Sabena Siddiqui is investigating the sounds humpback whales make when they are not singing, an aspect of their communication that is clearly important but little studied.
By Leah Sherwood.
Humpback whale songs have been famous since they were discovered by scientists in the 1970s. However, the whales’ non-song social vocalizations are a very under-studied area with few scientific researchers dedicated to it and only a handful of published scientific papers, few of which are focused on the humpback in Hawaiʻi.
Sabena Siddiqui, a graduate student at the University of Hawai‘i at Hilo, hopes to change that. She is researching the social sounds of Megaptera novaeangliae, known colloquially as the humpback whale.
“I study the non-song vocalizations—that is, all the sounds they are making when they are not singing,” says Siddiqui, who is doing her graduate work in the tropical conservation biology and environmental science program.
Siddiqui hails from Indianapolis, Indiana, and enrolled in the UH Hilo graduate program in 2015. She learned about the program after meeting Adam Pack, a professor and researcher at UH Hilo with joint appointments in psychology and biology whose research focuses on marine mammal behavioral ecology and cognition. Pack is a pioneer in the study of humpback whales in Hawaiʻi, and Siddiqui heard him speak during her internship at the National Oceanic and Atmospheric Administration (NOAA) in Woods Hole, MA, where she studied the bioacoustics of cetaceans.
After hearing Pack’s lecture, Siddiqui introduced herself and learned of the UH Hilo graduate program. She applied and was able to secure funding to attend UH Hilo through the National Science Foundation (NSF) Centers for Research Excellence in Science and Technology (CREST). The CREST award is partially funded by the Listening Observatory for Hawaiian Ecosystems (LOHE) bioacoustics lab at UH Hilo founded by Pack along with colleagues Patrick Hart, professor of biology, and Donald Price, former UH Hilo biologist.
Whale song versus social sounds
Siddiqui’s research focuses on spectral analysis of the social sounds of the humpback whale population that breeds in Hawaiʻi.
“The song is sung by males and mostly on the breeding ground,” she explains. “It is an interesting contrast to social sounds because social sounds are not only heard on their breeding ground. Social sounds can be heard while they are migrating, feeding, or breeding, and can be produced by males, females and calves. [This] is a whole other aspect of their communication that is clearly important but we don’t know anything about it. We don’t know even basic things, like the structure of the sounds or if there is a catalog of sound types. That is what I am trying to discover.”
See video footage and listen to the social sounds of four adult humpback whales recorded by Prof. Pack in waters off Maui, Hawai‘i:
Humpback whales are a highly migratory species and travel to Hawaiʻi every winter for their breeding season. “Hawaiʻi is this critical breeding ground for the entire North Pacific population. It is a very special area with high significance for these animals,” Siddiqui says.
“They spend their summers feeding in Alaska and other areas of the Pacific and North Pacific,” she continues. “They come here to breed, calf, and give birth so they are not feeding at all, the whole migration and the whole way back. They give birth in nice shallow warm areas for their calves to gain some strength before they make the huge migration back.”
The whales are known to adjust their communication when confronted with alien noises that interfere with the marine soundscape. Anthropogenic ocean noise has been increasing steadily due to activities like sonar testing and vessel traffic from commercial and recreational use. Siddiqui says whales are affected by anthropogenic noise more and more. Studies show that noise can change their behavior—it can make them change how they produce sounds—some become quieter, some become louder trying to “yell” over the noise.
“We know for a fact that this is happening and it is becoming more of a hot topic,” she says.
Scientists are also worried that anthropogenic noise is “blinding” the whales. “Sound is how cetaceans see,” says Siddiqui. “It’s like the equivalent of us being under constant strobe lights and we cannot escape it.”
In addition to her graduate studies, for the past seven years Siddiqui has served as the student chair of the American Cetacean Society (ACS), the world’s oldest whale conservation organization. Her role is to be a mentor and guide to student leaders of other groups on campus.
This year, the ACS board members voted to send Siddiqui as their observer representative to the annual meeting of the International Whaling Commission (IWC), which is a global coalition of 89-member governments charged with whale conservation and the management of whaling. All members are signatories to the International Convention for the Regulation of Whaling, which is the legal framework that IWC established in 1946. The annual meeting was held in Brazil this year.
“I would like to thank the American Cetacean Society Board of Directors for entrusting me with this amazing opportunity to represent the organization and serve as eyes and ears on the ground here at the IWC,” writes Siddiqui in her detailed blog composed while at the meeting. “It is truly an honor to see the inner workings of such a fascinating and important international body. Thank you ACS for your longtime commitment to being present and engaged at the IWC, may we protect cetaceans for many more decades to come.”
At the IWC gathering, Siddiqui attended many working groups and strategy meetings with U.S. and international non-governmental organizations. She sat in on meetings among country delegates, members of the media, and other NGO representatives to learn more about the current issues in conservation, aboriginal subsistence whaling, and whale killing methods and welfare issues.
“While at the IWC, I learned that it is more than an international body that regulates the use of whale stocks,” she says. “It is a landscape overrun by competing and conflicting interests, many of which are not related to the whales. It is dominated by unhealed wounds from historical wars, imperialism, and politics. Unfortunately, the whales serve as leveraged pawns in the political arena.”
She adds, with the perspective of a scientist, “The value that whales have on this planet extends far beyond the role that humans envisioned for them in societies and cultures. They are integral components of the planet’s health and in turn, our survival.”
About being part of the international conference, she says, “I learned a lot, my brain is quite full, and I am very grateful for the experience.”
This post was updated on Oct. 6, 2018, to add the video, the image of the sound spectra, and more information about the CREST award.
About the author of this story: Leah Sherwood is a graduate student in the tropical conservation biology and environmental science program at UH Hilo. She currently serves as an intern in the Office of the Chancellor. She received her bachelor of science in biology and bachelor of arts in English from Boise State University.