Southern right whales that set off a month early arrive with the ones that leave late
University of Auckland researchers found 21 tracked southern right whales on two routes reached feeding grounds at about the same time. The data are tracks with no experimental control, so they show what the whales did on each route.
The Scientist · Science desk
Key figures: mean travel time was 64 days for the long trip and 42 days for the short one. 21 southern right whales were tracked.
| Figure | Value | Note | Claim |
|---|---|---|---|
| Mean travel time, long route | 64 days | 6 | |
| Mean trip, short route | 42 days | 6 | |
| Whales tracked | 21 whales | 1 |
What happened
- The whales were followed from their winter home in the Auckland Islands, in subantarctic New Zealand, to feeding grounds south of Australia.
- About half took a direct route westward, and the rest went much farther south before turning north in an L-shaped journey.
- Whales on the long route set off roughly a month sooner and swam at a slower pace. The ones that started late used the shorter route and were slightly quicker.
- Mean travel time was 64 days for the long trip and 42 days for the short one.
Why it matters
- What it limits constraint Arrival at the feeding grounds is the same for both routes, so a count of whales on arrival cannot tell you which path an animal took or when it left.
- Who has to decide decision Anyone modelling this population has to let a whale change route between years, since the researchers' example female did.
- Who's exposed exposure The resilience case for a recovering population is Carroll's inference from flexibility seen in current conditions. The tracking did not test it.
The two means can be checked against each other. The long-route whales spent 22 days longer on the water [9] and left about a month before the direct group [5]. Taking a month as 30 days, that is a head start of about eight days once the extra travel is subtracted [12]. Phys.org's account of the Proceedings of the Royal Society B paper [2] says only that both groups arrived at roughly the same time [4], and a gap of a week could sit inside that description. The account does not include route lengths, arrival dates or the number of whales that switched routes between years.
The sample is small. About half of the 21 whales took each route [3], so each group is roughly ten animals [10], and a few animals can move a group mean. The design is observational. Nobody assigned a departure date or a route, so the tracks show an association: early departure and slow travel go together on the long route.
Lead author Leena Riekkola suggests the whales may be balancing priorities as people do on a road trip, with some conserving energy and others making up for lost time [7]. A track records only position and timing. We think the timing match is the firmest finding in the study, because it comes straight from the tracks.
The researchers' example of an individual cuts against sorting whales into fast and slow types. One year a female might delay migration so her calf can grow bigger and take the shorter route, then take the longer route the next year when travelling alone [8].
The navigation result is a correlation. The whales' movements lined up with major ocean currents, underwater features and subtle variations in Earth's magnetic field [11]. A whale carried along by a current would line up with it without sensing it.
The researchers draw a conservation point from the flexibility: it could be good news for this recovering population as the climate changes [14]. Associate professor Emma Carroll said: "A population that can adapt its behavior has a better chance of coping with changing seas." [13]
What to watch
- The full paper's arrival dates and route lengths, which would show whether the long-route group lands a week ahead or level with the direct group.
- More years of tracking, to count how many individual whales switch between the long and direct routes.
- Any test of whether whales respond to currents or magnetic variation, since the study reports alignment with them.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence55
- Adoption
- Not scored
- Hype gap+10
- Incentives
- Not scored
- Confidence50
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
Scientists from the University of Auckland and international partners tracked 21 southern right whales from their winter home in New Zealand's subantarctic Auckland Islands/Maungahuka to feeding grounds south of Australia.
- [2]
The findings are published in the journal Proceedings of the Royal Society B: Biological Sciences.
- [3]
About half the whales took a direct route westward. The others headed much farther south before turning north again, creating a giant L-shaped journey across the ocean.
- [4]
Despite the different travel styles, both groups reached their feeding grounds at roughly the same time.
- [5]
The whales taking the longer route left about a month earlier and traveled more slowly, while the late starters took the shorter path and moved a little faster.
- [6]
The mean travel time was 64 days for the long trip and 42 days for the short one.
- [7]
Lead author Leena Riekkola says the findings suggest whales may be balancing different priorities, much as people do on a road trip; some may be conserving energy, while others appear to be making up for lost time.
- [8]
One year, a female might delay migration to allow her calf to grow bigger, taking the shorter route, but the next year, when traveling alone, take the longer route.
- [9]
The long-route group's mean travel time was 22 days longer than the direct group's.
- [10]
With about half of 21 whales on each route, each group is roughly ten animals.
- [11]
The whales' movements lined up with major ocean currents, underwater features and subtle variations in Earth's magnetic field.
- [12]
Taking 'about a month' as 30 days, the long-route group's head start exceeds its extra travel time by about 8 days, so on these rounded figures it would arrive about a week ahead.
- [13]
"A population that can adapt its behavior has a better chance of coping with changing seas," said associate professor Emma Carroll.
- [14]
The researchers say flexibility could be good news for this recovering population as the climate changes.
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Sources
1 independent publisher whose own reporting we read for this story.
- phys.orgWhales take different routes but still reach dinner on time
1 article · October 16, 2026
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- Emma CarrollFollow
- University of AucklandFollow
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