Let’s take time to examine what appears to be a mystery but is a reality. Birds are a special kind of creature and one of the most sensitive. They can recognize the taste of soil rich in worm just by pecking the ground with their beak a few times.
You may start to wonder what a bird is seeking to take out from the ground, but then you are taken aback when you see it pluck out its prey gloriously from the ground. In the aspect of taste, you won’t find robins to be responsive.
If you have seen robins tilt their head from side to side just before plunging their bill to the ground to pull out a worm and you wonder how sharp that sight is that it could pick precise movements of a worm, you will appreciate the good ability of a bird to sight preys from the soil.
In the mid-1960s, Dr. Frank Heppner carried out a test with a robin. He performed controlled experiments to figure out how possible it is for a robin to find its food. These experiments were conducted in stages to best test all five sense cues.
In the year 1965, Dr. Heppner realized that robins found it easier to make a good visual on worms, so he made a report on the outcome of his experiment, which could reference other experiments. At that time, they concluded that robins found worms for food, especially by their ability to see what other birds will pass by. Every bird you see, staring sternly at the ground, is likely to have found delicious earthworms.
After Dr. Heppner’s tests were used to know the sensory cues of robins and to determine which is dominantly used to locate earthworms, young biologists Dr. Robert and Dr. Patrick decided to share insight with already found knowledge on robins.
Further experiments were conducted by these biologists to investigate the thesis of Dr. Heppner. They found out that robins use a combination of sensory cues in finding worms, which means that while the robins have a good look at the worms on the ground, they are also making use of the hearing cue to search for worms hiding underneath the soil.
Even if it is easy to hear and search for worms, robins still need to complement this with a visual aid to know the worms’ actual position. You can imagine trying to kill a mosquito because you hear it fly just past your shoulder. Oh yes, you still need to turn on the light to kill the annoying insect.
The sense of smell is not common with the robin and other birds in helping them search for worms, probably because it is meant for animals of higher class. For instance, the hammerhead shark would pick up the smell of blood in the water from a far distance. This shows how important smell is to birds as much as hearing is.
Vibration is another cue that is not much of an exclusive ability for a bird to find worms because it is believed that even a robin should be able to pick up worm vibrations from the ground.