Wildlife


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

LiveScience

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…

Yesterday, I saw a sow with two yearlings who we’ve probably never seen before (and certainly haven’t captured before–they were untagged). While they may not realize it yet, the time these yearlings have with their mother is short, and they will find themselves on their own probably in about a month. This seemed like a close-knit family–the yearlings were staying very close to their mother. What will they think when she abandons them (so she can mate again)?

The same day, I read that an already-abandoned yearling in Great Smoky Mountains National Park bit a visitor who allowed the bear to approach him for a photograph. The visitor received a minor wound not requiring medical attention, a cool story, and probably some nice photographs. The 60-pound yearling received an early end to her life.

I’ve noticed over the years that yearlings–the teenagers of the bear world–behave rather similarly to teenagers of the human world: they think they’re invincible. I’ve noticed how they seem to have little fear of people and frequently approach people or allow people to approach them. Oddly, this is something they wouldn’t have tolerated while with their mother–and (if they make it past their yearling phase) is something they tolerate a lot less when they’re older.

So, the question is: how will these yearlings fare? It depends on us respecting these bears from a distance, lest they meet the fate of the Smokies yearling.

Sow and yearlings

Sow and yearlings in Yosemite Valley

(You can read the Great Smoky Mountains story at the website of the Asheville Citizen-Times.)

I worked my first night shift last Friday. We saw a few different bears that night, including a bear that knows how to break into cars and houses and a young bear who appears to be completely unafraid of people (but who doesn’t… yet… know how to break into anything; I suspect she’s been fed).

But the first bear I saw that evening was in an open area in the west Valley, away from any development. The bear was grazing on grass and never noticed us looking at him from 100 yards away. He had no tags, no collar; we’d never seen him before.

It was a beautiful bear, and a truly wild one. Come fall, this bear will still be beautiful. But will he still be wild?

Yes, indeed, had you walked into the Yosemite Valley post office on Saturday morning, you would have found bear prints on the floor, caused (apparently) by the bear finding a not-empty cup of hot chocolate.

There have been various other sightings in the last few weeks in Yosemite Valley… at Curry Village, around a few different housing areas, and by Lower Yosemite Fall (where I recently had my first sighting of the year).  The Tuolumne Meadows winter rangers have seen two sets of bear tracks already.

Thus it begins!

Imagine eating as much food as you could, then taking a nap. When you awoke, you’d realize weeks had gone by! What to do? Eat as much as you can and fall back to sleep! Repeat until it’s nice and warm outside. This is what many hibernating animals do, and they do it in order to conserve energy. (Many hibernating animals are small, so they lose body heat much more quickly than larger animals… I could explain, but it involves exponents…)

Bears aren’t typically considered small animals, yet the hibernate. Or do they? This seems to be an everlasting debate, but the current consensus (if there even is one) is that bears do hibernate–just differently from other hibernators. Black bears can maintain their body heat in winter if they choose, but they have a hard time finding enough food to stay alive in most places where they live. Hibernation is their solution to the food shortage. By hibernating, they can make it through the winter with just their fat.

When bears hibernate, their body temperature cools just a bit and their respiration and heart rate slow a little. They don’t eat or drink at all during hibernation (they even develop a fecal plug!) Since bears don’t cache food (like most other hibernators), they eat as much as possible before hibernation–a state called hyperphagia (literally, in Greek: over-eating). During hyperphagia, bears may eat 10,000 to 20,000 calories per day (compared to around 4,000 per day at other times).

So far this year, it seems like all the bears in Yosemite Valley are hibernating. There has been only one sighting this winter. This isn’t always true, and it’s not uncommon for a bear to be active the whole winter if enough food is available. Last winter, several bears remained active–perhaps because there was a bumper crop of live oak acorns that persisted even until spring.

I wonder sometimes… what would it be like to be able to hibernate?

Some of you reading my last post surely picked up on the part where I said that yelling aggressively at a bear will cause it to leave “almost always.”

I’ve only not been able to scare a bear away once. There have been a few other times when I’ve had trouble scaring a bear away, but ultimately succeeded.

One late afternoon in 2000, I (with others) responded to a report of a bear near Upper Pines Campground. The bear, a large male I was quite familiar with at that point, hung out for a while near (but outside) the campground. So, we just kept an eye on him for a while. Eventually, the bear wandered some more and vanished. (Bears are surprisingly good at this.)

So, we all split up and went to various nearby places to see if we could find the bear again. I went to Lower Pines Campground and found the bear in the campground as he walked up to a locker and tried to open it, but it was latched, so he couldn’t. He went to the next locker, which wasn’t completely latched (see Smart Bear Tricks, part 3), and he opened it up and started dragging food out. When I tried to scare him away, he didn’t budge. When I tried harder, he got up from his meal and started walking toward me with what’s often called the “cowboy swagger.” At that point, early in my bear career, I hadn’t ever heard of this behavior, so I was unsure of what to do, other than back up. (We were within feet of each other.) While I had been bluff charged by this bear in previous encounter–to very close–this actually seemed scarier! So, he continued to eat, and I stood there helplessly watching… and waiting for the wildlife crew to show up.

