ASU News

First evidence of paternal voice recognition in solitary foraging species found

November 30, 2012

Think of the last time you screamed. Chances are you attracted someone’s attention. What about the last time someone flirted with you? You were likely more selective in your response.

New research findings from Arizona State University and the University of Veterinary Medicine Hannover in Germany demonstrate that a less social species – the grey-mouse lemur – pays attention to alarm calls regardless of whom they emanate from, but they are selective when it comes to mating calls from their fathers, paying more attention to calls from unrelated males.  Grey-mouse lemur Download Full Image

Findings from the study that analyzed grey-mouse lemur calls provide the first evidence of paternal kin recognition through vocalizations in a small-brained, solitary foraging mammal, said Sharon Kessler, the principal investigator for the study and ASU School of Human Evolution and Social Change graduate student.

Grey-mouse lemurs serve as a model for the early primates from which humans evolved, she added. Early primates likely shared traits with the lemurs such as foraging in dense forests and hunting for food at night in solitude, but also engaging with each other in social groups.

“Species with less complex social systems can be models for early primates, so we can learn about our own evolution," Kessler says. "We think that the earliest primates were very much like mouse lemurs.

“The study allowed us to go back further in time and to take a deeper approach into time. It suggests that kin recognition through vocalizations was important for primate evolution.”

The research indicates that sounds made by animals have been a vital tool to recognize kin since before complex social systems evolved in primates, “basically since the origins of primates,” Kessler said.

Studying an animal that forages in solitude, and not in groups as do monkeys and apes, allowed researchers to model how important kin recognition through voice would have been in a similar species from 55 to 90 million years ago.  Findings were published online Nov. 30 in BMC Ecology.

“It suggests that the paternal kin recognition can evolve without having a complex social system,” Kessler said.

The research team’s work began in 2008 to examine whether or not animals with smaller brains relative to body size could recognize kin through vocalizations as they forage by themselves at night. Calls were measured through frequency (how high or low the voice is) at various time points in the call, duration and intersyllable interval (how rapidly the call is repeated).

“Vocalizations are particularly important because you can communicate over a distance,” Kessler said. But danger sometimes lurks in the form of predators that may hear the calls. Mouse lemurs can communicate in the high frequency and ultrasonic ranges that are too high for humans to hear. This is also too high for predators like owls to hear, meaning that that mouse lemurs can communicate without being eavesdropped by predators. 

Findings of the study showed that females distinguished their fathers from unrelated males using mating calls. One explanation for being able to recognize paternal kin may be that females can use the calls to avoid mating with relatives, Kessler said.

It’s compelling to consider how mouse lemurs distinguish the calls since the species is raised only by mothers, aunts and grandmothers, she added. Fathers don’t help with infant care and don’t share the nest with the mother and babies, so learning a father’s voice while growing up doesn’t seem possible.

One possibility is phenotype matching. If family members sound similar, females may compare calls of potential mates to their own calls and to the calls of their brothers (littermates) in the nest. Then if they choose mates that sound different from themselves and their brothers, they would be choosing unrelated males.

Authors of the article "Paternal Kin Recognition in the High Frequency / Ultrasonic Range in a Solitary Foraging Mammal," are: Kessler, ASU School of Human Evolution and Social Change and Institute of Zoology, University of Veterinary Medicine Hannover, Germany; Leanne T. Nash, ASU School of Human Evolution and Social Change in ASU's College of Liberal Arts and Sciences; and Marina Scheumann and Elke Zimmermann, Institute of Zoology, University of Veterinary Medicine Hannover, Germany.

This research was funded by the German Research Foundation, Sigma Xi, the Arizona State University School of Human Evolution and Social Change and the ASU Graduate and Professional Student Association.

ASU News

Article spotlights shortage of males in nursing

November 30, 2012

It was men who attended the world’s first nursing school in India in 250 B.C., yet today, the percentage of practicing male nurses in the United States hovers at a mere six to seven percent. How can that be?

“Men in Nursing” is the featured article in the Fall issue of Innovations in Nursing & Health magazine, published by ASU’s College of Nursing and Health Innovation. The article discusses the gender disparity in the nursing field, why stereotypes endure and what can be done to encourage more men to join the profession to correct the imbalance. "Men in Nursing" is the featured article in the December issue of "Innovations in Nursing & Health" magazine, published by ASU's College of Nursing and Health Innovation. Photo by: ASU College of Nursing and Health Innovation Download Full Image

The reasons for the imbalance stems from the simple fact that nursing is traditionally perceived as a “woman’s job.” The nursing profession needs to place greater emphasis on recruiting men for a variety of reasons, particularly the projected shortage of 260,000 nurses in the United States by 2025.

Teri Pipe, dean of the College of Nursing and Health Innovation says, “At ASU we are always looking for more ways to provide an inclusive learning environment. We look for ways to provide positive role models. We need to do a better job of getting the word out about all of the roles in nursing, the variety of things people can do and the flexibility that comes with a nursing degree.”

Pipe said opportunities abound in everything from informatics to working in communities critical-care units and emergency departments, and performing research, as well as administrative roles.

For Joshua Stark, 27, who is in his final year at ASU’s College of Nursing and Health Innovation, it’s a way to connect with his fellow man. Stark recently completed an OB/GYN rotation and said the new dads were appreciative of having a male nurse on-hand during labor and delivery. “The dads loved having a male nurse because they weren’t the odd man out,” Stark said. “Nursing is a field for intelligent, passionate people who truly care about others. None of those qualities are specific to either gender.”

The article suggests that nursing’s academic leaders should partner with schools and community-based organizations to reach potential students, offering loans and grants that target students in accelerated-degree nursing programs where the students are more likely to be male. The American Assembly for Men in Nursing recently introduced the Future of Nursing Campaign for Action, pushing for an increase in the percentage of male nursing students from its current 12 percent to 20 percent by 2020.

To obtain a copy of the Fall issue of Innovations in Nursing and Health magazine, visit


Reporter , ASU Now