From the eerie croak of a tropical frog to the haunting call of the howler monkey, the animal kingdom is filled with wild and wacky mating calls. But which do humans find most appealing? Scientists have developed an innovative online quiz that asks participants to listen to two calls from males of the same species and select the one they deem most attractive or interesting.
Shared Tastes Between Humans and Animals
While it might sound like a bizarre question, researchers from the Smithsonian Tropical Research Institute have discovered that humans and animals share remarkably similar tastes. The team aimed to determine whether the features that make certain animal calls irresistible to females of the species would also resonate with human ears. Each question in the quiz compares two calls from species where scientists have identified a strong preference for a specific type of song.
The 'Calls of the Wild' Quiz Findings
Dr. Logan James and his co-authors created the 'Calls of the Wild' online quiz to test if human acoustic preferences align with those of animals. Over 4,000 participants from around the world assessed 16 pairs of calls from different species, voting for which they believed sounded better. Surprisingly, the results revealed that people frequently agreed with animals. Humans appear to pick up on and enjoy the same features of mating calls as a wide range of animals, including birds, amphibians, primates, and even insects.
The researchers found that the stronger a species' preference for a certain type of call, the more likely humans were to select that call as their favourite. Additionally, humans were faster to choose a sound as their favourite when the species exhibited a stronger preference for one call over another. This overlap in subjective preferences suggests that the features animals consider 'beautiful' often parallel human preferences, possibly due to similar sensory systems or universally appealing acoustic qualities.
Acoustic Adornments and Frog Calls
Dr. James explained to the Daily Mail: "We found strong preferences in both animals and humans for acoustic 'adornments'. These are extra sounds that can be added on, such as clicks, chucks, and trills, which everyone seems to like." By choosing which call is better, participants can discover which animal they share the most musical sensibilities with. For instance, scientists found that humans agree with animals like the túngara frogs, as both prefer mating calls with greater complexity.
Inspiration from Frog Research
The researchers drew inspiration from scientists Stanley Rand and Michael J. Ryan, who in the early 1980s pinpointed the exact feature of a frog's call that made it attractive. They discovered that female túngara frogs, small pond-dwelling amphibians found in Mexico and northern South America, choose mates based on call complexity. Male frogs produce a long whine followed by a series of short 'chucks', and the more chucks they produce, the more interested females become.
However, female túngara frogs are not the only ones listening to these calls. Predators like the frog-eating fringe-lipped bat eavesdrop on these courting rituals and, similar to females, tend to target males with more complex chucks. Mr. Ryan noted: "Darwin observed that animals seem to have a 'taste for the beautiful' that sometimes parallels our own preferences. We show that Darwin's observation appears true in a general sense, likely due to the many sensory system properties we share with other animals."
Why Depth Matters in Mating Calls
The deep bass tones of singer Barry White have become synonymous with seduction among humans, but it appears horses also find deep voices attractive. Studies indicate that female horses are more drawn to stallions with deeper, lower-pitched whinnies. Lower frequency 'voices' in stallions are often associated with larger males, calmer temperaments, and offspring with higher survival rates.
Researchers suggest that mares make choices about unfamiliar males during first meetings based on voice depth. Similar to humans playing an album featuring Barry White's bass-baritone voice, deeper whinnies from male horses seem to enhance the mares' mood. These findings could potentially assist horse breeders in selecting the best stallions for mating in the future, highlighting the practical applications of understanding acoustic preferences across species.
