How sled dogs and pets respond when the clocks change
Many people struggle with the biannual time shift caused by daylight saving time, often finding it difficult to adjust to the sudden change in their daily routine. However, humans are not the only ones affected. A recent study conducted by researchers from the University of Toronto has revealed that sled dogs in Ontario, Canada, also experience noticeable disruptions when the clocks change, particularly when they “fall back” in autumn.
The study, which was published in the journal PLoS One, examined how the time shift impacted sled dogs whose daily lives are structured by a strict schedule. Researchers placed movement sensors on a group of sled dogs in Ontario’s Haliburton Forest Wildlife Reserve and found that, the morning after the clocks went back an hour, the dogs were active and moving around an hour earlier than usual. This shift indicated that the dogs’ internal clocks had not adjusted immediately to the new schedule.
Interestingly, pet dogs of the same breeds—Siberian Huskies and Alaskan Malamutes—showed no such effect. Unlike their working counterparts, these pet dogs appeared to sleep through the extra hour without showing signs of restlessness. The contrast between the two groups suggested that routine and environmental factors played a significant role in how animals responded to human-imposed schedule changes. Dr. Lavania Nagendran, one of the lead researchers on the study, admitted that she was surprised by the results. “I wasn’t expecting any differences between the two groups of dogs,” she said. “But it was fascinating to see how the sled dogs were so precisely aligned to their routine.”
The research is part of a broader study investigating behavioural differences between wolves and domestic dogs. Co-lead researcher Ming Fei Li explained that their team is interested in understanding whether wolves can also adapt to schedule changes and whether this ability evolved naturally in canines or was developed through domestication. “Not all animals can simply adjust their schedules in response to human influences,” Li said. “We want to determine if flexibility in daily activity is something that predates domestication or if it was imposed on dogs by humans.”
Much of the existing research on the effects of daylight saving time has focused on human health and sleep patterns. Studies have indicated that the time shift can lead to disrupted sleep, increased fatigue, and even a short-term rise in traffic accidents due to drowsy driving. However, this study is the first to examine how domestic dogs react to the biannual time change.
The study was conducted in 2021. The researchers fitted motion trackers onto 25 sled dogs and 29 pet dogs in or near Ontario. Participants, the pet owners, kept detailed notes of their dogs’ behaviour and returned the data to the research team. “They were amazing,” Li said of the pet owners. “They asked great questions, followed our instructions carefully, and provided really useful data.” The data revealed that sled dogs, whose schedules were dictated by their handlers, found the shift jarring. Prior to the time change, their human caregivers arrived at sunrise to feed them and begin their daily routines. On the morning following the shift, however, the sled dogs were up and active an hour before their handlers appeared, seemingly confused by the delayed start to their day.
Despite this initial disruption, the sled dogs quickly adapted. By the second day, most of them had realigned their activity to match their handlers’ new schedule. This quick adjustment suggests that while they are highly attuned to their routines, they are also capable of flexibility once a new pattern is established. In contrast, pet dogs did not show the same level of disruption. Despite anecdotal reports from pet owners claiming their dogs become restless or demand food earlier after the time change, the study found no measurable difference in pet dogs’ activity levels. They appeared to adjust effortlessly to the new schedule, possibly because their daily routines were less regimented than those of working sled dogs.
One key takeaway from the study is that working dogs, such as sled dogs, may benefit from a gradual transition when adjusting to time changes. While this study focused on sled dogs and pet dogs, it raises broader questions about how other animals with structured routines may react to daylight saving time. Farm animals, zoo animals, and even service dogs might experience similar disruptions. Future research could explore whether gradual transitions help other species adjust more smoothly to schedule changes.
