Climate change is not only affecting humans and our surrounding environment, but it’s also affecting animals… particularly those in the Arctic where the climate is shifting more rapidly.
A recent study published in Science magazine analyzed data from more than 200 research studies focused on the movement of Arctic animals (data pulled from the Arctic Animal Movement Archive). Nearly a hundred species were analyzed from 1991 to present, tracking their migration in combination with rainfall, snowfall, temperature and topographic patterns observed by NASA.
The research pointed to three examples – the migration of eagles, the mating/reproduction season of caribous and a study of several predator/prey species – and how each was showing a change in normal routine due to shifts in climate.
In partnership with NOAA, data collected from 1991 to 2019 analyzed when eagles left their winter grounds to fly north for the summer. Researchers found that, on average, the migration started about half a day earlier each year, culminating to a two-week shift in migration over the +25 year study.
This earlier than normal migration raises concern for some eagles to miss out on mating and others to reach their summer grounds before their food source arrives.
Normally, caribous mate in the fall and have their offspring in the spring when more food is typically available. But new analysis now shows that caribou populations living in the northern Arctic are having their offspring earlier to line up with their changing environment (warmer temperatures in late winter / early spring). However, southern Arctic caribou populations seem to remain on their “normal’ schedule.
This discrepancy in populations coincides with the fact that the northern Arctic is experiencing more rapid shifts in climate compared to the southern Arctic.
Predator / prey trends
When looking at the trends of several different species of predators and prey (black bears, grizzly bears, moose, caribou and wolves), researchers found mixed results. Moose and wolves showed less movement in winters with higher snowfalls… while increased rainfall didn’t seem to cause any significant change in movement. Other species showed more movement during warmer summertime temperatures.
The concern centers around the idea that different responses to climate change between predators and prey can mean a shift in migration, food availability and hunting patterns. Study analyzers say the trend needs to continue to be monitored.
The research points to different responses of Arctic animals to climate change – some benefiting while others are harmed. Similar to the impacts of climate change on human populations, the impacts to animal populations are not equal and nor is the response.
Animals follow a natural schedule of when to mate, migrate, hunt, etc. by following seasonal cues. When those cues are disrupted (ex. warmer winters, extreme dry spells, etc.), there are trickle-down effects in their ecosystems. But some of those effects are still unknown… and researchers say further analysis and monitoring needs to be done.
For more information on the Arctic animal migration study, click here.