Wildlife

The mountain goat is one of nature’s most skilled mountaineers. The hooved herds make their way through harsh Alpine terrain with relative ease. And they’ve been living with mountain snow since the Ice Age.

According to wildlife ecologist Kevin White, that also means that they live amid avalanche paths.

“And they would have no way of knowing that,” White said. “They can’t login to the avalanche forecasters’ website.”

White is a scientist at the University of Alaska Southeast and the University of Victoria who has been tracking mountain goats to see how they meet their end. It turns out, avalanches are a leading cause of death.

According to a new study published in the journal Communications Biology, snow slides have taken out up to 22% of the goat population in the most extreme years. The research, led by White and collaborators from the University of Alaska and institutions in Montana and Switzerland, shows the scale of that mortality for the first time.

Scientists know a lot about goats’ relationship with snow. Heavy snowfall can bury food or make it more difficult for goats to move around, which can have a negative effect on survival. 

But the role of avalanches has always been unclear, in part because a lot of mountain goat research is conducted in the summer, and in part because avalanche paths are remote and hard to access. 

“Avalanche shoots are often a tangle of alders and Devil’s Club and salmonberry and difficult hiking to get to those sites,” White said. 

White spent nearly 20 years trekking to these locations to do detective work on goat deaths, first with the Alaska Department of Fish and Game and later as a researcher who processed that data with funding from the Alaska Climate Adaptation Science Center.

He spent countless hours hovering above mountainsides in helicopters and small planes, where he first targeted goats from a distance with tranquilizers before fitting them with a GPS collar. 

White collared 421 goats in Klukwan, Lynn Canal, Baranof Island and Cleveland Peninsula. Then, he waited for them to die.

Some caught disease. Some couldn’t get enough food. Some were caught by predators. A lot of those deaths were the youngest and the oldest, the most vulnerable in the population.

“But in the case of avalanches, it’s essentially selecting individuals out of the population at random,” White said.

Meaning avalanches can take out goats that are in the prime of their lives, including females who are the perfect age for reproduction. That can be a tough loss for local populations. 

According to University of Alaska Southeast snow scientist Eran Hood, a co-author on the study, the new research also revealed a surprising coincidence. Avalanche-prone slopes are usually between 30 and 45 degrees — shallow enough for snow to accumulate, but steep enough for gravity to eventually pull it down. 

“Well it turns out that the most common slope angle for mountain goat habitat is in the forty degree range,” Hood said. “So basically, the range of terrain where they like to hang out is right in the center of the most common slope angle for avalanches.” 

If goats are risking their lives by spending time in avalanche terrain, the researchers believe there must be an evolutionary trade-off that offsets the enormous loss of life. Figuring out what, precisely, it is will require more research. 

Avoiding predators who can’t make it up that high in the mountains is one possibility. Another is that snow slides unbury the food. 

“Those slopes may green up sooner in the spring. And the first flush of green vegetation has really high nutritional quality,” White said. “In some areas appears to coincide with when female mountain goats are giving birth to their kids, which requires a lot of energy.”

On average, avalanches caused 8% of annual mountain goat deaths. In some years, they caused none. And in the most extreme years, in the most extreme locations, they caused 22% of deaths in the population.

Avalanche risk varies a lot from year to year, Hood said. So it’s important for wildlife managers to keep that in mind when setting annual hunting limits. 

“If you knew in a winter that 22% of the population got taken out by avalanches, you should certainly be considering that in decisions you make with regard to harvest,” he said.

And as climate-sensitive mountain goats adapt to rapidly changing high mountain conditions, with more temperature variability and changing snow patterns, their relationship with avalanches may continue to change too.

On a recent sunny Friday in Juneau, Lindsey Bloom was eager to get outside and enjoy the spring weather. 

“I was like ‘Okay, I’m just going to go for a little paddleboard. I’m gonna just watch the sun sparkle on the water and that’s gonna like light me up from just a day of emails,” Bloom said.  “I mean it just seemed so … just so benign.”

