It’s possible that recent observations indicate that Humpback Whales are now calving considerably farther south than previously believed. This remarkable find raises many questions and opens exciting new doors about the migration patterns of these majestic creatures. Up until this study, researchers thought that Humpback Whale calves were born exclusively north of 28 degrees latitude along Australia’s eastern coast. They had assumed an absence of births south of 23 degrees latitude on the western margin. Recent sightings have shown more than 200 newborn calves taking to the waters. These calves range as far south as 43 degrees S, particularly around Tasmania and New Zealand…from North American continent!
By the middle of the 20th century, we almost wiped Humpback Whales out completely. Conservation efforts, including site protection and captive breeding programs, have fueled an amazing turnaround in their population. Today, they number in the tens of thousands and migrate along the Australian coastline every year. These whales typically travel north from the cold, krill-rich waters of their southern home. During the winter months, they migrate to warmer waters north of the continent to breed.
The spring northward migration starts in April, and these whales generally go back south between August and November. All the new discoveries have led scientists to redefine the geographical boundaries of Humpback Whale breeding territory.
Observations from the Field
This transformative observation was made by Ms. McPhee-Frew, a PhD candidate who moonlights as a tour guide in Newcastle. Just this past summer of 2023, she was the first to encounter a notably young whale while piloting an entourage from the ACA.
“I saw a newborn right at the mouth of Newcastle Harbour,” – Ms McPhee-Frew
Her experiences are consistent with the data collected by other citizen scientists, whale watchers, and local researchers. They show that two-thirds of live Humpback Whale calves sighted were during the 2023 and 2024 migration seasons.
Ms. McPhee-Frew pointed to the importance of citizen engagement in these finds.
“This research wouldn’t have been possible without whale watchers and all their knowledge and experience,” – Ms McPhee-Frew
Nearly all of the data on where calves are being sighted comes from citizen science. This points to the incredible power of public observations for the study of animal patterns.
Implications for Humpback Whale Ecology
Dr. Olaf Meynecke, whale researcher Dr. Meynecke said that although the results were interesting, they were not surprising. As the last piece, he made a call for more systematic studies centered on Humpback Whale mothers and calves born midway through the migration.
“Will it return to the same waters where it was born for reproduction?” – Dr Meynecke
He noted that these results may mean that Humpback Whales have changed how they respond to environmental conditions.
“With an expansion of the population and higher stress on food availability during summer feeding, it may be an advantage to give birth further south,” – Dr Meynecke
These waters would offer improved temperature control for baby whales and much safer, calmer waters with fewer predators like orcas.
The new birthing grounds maybe indicate a more flexible nature to Humpback Whale behavior, calling to question their strong migratory instincts. To address this topic, Ms. McPhee-Frew explored a fascinating question. So are females driven by deep cultural or genetic forces to migrate north, despite the new birth sites?
“Is it that the female is just driven north through some deep either cultural or genetic instinct?” – Ms McPhee-Frew
Conservation Efforts and Future Research
Even as Humpback Whales ride high on the rebound along coastal Australia, conservation laws are still necessary to protect them. For research involving drones, they must remain at least 100 m away from these animals. Many states have more stringent regulations to further reduce impacts.
As we seek to learn more about Humpback Whale migration patterns, responsible whale watching practices become even more crucial. While following the letter of the law, Ms. McPhee-Frew promotes innovative methods to involve the public in decision-making.
“We encourage people to enjoy these lovely animals, provided they’re following the rules that are in place for the whales’ protection,” – Ms McPhee-Frew
The growth in calf sightings contributes significantly to understanding Humpback Whale ecology and behaviors during migrations, emphasizing the role of citizen scientists in marine research. Observers along Australia’s coastlines can further assist researchers by logging their sightings of Humpback Whales, providing valuable data that could shape future conservation strategies.
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