AILSA CHANG, HOST:
A new study of brown bears in Sweden has found a surprising trend - mother bears are spending longer with their cubs than they used to. As NPR's Rebecca Hersher reports, hunting policies have a lot to do with the change.
REBECCA HERSHER, BYLINE: Brown bears are large, dangerous and shy, so the best way to study them is to tag them.
FANIE PELLETIER: We can recognize them because they wear a GPS collar and tags. So it's possible to link what happened to a bear, let's say, early in its life and then what happened to it later in its life.
HERSHER: Fanie Pelletier studies predators at Sherbrooke University in Quebec. We talked over Skype. She's been studying bear motherhood for years. Right around this time of year, mother bears emerge from their dens with their cubs. This is when the real child rearing begins. And how long it takes depends.
PELLETIER: They care for their cubs either 1 1/2 year or 2 1/2 years. So there's variability in how long a female will stay with her cubs.
HERSHER: But Fanie analyzed decades of data and found more and more bear mothers are choosing to spend that extra year with their young, a 30 percent increase since 2005. The reason?
PELLETIER: So females and cubs, they are protected from hunting.
HERSHER: Sweden, where the data she analyzed came from, is one of many places where it's illegal to shoot a bear with cubs. You might think mothers are sticking around to protect their kids, but it's actually the other way around.
PELLETIER: If you leave your cubs at one year and a half, then you become a target. But if you stay for a bit longer with your cubs, then you're protected an extra year. So there's a clear benefit of being longer in family groups.
HERSHER: This isn't the first time a hunting policy has had unintended consequences for animals. Preferentially harvesting larger fish has led some species to mature at smaller sizes. Rams hunted for their large horns eventually develop smaller ones. Pelletier says changes like that are a reminder that hunting rules can have profound effects on the animals left behind. Rebecca Hersher, NPR News.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.