At Bloom’s home on Lena Loop Road, the ocean is practically part of the backyard. She goes paddle boarding often, but this particular afternoon was far from routine. 

A few minutes into her paddle, she spotted a pod of orcas — four or five of them — out on the horizon. She took a video to send to her parents. But then she spotted something in the water.

“I looked down, and I saw this white color coming up from under. And I was like, ‘Huh, a dead halibut is floating belly up under my paddleboard,'” Bloom said. “And then her fin sliced up out of the water, and she exhaled.”

Before she knew what was happening, a large female killer whale lifted Bloom’s paddleboard up out of the water.

“And at that moment it was like terror,” Bloom said.

In Juneau, people share the land with bears, eagles, whales and more. It’s one of the reasons people love living here, but earlier this month, a handful of close encounters with a curious killer whale reminded people of the city’s wildness.

As her board was bobbing, Bloom stood frozen with fear as the whale circled her a half dozen times, diving down under her and then twisting around to look up at the surface. Bloom says she made eye contact with the young orca.

“And then I started talking to her, I was like ‘I have kids. Please go away.’”

Eventually, the whale did go away and Bloom was able to make it to shore safely, though she was shaken up.

Later that afternoon, the whale sidled up to Matt Musslewhite’s red skiff. He was sailing near Point Louisa, just a few hundred yards down the shoreline. When he saw the whale’s black fins glistening on the surface of the water, he cut the engine to let it safely pass.

“Instead she just turned and charged right up to me and ran her dorsal fin down the side of the boat, and circled round the boat a couple of times,” Musslewhite said. “Then (she) took off to join the rest of her pack.”

Musslewhite said the whale was gentle.

“I think she might have been a teenager, a curious teenager just coming to check out my boat,” he said.

Marine Mammal Specialist Suzie Teerlink with the National Oceanic and Atmospheric Administration said there were at least three reports of close encounters with this orca, who was in fact a teenager, on April 26. But no one has been able to identify the specific whale or the pod it belongs to. 

 

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In a social media video taken by another paddler, the whale splashes around, making circles before poking her head out and spraying from her blowhole. 

Teerlink said that most of the time killer whales will keep their distance when they come across people.

“At the same time, they’re really smart, really curious animals,” she said. “They’re at home in their environment and if something strikes their curiosity they might push that envelope.”

There are no local reports of killer whales pursuing humans to hurt them. But there have been reports of pods attacking boats in other parts of the world. 

Teerlink says it’s best for both whales and people to keep our distance.

“We don’t want killer whales, you know, individuals to get too comfortable going up to people to get too comfortable going up to people,” she said.

So if you encounter a whale yourself, the best thing to do is move away as quickly as possible.

Orcas tend to migrate over large areas relatively fast. So while they’re pretty common in Juneau, the curious teenage whale and her pod have probably left the area by now.

Bloom said learning more about orca’s curious nature has calmed her fears a bit. She feels there’s an inherent stigma around the meat-eating marine mammals, which made her more afraid.

“We call them killer whales,” Bloom said. “Why do we have to call them that? Because it makes them scarier than they need to be.”

And in the week since the close encounter, she’s come to appreciate it, in a way.

“This is so Alaska,” Bloom said.  “All you gotta do is walk out your front door, and it’s like epic.”

But for now, she plans to paddleboard on Auke Lake instead. 

White-tailed deer have expanded their range in North America over many decades. Since the early-2000s, these deer have moved north into the boreal forests of western Canada. These forests are full of spruce and pine trees, sandy soil and freezing winters with lots of snow. They’re basically your typical winter wonderland in theory — but actually living there can be harsh.

Ecologists haven’t known whether a warmer climate in these forests is drawing deer north, or whether human land development might play a bigger role.

“Human land use and climate change are both leading causes of biodiversity loss. But more often than not, those two things are highly intertwined, and it’s really tricky to tell which one is the root cause — or if it’s both,” Melanie Dickie, a wildlife biologist at the University of British Columbia, Okanagan says. “We really need to know which one it is so we can have a better idea of what to do about it.

