some scientists investigated the ability of a bird to scent a predator.
They used houses finches and exposed them to a feeder/scent delivery mechanism. During the feeding time, birds were exposed to 3 different smells: cat fecal cues, rabbit fecal cues and water. The birds were unable to see the content of the stimulus cups.
After watching the records, they noted that house finches delayed the feeding time, spend less time on the feeding platform and reduced their vigilance on the different stimuli. Birds strongly responded to cat faeces. Scientist noted that the behavior of the bird was different on the presence of the mammal cues, and a normal behavior was kept when water was the cue.This simple experience is an evidence that birds can detect mammals cue while foraging. This type of studies, on animal behavior, became important to understand certain ecological mechanisms. Understanding the nature is also taking part of their conservation.
Author: Sónia Manso
