Two stories are filling up my Twitter stream this morning. One is about Horsetail Fall, which, at this time of year, glows orange with the setting sun, and the other is about the alpine chipmunk, a high-elevation resident of Yosemite. What could these two stories possibly have in common (other than Yosemite)?
First, a little background.

Horsetail Fall is one of many tiny, barely noticeable waterfalls in Yosemite Valley, especially when compared to the nearby waterfalls that are much larger and more famous. It flows off the eastern side of El Capitan during winter and spring, and is positioned in just such a way that the setting sun colors it orange in mid to late February (if there’s enough water and not too many clouds). The effect is unusual if not unique, and very cool to see when conditions are right. It’s even more popular because of its comparison to the Fire Fall. (Beginning infrequently as early as the 1870s and recurring on a more regular basis later on, until 1968, park employees would build a bonfire at the top of Glacier Point, then, as it got dark, they would slowly shove the embers over the edge, creating the Fire Fall.) The result was what looked like a glowing waterfall.) Horsetail Fall with the right light looks similar and, better yet, is completely natural.

The alpine chipmunk is one of the species of chipmunks that lives in Yosemite. As the name suggests, this chipmunk lives at the highest elevations of the park. A recent study found that the elevational range of the alpine chipmunk had shrunk (risen) by over 1,600 feet since the 1910s (when it was found as low as 7,800 feet). Since the 1910s, the average temperature in Yosemite has risen by over 5 F°. It’s safe to assume that rising temperatures have pushed these tiny, temperature-sensitive animals higher in elevation because the lower portions of their range have become too warm. Now that their elevational range is smaller, the amount of land they have to live in has shrunk dramatically. I’m not sure of the numbers, but a large portion of the park is at or above 7,800 feet, but only a small portion of the park is at or above 9,400 feet. With such a loss of  habitat, it’s no surprise that this study found that genetic diversity had declined significantly (making the population more susceptible to disease and less able to cope with further environmental change). With (relatively) extreme warming over many more decades, the chipmunk could eventually have its elevational range exist only in the sky, above the highest peaks of Yosemite. But, with loss of genetic diversity, it could become extirpated (locally extinct) much sooner.
So, what does this chipmunk story have to do with Horsetail Fall?

While many people (but hardly any scientists) argue over whether humans are at least partially the cause of climate change, climate change is an observable fact in Yosemite. The impacts of climate change are not limited to the alpine squirrel or some of the other plants and animals that could be impacted with continuing change. Climate change is slowly reducing the majesty of Yosemite’s waterfalls. As average winter snow level continues to rise over the decades, the area of Yosemite getting a snowpack will continue to decline, which means less snowmelt to feed Yosemite’s waterfalls. Spring runoff in Yosemite will be less dramatic (runoff following winter storms might be the best time to see waterfalls). With its tiny and relatively low-elevation drainage area, one of the first victims of this change will be Horsetail Fall, which might rarely flow, even in winter.

Climate change is not only shrinking the alpine chipmunk’s habitat, but also shrinking Horsetail Fall’s already tiny snowpack. When the alpine chipmunk becomes an endangered species, Horsetail Fall and its elusive orange glow may, like the Fire Fall, become just a memory.


Yosemite Nature Notes has some quite excellent videos about Horsetail Fall, snowpack, and climate change:

A week or so ago, one of the park’s wildlife biologists was driving out of Yosemite Valley when she saw a coyote standing in the middle of the road. This isn’t all that surprising: some coyotes know visitors will feed them if they beg by the road (these coyotes don’t realize they’re more likely to get killed by cars, too).

In any case, as she drove up toward the coyote, the coyote refused to move; this is unusual. Finally, she looked over and saw a bear hiding behind a boulder. Then, the coyote and bear sniffed each other. As she drove off, she looked in her rear-view mirror and saw them touching noses.

Bears and coyotes don’t typically tolerate each other much. I wonder why it was different this time.

On my wildlife walk, one of the animals I talk about is ravens, which I refer to as flying bears because they’re so smart.

Well, it turns out that ravens not only are smart but are also empathetic. While it’s long been assumed that animals have no thoughts or feelings, research in recent years has increasingly shown that this assumption is not true. Yet, acts of altruism documented during research are often referred to as “seemingly altruistic behavior,” with explanations that the behavior isn’t truly altruistic because the behavior favors passing on family genes (kin selection) or the altruism is just the returning of a favor (reciprocity).  If you think about it, how many acts of human altruism could be ascribed to kin selection, reciprocity, or an expectation of a reward (in this life or the next)?

In this study, the authors seem to believe that ravens actually feel empathy and they describe the behavior as “altruistic” (not “seemingly altruistic”). The behavior seems to depend on the strength of their relationships. It doesn’t seem that surprising because adult ravens form lasting (lifelong) relationships and do pair bonding activities not unlike those humans do, such as grooming each other, gift giving, and joint acrobatics (perhaps akin to dancing?).

Wired Science

Ravens Console Each Other After Fights

By Jennifer Welsh
May 17, 2010

After ravens see a friend get a beat down, they approach the victim and appear to console it, according to new research.

