By Insight Post Uganda
A recent scientific study has unveiled a strange way Nile crocodiles exhibit a sensitive reaction to the cries of both infant chimpanzees and human babies.
Researchers from the University of Saint Etienne and the University of Lyon in France orchestrated an experiment that underscored the crocodiles’ heightened reactivity to escalating stress levels and cries, reflecting the vulnerability of their potential prey.
This study published in a respected scientific journal called Proceedings of the Royal Society B: Biological Sciences, aimed to understand how crocodiles react to the cries of babies. It was conducted in CrocoParc, located in Agadir, Morocco, which houses more than 325 Nile crocodiles.
The researchers creatively played distressing sounds, like the cries of young chimpanzees and the sad wails of human babies, using carefully positioned loudspeakers.
The Nile crocodile, scientifically known as Crocodylus niloticus, is deeply found in the sub-Saharan African landscapes. These creatures, whose prime habitat encompasses lakes, rivers, swamps, and marshes, have been known to thrive in the embrace of aquatic expanses.
While their capacity to tolerate saline surroundings is notable, their heartland remains firmly rooted in freshwater domains, occasionally venturing into brackish lakes and deltas. Long ago, their realm extended even to the Nile Delta.
Adult males, typically measuring 3.5 to 5 meters in length and weighing between 225 to 750 kilograms, exhibit astonishing variations in size, with some reaching an astonishing length of 6.1 meters and a weight surpassing 1,000 kilograms.
Previous studies have shown that when crocodiles hear signals of distress from animals they could potentially prey upon, they become extremely alert and are often prompted to move towards the source of the distress sounds.
Following the Moroccan experiment, a question emerged. Would crocodiles react in a similar way to distress sounds from primates, even though primates are not typically considered part of the crocs diet?
However, out of curiosity, the researchers gathered a set of audio recordings, each capturing the emotional cries of distress of regular chimpanzees, the fascinating Bonobo chimpanzees, and human babies. Each category of sounds gradually increased in intensity, creating a spectrum of distress calls.
The human cries that were recorded ranged from the cheerful babble of babies to the sobbing calls of toddlers, who were four years old and younger. These cries were heard in the comfort of their homes or even during less enjoyable but essential vaccination procedures.
The unfolding observations carried a certain style. Nile crocodiles, seemingly drawn by an irresistible force, exhibited a remarkable connection to the pained cries of severely distressed infants. As the cries grew louder, their reactions intensified, echoing the crucial junctures when their potential prey becomes most exposed.
Gender also played no role in this response, as both male and female crocodiles exhibited similar behavior. Some turned their heads or moved closer to the origin of the distress sounds. Driven by their primal instincts, a few even dared to snap at the enigmatic speakers themselves.
However, a subtle pattern emerged in their reactions, intricately tied to the intensity of the distress sounds. The crocodiles’ responses, resembling the rising and falling of a musical composition, exhibited a deliberate progression.
Around one-fifth of these top-tier predators displayed interest when exposed to the soft cries of mildly distressed human infants. In contrast, about one-third showcased an amplified reaction to the unrestrained, intense wails of infants experiencing more significant distress.
The researchers emphasize the significance of their discoveries with eloquent precision. While these experiments don’t provide a complete understanding of crocodile behavior, they do illuminate a dimension of their nature-opportunistic hunting combined with a keen awareness of distress signals in sound.
This scientific symphony unveils that these creatures, seemingly crafted from ancient legends, possess a connection to auditory cues that accentuate moments of distress.
In Uganda, Nile crocodiles are native species but unfortunately, there have been reported cases of Nile crocodile attacks on people, including children and infants, who were near or in water bodies where these crocodiles reside.
These attacks can occur when people are fishing, swimming, bathing, or carrying out other activities near the water. Nile crocodiles are known to be opportunistic predators and may view humans as potential prey, especially if they are near the water’s edge.
Authorities and local communities often take measures to raise awareness about the risks of crocodile encounters and implement safety measures to reduce the likelihood of such attacks.