Dickie described these deer as an “invasive species.” Because more deer in these forests can have an impact on other species like boreal caribou. With deer come more predators like wolves. While deer are able to cope with living alongside predators like wolves, caribou are not. Dickie says they’ve evolved to mostly just avoid areas with lots of predators. And that gets tricky when there are more wolves around.

She also says that deer are really just one piece of the puzzle for boreal caribou — but having more information about what exactly is driving deer expansion helps her and other researchers figure out where to start when it comes to restoring land and protecting wildlife.

Read the study in Global Change Biology

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On April 1, a young humpback whale was found tied up in what was likely fishing line and anchored down in a busy area in Iliuliuk Bay. Four days later, a group of whale entanglement experts carefully cut the line wrapped around the humpback’s mouth and tail.

Ed Lyman, an entanglement response coordinator for the Hawaiian Islands Humpback Whale National Marine Sanctuary, thinks the whale was a two-year-old male who got hogtied while feeding in the area.

“(He) gets the line wrapped up in the mouth, panics, and twirls up,” Lyman said. “Suddenly, he’s got it on his tail as well — between the mouth and tail.”

It is unclear what type of fishing gear weighed down the 30-foot whale, but it gave enough slack for him to come up for air.

Lyman said the rescue process takes time. He has participated in 120 whale entanglements and said even though entanglements can be life-threatening for whales, they are not an immediate threat. He said whales are large animals, and disentangling can be deadly if not done carefully.

“So they have time on their side; we have time on our side,” Lyman said. “I’ve never been involved in entanglement where the animals died in a day or two.”

The Alaska Department of Fish and Game in Dutch Harbor received a call about the entangled whale from locals who noticed that the humpback was breathing and unable to move freely.

It was then reported to marine traffic in the area. The U.S. Coast Guard in Alaska and the nonprofit organization Marine Exchange of Alaska posted a digital map displaying the entangled humpback, warning vessels entering the harbor to avoid the hazard.

Asia Beder, the state’s assistant area management biologist for Dutch Harbor, appreciated the patience shown by the community of Unalaska. She says it played a vital role in the successful rescue of the humpback whale.

“I know this was a very emotional story and event for the community,” she said. “By giving us reports, keeping the distance, and allowing us time, I think that created this into a success story.”

Local ADFG staff received expert advice on capturing footage of the whale entanglement using a camera attached to a pole. They said it helped whale experts determine specialized tools required for the rescue operation.

Sadie Wright, a large-whale entanglement response coordinator for the National Oceanic and Atmospheric Administration, is based in Juneau and has participated in 15 whale entanglements. She said whales can sometimes free themselves from entanglements. However, based on the photos and reports collected from the Unalaska community, it was clear that this whale needed help.

“It was a life-threatening entanglement, and we determined it needed an advanced response,” she said. “So reporting is essential.”

The actual rescue took two days. On a boat, local Fish and Game biologists and visiting whale experts gathered data from specialized tools. They floated around the whale and sometimes over it. The team used a large pole with a hook knife at the end of it, and a camera attached, so they could see in real time where the knife was cutting the rope underwater.

“We knew which line we wanted to cut first, and then second, to try to encourage the rope to then come off by itself to slide off the animal,” Wright said, “which eventually happened.”

Lyman said the whale cooperated during the rescue and even seemed curious at times.

“It would almost rise up a little bit more and lean over a little bit,” he said. “Like, ‘What are you guys doing? Why are you here?’ You know, that kind of thing.”

After the whale was cut loose, the team followed it out of the bay and into the Bering Sea. They said the whale looked good and was swimming normally. Once it got further out, it picked up some speed and took a nice deep dive. Lyman said there’s a good chance the humpback will be fine.

“You know, I would almost bet on it, and I’m not a betting man,” he said.

The whale rescue team recommends not putting unnecessary objects in the water and reducing the use of floating lines to prevent whale entanglements.

