How Can Mammals Learn New Vocalizations and Can Humans Learn How to Reduce Environmental Stressors to Maintain Critical Ecosystem Functions?
The Detlev W. Bronk Alumni Lecture
- Friday Lecture Series
Peter Tyack, Ph.D., professor of marine mammal biology, school of biology, Scottish Oceans Institute, University of St. Andrews
Dolphins, seals and whales join elephants as the only mammals other than humans shown to produce novel vocalizations by matching sounds that they hear. This ability of vocal learning is critical for human language and songs of many birds but is rare among terrestrial mammals. Dr. Tyack will discuss evidence for complex vocal learning in marine mammals, including imitation of speech in seals, of synthetic and natural sounds in dolphins and changes in the songs of whales that must be learned. Preliminary evidence on the neural basis and evolution of these skills suggests that a broader comparative approach to vocal learning among mammals will help us to understand the evolutionary origins of human vocal learning. As top predators that feed as deep as 2000m, marine mammals are also good indicators of ocean health. Efforts to protect these animals used to focus on limiting hunting to sustainable levels, but human activities now stress marine life in complex ways. Our understanding of how the cumulative effects of multiple stressors interact is insufficient to allow us to identify when cumulative effects risk transitioning a population or ecosystem to an adverse state nor to identify practical reductions in stressors to reduce these risks. As human stressors increasingly threaten ecosystems on which we depend, our institutions must dramatically increase research that can help us manage these threats.
Peter Tyack’s interest in marine mammals was stimulated by their remarkable abilities to produce novel sounds by matching sounds that they hear. His Ph.D. thesis research at Rockefeller demonstrated that the songs of humpback whales change over time in a way that must be learned. Working with engineers at the Woods Hole Oceanographic Institution, he then developed electronic tags that could record sound and movement behavior continuously on marine mammals, an important new method for animals that are frequently out of sight and impossible to observe. Tagging allowed him to demonstrate that dolphins copy the individually distinctive signature whistles of partners; dolphins can use these copies as learned vocal labels to address one another. Working at sea, Tyack observed that anthropogenic sound often interfered with marine mammals’ use of sound, raising concerns about noise pollution. Tags that record dosage of sound along with behavioral responses have enabled dose-response studies on effects of noise that have guided national and international regulations. This discovery of unexpected harm from a new stressor led Tyack to focus on cumulative effects of multiple stressors on wildlife and ecosystems. Tyack chaired a National Academies panel on this topic, whose report emphasized the weak state of scientific knowledge to address this problem. As human stressors increasingly threaten ecosystems on which we depend, our institutions must dramatically increase research that can help us manage these threats.
- Open to
- Sidney Strickland
- Refreshments, 3:15 p.m. - 3:45 p.m., Abby Lounge
- Justin Sloboda
- (212) 327-7785