The first steps toward discovery are asking the right questions. PhD candidate Leanna Matthews of Syracuse University in New York has embarked on a research project involving the hearing abilities in harbor seals.
Matthews is studying how female harbor seals respond to recorded vocalizations of male harbor seals while in estrus, a time when females are receptive to breeding. The recorded vocalizations are of male harbor seals varying in age.
Unlike the boisterous barking of sea lions that most people recognize, harbor seals are much more subdued, vocalizing only with the occasional low grumble or growl.
Humans still know very little about how marine mammals communicate. While the basics are understood, the depth and meaning of their communication remains a great mystery. Also unknown is the how human-made sounds may affect their behavior.
Matthews hopes that her research may help scientists better understand underwater noise created by humans and how it might affect wild harbor seal breeding behavior.
This research would not be successfully conducted in the field since the most accurate findings would come from limiting variables and collecting repeatable information. The first round of data collection took place at The Oregon Coast Aquarium with resident harbor seals Boots and Swap. Swap would be the first to participate.
Although a strange new box had been introduced to her pool earlier in the week, it was now playing recorded underwater sounds. Interestingly, Swap gave the box no attention. Then, the grumble of a recorded male harbor seal played through the ambient noise. Swap popped her head out of the water. Once she saw no other seals in her area, she dropped below the surface and swam immediately to the source of the sound; the box that hadn’t interested her until now.
Additionally, Boots, the second seal participant swam away from the sound of male vocalizations.
Initially unsure of what to expect, Matthews said, “No one has played back male vocalizations to captive female harbor seals. There is so much we don’t know about their biology and just having access to them gives me an opportunity to explore something biologists have pondered for a long time.”
Harbor seals are only in midst of estrus once per year. To solidify her findings, Matthews will return to the Oregon Coast Aquarium in summer 2016 to complete a second round of data collection. This second round of study will also include sounds created by human activity played through the box in an attempt to answer the second part of the initial question.
Studies conducted with the help of zoological animals such as this are a scientific gateway to obtain information impossible to collect from the wild. It is within these data that scientists and researchers are able to fully visualize what’s happening in places we can’t fully access or measure. In turn, this information could mean the difference between thriving populations and the threat of extinction for some animals.