A survey in 2016 conducted by GQ magazine showed that most women prefer men with ‘dadbods,’ tall height, and most of all, squishy bums. In another study published in Plos One, researchers found that men and women both prefer male and female leaders with low-pitched voices as partners. Science observes that a preference for specific male qualities for mates is not only evident in humans, but also in animals.
Masculinity Preferences of Female Animals
It is common in nature for female animals to choose mates with certain male qualities. For instance, a study published in Animal Behaviour in 2008 reported that male Indian peafowl capture the interest of the females through their vocalizations. For male peacocks, mating calls, which is composed of several notes and sounds, are more important for their mating success than the birds’ colourful trains. In another paper published in Animal Behaviour in 1998, domestic chickens were found to select males with higher wingflapping rate. In the case of jumping spiders, a population of females showed bias for males that could produce complex seismic signals as reported in Behavioral Ecology in 2006. The concept of choosing a mate based on specific characteristics also holds true for the bush cricket.
Leadership Calls in Bush Crickets
Scientists Megan Murphy (now with Salisbury University) and Johannes Schul (with the University of Missouri) conducted a study to investigate whether the leadership calls of male Neoconocephalus katydids, or bush crickets, increase a female’s perception of the male’s quality as a mate. Their findings are published in Behavioral Ecology and Sociobiology.
Male bush crickets produce leadership calls by chirping signals, each competing to chirp first, leading the series of chirps. Interacting males compete to make these leading signals, with the winner having a large fitness advantage over the others even if there are no natural costs to producing the attractive signal. Murphy and Schul tested three species of bush crickets, one with leader preference (Neoconocephalus ensiger) and two without (Neoconocephalus nebrascensis and Neoconocephalus exiliscanorus), to determine whether there are links between leadership signal and male quality.
The leadership ability of N. ensiger was measured using the proportion of chirps that each male led during exposure with other males. On the other hand, N. nebrascensis and N. exiliscanorus do not exhibit competition over the leadership role but synchronize their calls together. Thus, the researchers used chirp periods during solo calling as measurement for leadership ability of these two species.
Leadership Does Not Indicate Male Quality
Results showed that there were no correlation between leadership and male quality in any of the three species used in the study. This result may imply that the leadership calls does not function as an indicator of masculinity or male quality.
This means that for N. ensiger, which exhibits leader preference, the leading call was not linked to costly call characteristics. The researchers reported that the leaders tend to have longer and slower calls compared to the followers. The degree of overlap between the two types of male calls would increase the length of the collective calls, which may catch the attention of female bush crickets.
It was observed that the leading calls were extremely repeatable especially during night time. This observation may indicate that the calls are used to convey a specific message about the male bush crickets. The variations in leading calls may be attributed to both genetic and environmental origins. Environmental factors such as conditions during their younger stages could have a permanent impact on leadership calls. Other environmental conditions like availability of food could also have a temporary effect on the males’ calls.
Furthermore, leadership ability was not linked to body size, condition, or fluctuating asymmetry of the three male species studied. This is consistent with the idea that there are no significant energetic costs in producing leadership chirps. However, the researchers perceive that the differences in producing leading calls may be linked to some male qualities.
No Fitness Benefit for Females
Though the study concluded that the females do not get fitness benefit by mating with males who make the leadership calls, additional research on female bush crickets might be necessary to prove this.