Orlaith Fraser and her co-author Thomas Bugnyar watched the aftermath of 152 fights over a two year period between 13 hand-reared young adult ravens housed at the Konrad Lorenz Research Station in Austria. What they found was the first evidence for birds consoling one another.

“It’s not a good thing for your partner to be distressed,” Fraser explained. “It’s interesting to see these behaviors in animals other than chimpanzees. It seems to be more ingrained in evolutionary history.”

Read the rest of the article… or read the full journal article on PLoS.

While the research may not be as robust for other animals, it seems like a lot of animals mourn death.


Chimps Understand and Mourn Death, Research Suggests

By Charles Q. Choi
posted: 26 April 2010 12:07 pm ET

Chimpanzees may gather in hushed quiet to watch a fellow ape in her dying moments, and chimp mothers in the wild may carry their infants’ mummified remains for weeks, according to new research on how humanity’s closest living relatives deal with the deaths of those closest to them.

Insights into how chimpanzees respond to the death of one of their own are rare. One such instance came with the final hours of Pansy, a chimp more than 50 years old who lived in a Scottish safari park.

In the days leading up to the elderly chimp’s peaceful demise in 2008, her group was very quiet and moved to sleep near her, the researchers found. Immediately before Pansy died, others groomed and caressed her often. One male chimpanzee, Chippie, apparently tested her for signs of life as she died by closely inspecting her mouth and moving her limbs.

Read the rest of the article…

Studies have shown that people exposed to constant noise are more stressed out. I’m not sure whether that’s true of animals (although I’m not sure why it wouldn’t be), but it does seem that even small amounts of noise might affect how animals interact.

the acoustic ecology institute

NPS study: moderate noise can have major impacts on animals

December 13, 2009

An ongoing research project from the National Park Service Natural Sounds Program is about to publish a groundbreaking paper that outlines the many ways that even moderate increases in human background noise can create major impacts on animals.  The study proposes a new metric for use in bioacoustics research, the “effective listening area.”  This is the area over which animals can communicate with each other, or hear other animals’ calls or movements; as might be expected, animals focus especially on listening for sounds at the very edges of audibility, so that even a small increase in background noise (from a road, wind farm, or regular passing of airplanes) can drown out sounds that need to be heard.  The authors note analyses of transportation noise impacts often assert that a 3dB increase in noise – a barely perceptual change – has “negligible” effects, whereas in fact this increased noise reduces the listening area of animals by 30%. A 10dB increase in background noise (likely within a few hundred meters of a road or wind farm, or as a private plane passes nearby) reduces listening area by 90%.

Read the rest of the article…

Lots of people visit Yosemite and are surprised at the lack of wildlife they find here. Some national parks, like Yellowstone, have many more wildlife viewing opportunities than Yosemite.

In Yosemite, people often notice squirrels and birds. Less often, they notice deer or coyotes, and much less often, they see a bear. So, we say Yosemite isn’t a wildlife park in the way that a park like Yellowstone is.

But, we lie.

California spotted owl in Yosemite West

California spotted owl in Yosemite West

The other night, while driving home, I saw something odd atop a roadside snow pole (the poles that mark the edge of the road for snowplows). After a moment for my eyes to adjust to the dark, I realized I was seeing an owl–a California spotted owl. Yosemite is home to eight different species of owls… but only one kind of deer, one kind of coyote, one kind of bear. And we say Yosemite isn’t a wildlife park!

Indeed, Yosemite hosts at least 165 different species of birds! Plus another 90 that have only been seen a few times.  There are probably fewer than 80 different species of mammals in Yosemite (what most people think of when they think of wildlife). Seventeen of these mammal species are bats (apparently the diversity is in the sky).

So, Yosemite is a wildlife park–but you have to look up to see most of the animals.

Yosemite’s website has more information about birding. It’s a relaxing thing to do (and something you can do wherever you live, although doing it in Yosemite has its perks!)

Several species of animals seem to exhibit forms of culture. Here’s a fascinating article about this:

Hidden Whale Culture Could Be Critical to Species Survival

By Brandon Keim | June 24, 2009 |

Though it sounds at first like a marine biologist’s take on political correctness, respecting the cultural diversity of whales may be essential to saving them.

Scientists are accustomed to thinking of whale populations in terms of genetic diversity. But even when they share the same genes, groups of whales can live in very different ways, raising the possibility that species might be saved even while individual cultures vanish. The tragedy of cultural extinction aside, cultural diversity may sustain the long-term health of Earth’s cetaceans.

Read the rest of the article…

For a long time, biologists believed that animals didn’t have emotions; that they weren’t really conscious. Work in recent years has shown this isn’t quite the case. (Marc Bekoff has written some good books on this topic, such as Minding Animals.)

The New York Times recently had an article about some such research, and it’s rather interesting. It reminds me that animals are a lot more like us than we might care to admit… which also means we’re a lot more like them than we might care to admit.

In That Tucked Tail, Real Pangs of Regret?

Published: June 1, 2009

If you own a dog, especially a dog that has anointed your favorite rug, you know that an animal is capable of apologizing. He can whimper and slouch and tuck his tail and look positively mortified — “I don’t know what possessed me.” But is he really feeling sorry?

[read the rest of the story]