Scientists are tracking humpback whales by listening in on the songs they sing as they migrate past NZ each year on
their way to breeding grounds nearer the tropics.
Each winter, humpback whales migrate north from Antarctica feeding grounds to breeding grounds, passing New Zealand as
they go. Because humpbacks are ‘vocal learners’ who learn songs from each other, the patterns and similarity in their
song provides an auditory clue as to where they have been and where they might be headed.
A new acoustic study focusing on humpbacks aimed to find out which breeding ground they were headed to by comparing the
song patterns of individual whales. This study follows previous research
which found humpback whales on their annual migration south to feeding grounds in Antarctica gather at the Kermadec
Islands for a form of whale ‘karaoke’.
Associate Professor Rochelle Constantine and PhD student Victoria Warren from the University of Auckland’s Joint
Graduate School with NIWA, used recordings from acoustic loggers up to 60m below the surface in locations where
humpbacks are more likely to be seen passing by New Zealand including Cook Strait, the South Taranaki Bight, Wairarapa
Whale song was picked up by the recorders at these locations and then compared to songs recorded at two main breeding
grounds: East Australia (off the north eastern coast of Australia) and at New Caledonia. The recordings were made in
2015 and 2016 by scientists from the Institute of Research for Development, University of Queensland and University of
The acoustic tracking also provided new information on which route past New Zealand they were more likely to take.
The study found that song recorded at New Zealand locations was similar to that recorded at New Caledonia but less
similar to recordings made at East Australia, suggesting passing humpbacks have a stronger connection to the New
Caledonia breeding grounds.
That finding aligns with genetic sampling of humpback whales off the New Zealand coast.
It also highlights the different routes humpback whales take when they pass New Zealand on their southern or northern
migration. Northern migrating whales are more likely to pass through central New Zealand waters on the way to New
Caledonia but whales migrating south later in the year are further offshore and likely come from a wider variety of
“Tracking any migratory animal is a challenge simply because of the distances involved,” says Associate Professor
Rochelle Constantine from the University of Auckland. “This is particularly so when it comes to marine species, but
acoustic monitoring is proving to be a valuable and useful tool to help us better understand humpbacks in the western
South Pacific and how populations are recovering from whaling.”
Ms Warren says the study provides new insights into the connection between New Zealand humpback whales and their
“Song transmission between whales and the evidence it provides on how whales are connected to specific locations is a
really good non-invasive method to help us better understand where these whales go each year and how they get there.”