Seals playing a video game reveal how they find their way
The world's harbor seals (Phoca vitulina) are masters in seeing through the cloudy coastal waters they call home. Equipped with dexterous whiskers, these pinnipeds use a suite of senses to navigate their surroundings with ease. Harbor seals may also use an important part of their vision to determine which direction they are moving, even with such an opaque view of the world.
Now, we might know a bit more about how they can tell which direction they are heading. New research involving a simulated swim finds that the particles in cloudy water moving across the retina at the back of the seal's eye can tell them which way they are moving. The findings are detailed in a study published May 29 in the Journal of Experimental Biology.
Harbor seals are commonly found along the eastern and western coasts of the United States. Adult harbor seals are about five to six feet long and they 'haul out' (aka rest) on various rocks, reefs, beaches, and glacial ice when not at sea. This coastal lifestyle means they must navigate in some very busy and murky waters in order to survive.
[ Related: Arctic seals have special noses. ]
'We wanted to know whether harbour seals can determine their heading from optic flow fields – the pattern of motion on the retina generated as a seal moves past visible objects, including particles in the water, in their surroundings,' Frederike Hanke, a study co-author and neuroethologist at the University of Rostock in Germany, said in a statement.
To examine this, Hanke and the team essentially set up an arcade for seals with a gaming challenge. They designed three different computer simulations to show three captive seals. One simulated moving through the open sea, with dots streaming towards the viewer out of the screen. The second used a plane of dots rushing towards the viewer to simulate the seabed passing below. The third emulated the surface of the sea flowing above the viewer's head using another plane of dots.
The team then trained three seals–Nick, Luca, and Miro–to shuffle into place in front of a large screen and showed them the simulations. They were encouraged to indicate which side they were moving towards while watching the simulations (left or right) by touching a red ball with either side of their heats. In return, they were given sprats as a reward.
According to Hanke, Nick and Luca were gaming veterans and picked up this new task with ease. Miro was a novice, but he was reportedly a very open-minded seal, and 'coped with all new situations easily.'
Once the seals were comfortable with the game, the team kept track of the animals' choices as they watched the dots in the simulations. The simulations appeared to show that the seal was heading in a direction that was 22, 18, 14, 10, 6 or 2 degrees to the left, or in similar positions to the right. The team then plotted the animals' successes and mistakes, as the seals indicated which direction they believed they were travelling in during the simulations.
'These are living animals, not robots,' said Hanke. 'Errors are most likely due to inattentiveness or sometimes a drop in motivation.'
When the team plotted the seals' successes, it was clear the animals were capable of determining which direction they were travelling based on the dots streaming in their view, the way that particles would look while they were really swimming. Even in faint lights, the seals appear to be able to use their vision to take advantage of cloudy water to determine which direction they are travelling based on the motion of objects and particles in the water going past their eyes.
In future research, the team is hoping to find out whether they use this same visual effect to determine how far they have travelled.
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Newsweek
3 hours ago
- Newsweek
Scientists Investigate as Whale Deaths Surge in San Francisco Bay
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. A total of 15 whales, including 14 gray whales and one minke whale, have died so far in 2025, according to a joint press release from California Academy of Sciences and the Marine Mammal Center. "The reason or potential reasons behind the massive spike in sightings this year are still being investigated by researchers," the release said. The latest death, a gray whale found in the San Francisco Bay Area on Wednesday, marked the sixth whale death in as many days. Newsweek reached out via email to the California Academy of Sciences and the Marine Mammal Center on Saturday during non-working hours for more information. Why It Matters There has been "unusually high number of sightings" of whales in the region this year but there has also been an increase in deaths. The whale population has seen a 45 percent decrease since the 2019- 2023 Unusual Mortality Event (UME), according to the release. A record-low number of newborn whales was also seen this year, causing concern among researchers for the long-term outlook for the North Pacific gray whales, following the second UME in a 20-year period. "These whales basically left the Arctic with a half tank," Giancarlo Rulli, a spokesperson for the Marine Mammal Center in Sausalito, recently told about the other deceased whales discovered in the region. "The food sources that they were normally accustomed to eating that were highly nutritious for this massive, 10,000–12,000-mile journey, had moved farther away due to climate change, and as a result, these whales were left to forage on food matter that was much less nutritious." What To Know The whale on Wednesday was found near the Alamere Falls in Point Reyes National Seashore, the joint release said, which is about 30 miles northwest of San Francisco. While some of the deceased mammals have been necropsied, others have either been too far decomposed or stranded in areas that are inaccessible, making it difficult to pin these deaths on one similar cause. While it is not unusual to see whales in the region as they migrate, the number of deaths is the highest it has been, including in 2019 when 14 whales were found deceased in the UME, according to the release. The number of deaths currently matches the record of 15 for all of 2021, the release said. At least three of these deaths have been attributed to suspected vessel strikes, but others remain undetermined. The whales that have been spotted alive have been observed to be either regular size or emaciated. There are a total of 33 confirmed gray whale sightings in the San Francisco Bay this year, compared to only six seen last year, with about a third of those whales remaining in the bay for about 20 days. Whale carcasses have been found as far north as Alamere Falls, as far west as Farallon Islands and as inland as Berkeley. Beachgoers look at a dead juvenile Humpback Whale that washed up on Baker Beach on April 21, 2020, in San Francisco. Beachgoers look at a dead juvenile Humpback Whale that washed up on Baker Beach on April 21, 2020, in San Francisco. Photo byWhat People Are Saying The California Academy of Sciences and partners at The Marine Mammal Center said in the press release: "With San Francisco Bay serving as a shared space for commerce and increased gray whale activity, experts at the Academy and the Center note it's vital that all boaters—from large commercial vessels to sailboats—be 'whale aware' and continue to slow down. Gray whales often have a very low profile in the water that can make them difficult to sight, unlike other coastal whales like humpback whales." What Happens Next The results of the necropsy on the whale found on Wednesday are still pending, complicated by a number of factors due to "inaccessible locations that hinder full post-mortem investigations, as well as poor tissue quality from advanced decomposition, and the lack of available locations to tow for further investigation." Meanwhile, the whales that are alive are expected to be in "the bay for another one to two weeks before continuing their annual northern migration to arctic feeding grounds," according to the release. If people do see whales, they can report them through an app called Whale Alert or the Marine Mammal Center website. Sightings of dead whales should be reported to the Academy's department of Ornithology and Mammalogy.