The young humpback whale is currently identifiable with a string-like mark on its dorsal fin, which the team thinks is from when the whale was trying to break free from the gear.

A humpback whale is now free in Unalaska after being tied up for at least four days. The entangled whale was first reported on Monday evening in Iliuliuk Bay.

Officials from the National Oceanic and Atmospheric Administration and the Alaska Department of Fish and Game were able to free the whale Friday morning. The team included Ed Lyman, a large whale entanglement response coordinator from Hawaii, and Sadie Wright, a biologist from Juneau. They both flew into Dutch Harbor Thursday morning and worked on detangling the whale until late Thursday afternoon. They resumed work the following morning at sunrise and freed the whale around 10 a.m. The whale swam out of the bay and into the Bering Sea.

Julie Fair, a spokesperson for NOAA, said additional information about the rescue will be provided later.

During the entanglement process, U.S. Coast Guard personnel were present on a nearby boat, and officials used a drone during the operation.

Across the animal kingdom, menopause is something of an evolutionary blip. We humans are one of the few animals to experience it.

Sam Ellis, an animal behavior researcher at the University of Exeter, says that this fact isn’t so surprising.

“The best way to propagate your genes is to get as many offspring as possible into the next generation,” says Ellis. “The best way to do that is almost always to reproduce your whole life.”

So perhaps it’s more surprising that a handful of animals ever evolved this trait.

Ellis and his team at the University of Exeter have recently published a study in the journal Nature that sheds light on how this trait may have evolved in toothed whales. There are five species of toothed whales that undergo menopause — short-finned pilot whales, false killer whales, killer whales, narwhals and belugas — making it the type of animal that is known to have evolved menopause most frequently.

A winning intergenerational survival strategy

The rare nature of menopause across animals doesn’t mean, however, that it’s a bad strategy.

Ellis and his team, in partnership with the Center for Whale Research, looked at the welfare and longevity of menopausal toothed whales versus non-menopausal toothed whales. They found that not only do the menopausal female whales live, on average, 40 years longer than females of other species — these females also live longer than the males of their own species.

Researchers think that reason for this could be tied to reproductive competition.

Generally, if a mother and her daughter are both reproducing and living in the same group at the same time, they’re competing for the same resources. “There’s a limited amount of food around and you’ve got to choose who you give it to,” says Ellis. “And so there’s competition.”

According to the grandmother hypothesis, menopause could help avoid that competition. Older females can better protect their offspring — and better ensure their genes are passed on — by instead helping to protect and provide for their children and grandchildren.

Why toothed-whales?

For menopause to evolve, very specific circumstances are needed.

First, females must spend their lives in close contact with both their immediate offspring and their grand-offspring in order to create this reproductive competition. In menopausal toothed whales, not only do the lifespans of females overlap with their direct kin and grand-kin, they can continue to interact with these generations throughout their lives — as observed in killer whales, for example.

Second, the females must have an opportunity to help their families after they can no longer reproduce. There are various ways that older female toothed whales can provide intergenerational help. They might share food with relatives, share their knowledge of the ecosystem and lurking dangers, or even help babysit their grand-calves.

All of this behavior has been documented in toothed whales. While much of whales’ social structures are still unknown, beluga whales and narwhals are usually called “matrifocal,” meaning the oldest female takes charge.

Essentially, menopause helps create a social role of the whale grandmother. She sticks close to her descendants, helps them in times of need and shares her wisdom.

Ellis says that while scientists can’t say for sure, humans likely evolved menopause for similar reasons. “It looks like there’s only one pathway for the evolution of menopause.”

He and his team plan to dive deeper into intergenerational help – instances they see in these whales and other menopausal species.

But for now, this research reveals some of the similarities we humans share with creatures that at first glance seem quite different from us. Not only are both animals menopausal, we’re also long-lived — with grandmothers that play a large role in our social structures.

Curious about other animal behavior mysteries? Email us at shortwave@npr.org.

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