Yahoo
7 hours ago
- Yahoo
Scientists prep bold experiments to fight Arctic phenomenon with global implications: 'Dramatic changes'
A team of climate researchers and engineers is working together with local Arctic communities to implement bold new strategies to address melting sea ice. In a recent article for The Conversation, Shaun Fitzgerald, Director of the Centre for Climate Repair at the University of Cambridge, divulged takeaways from his recent trip to Cambridge Bay in Northern Canada. He visited the region with two projects, Real Ice and Arctic Reflections, both of which aim to slow down the loss of sea ice through experimental strategies. "The dramatic changes in the Arctic warrant investigation into interventions that could have an impact sooner than cutting emissions or removing greenhouse gases," Fitzgerald explained. Sea ice plays a crucial role in temperature regulation globally. With changing temperatures, this delicate balance between warming and cooling of the Arctic has been thrown off balance, causing sea ice to melt more rapidly than it can refreeze in the colder months. Arctic Reflections notes that rising global temperatures have "reduced the Arctic sea ice volume already by 75% over the last 40 years." The ramifications of melting Arctic ice impact more than just the local communities in the far north — this phenomenon has global implications. More melted sea ice means more water in the ocean, which means higher tides during extreme weather events, disrupting food systems with habitat loss for certain animals, and even prompting an increase in the spread of disease. A study published this year even asserted that Arctic sea ice melting is contributing to changing weather patterns in other parts of the world. The team Fitzgerald worked with in Cambridge Bay has three bold concepts to combat the rapid deterioration of the polar ice caps. The first promotes ice growth by pouring seawater onto the surface of sea ice. The second uses snow as an insulator and floods it to create a solid ice sheet that promotes more freezing underneath. The third addresses melt ponds that form in the summer by drilling into them to drain them, leaving reflective ice at the surface to protect the sea ice below. These experiments are educated hypotheses by the team based on mathematical modelling, lab experiments, and smaller field experiments. Should the government be able to control how we heat our homes? Definitely Only if it saves money I'm not sure No way Click your choice to see results and speak your mind. "The goal is to gather essential real-world data to rigorously assess if this intervention warrants further consideration," Fitzgerald explained. While initial results have been inconclusive, the field experiments have been encouraging. But Fitzgerald concluded that big swings like these experiments are an important step toward the ultimate goal of preserving the global climate. "With slow progress [in combatting global temperature increases] over the past few decades, additional measures may buy us time," he asserted. Join our free newsletter for good news and useful tips, and don't miss this cool list of easy ways to help yourself while helping the planet.
Yahoo
a day ago
- Yahoo
Mystery as six gray whales found dead after unusually high influx into San Francisco Bay
Six gray whales have died in the San Francisco Bay Area region in the last week, officials have said. With the additional deaths, the total number of stranded whales this year has reached 15. Of those, 14 are gray whales, according to the California Academy of Sciences and partners at The Marine Mammal Center. 'In 2025, 14 gray whales and one minke whale have died in the greater San Francisco Bay Area region, with the cause of three of the gray whale deaths determined to be suspect or probable vessel strikes,' the academy wrote in a press release Thursday. 'The Academy and partners at the Center have not responded to this many dead gray whales since the height of the Unusual Mortality Event in 2019 (14 individuals) and 2021 (15 individuals).' However, the cause of the deaths of the other whales who died between May 21 and Wednesday are undetermined. Those animals died in multiple locations, including Berkeley, Point Reyes National Seashore, and Alcatraz. 'Necropsy response efforts and data collection have been challenging for a number of cases due to inaccessible locations that hinder full post-mortem investigations, as well as poor tissue quality from advanced decomposition, and the lack of available locations to tow for further investigation,' the academy noted. However, there have also been an unusually high number of sightings around the bay, including 33 individual gray whales. That's more than five times the number of whales that were sighted last year. Of those, approximately one-third have stayed in the Bay Area for at least 20 days, some of which were emaciated. Researchers are still working to determine what's driving the massive spike in sightings, and it is expected that gray whales will remain in the area for another one or two weeks before continuing their annual northern migration to feeding grounds in the Arctic. Dozens of gray whales have died along Mexico's Baja California peninsula since the year's start, and only five mother and calf pairs were identified in Laguna San Ignacio, where wintering whales gather. One of the main causes of death for whales on both coasts are vessel strikes, and the academy and the center pointed out gray whales can be even tougher to spot in the water than humpbacks and other coastal whales. To reduce the risk, they've altered ferry lanes based on sighting data and increased communication via the U.S. Coast Guard, so boaters can be 'whale aware.' If people do see a whale in the bay, they can report the sighting using the Whale Alert app, and people who find dead marine mammals are asked to contact the Academy's department of Ornithology and Mammalogy.