Do you remember the first time you ever saw a bear in the wild? Were you scared? (If you’ve never seen a bear in the wild, would you be scared if you did?)

I was quite scared the first time I ever saw a bear, near the trailhead parking in Yosemite Valley. I’ve spent most of the 18 years since then working with bears in Yosemite and have now seen bears hundreds of times. These days, it takes a lot for a bear to scare me. I’m that comfortable around black bears (in Yosemite, at least).

Bears are the same way. They are born afraid of people. Nearly all of them, even in Yosemite, seem to remain deathly afraid of us, even when they’re big, dominant males. But, if they regularly spend time around people, they slowly get more comfortable around us–just like I got comfortable with bears by working with them so much. This is how bears get into trouble. Once they’re comfortable around people, our abundant, high-calorie food is all that more tempting (and obtainable) to them.

And this is why it’s critically important to scare black bears when they approach people or are in developed areas. (This is true in the national parks of the Sierra Nevada–it isn’t true everywhere, so always heed local instructions.) Bears learn quickly when people are afraid of them, and even more quickly when they get food out of the encounter.

So, how do you scare a bear away? Yell as loudly as possible at it (we usually say “go away bear!” or “get out of here, bear!”) Obviously, it doesn’t really matter what you say, but if you’re yelling something like that at a bear, you’re more likely to mean it. And this is the trick. You have to mean it! You could make all the noise in the world, but if the bear doesn’t think you mean it, it’ll probably ignore you. You can see an example of yelling without meaning it not working very well in this video.


Video by Zack/UTubeLightBulb via Youtube.

It turns out, in my experience, that bears like this one are very good at reading human body language. (I also wonder if, with their superb sense of smell, they can smell fear… or lack thereof.) Confident people yelling at a bear always results in the bear leaving more quickly than when un-confident people are yelling. I’ve frequently shown up at the scene of a bear in a campsite because I could hear lots of people making lots of noise with no effect, but then I, with my lone voice, scared the bear away in a second.

So, to scare a bear away, you want to yell, in your loudest possible voice, “GO AWAY BEAR!” and keep repeating it until the bear leaves. Use your voice aggressively and be mad at the bear, and mean it. Forget the car alarms, pots and pans, clapping, whistles, or whatever else. These don’t work. Yell at the bear like you’re the boss and you’re demanding it to leave, and it will (almost always).

PS: In Yosemite, we tell people not to chase bears because doing so without training can be dangerous. However, walking toward or running just a few steps toward a bear (while already yelling at it) can be helpful if you’re careful and are sure the bear has an escape route.

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…

I’ve recently encountered two bits of good news about Yosemite’s bears and what they eat.

In an article published in the November Ursus (not available online, as far as I can tell), researchers published their results from studying 500 bear scats in 2001-2002. Yes, they actually picked up as many bear scats as they could find, then picked them apart to see what food items they contained. They did this to determine what bears were eating. Another scientist did the same research in the late 1970s, when the National Park Service was just beginning to reduce human food availability.

Compared to the 1970s, Yosemite Valley’s bears are now eating far less human food (and apparently replacing it with greens)!

Bear scat

Bear scat containing mostly grass.


Item 1970s 2000s
Human food 21% 6%
Fruit and acorns 53% 51%
Roots, grasses, etc.
17% 29%
Animal matter 2% 3%
Debris 7% 10%

Another study that hasn’t been published yet finds basically the same thing by looking carbon isotopes in the hairs of bears through the decades. According to that study, and if I’ve understood it correctly, it seems that bears in Yosemite Valley are eating as little human food as they did in the earliest years of the 20th century–before the open dumps.

So, everyone’s work to improve food storage has really paid off in a big way.

My previous post about acorns reminded me of a bear, Green 52, who provides a good example of how far bears will go to get acorns.

Green 52 was a black-colored bear (fairly rare in the Sierra) who appeared one spring and was often seen grazing in the meadows. He caused frequent and long-lasting bear jams, which allowed him to slowly get habituated to people (as he got comfortable as people ventured closer and closer to him). Despite becoming habituated, he didn’t seem to get much (if any) human food. One day, he passed through Curry Village, and followed his nose to a tent cabin (illegally) containing quite a bit of food.

He was never quite the same.

We started seeing him more and more in campgrounds and other developed areas.  He even broke into the Village Store (a grocery store) via an open window. (Later in summer, apple trees have lots of apples in Yosemite Valley, so it’s somewhat amusing that the first food he went for once inside the grocery store was… apples. He later found his way to the pastries.) What goes through a bear’s mind when it finds itself inside a grocery store?

Black bear up a snag, eating acorns

Green 52 picking acorns out of the snag. (NPS photo by Kate McCurdy)

Even the most food-conditioned bears seek out their natural foods, and Green 52 was no exception. With the arrival of fall, he tried to eat as many acorns as possible, although he may have been a bit more ingenious doing this than other bears. One day, the wildlife crew found Green 52 up a snag near their office. It turns out that acorn woodpeckers had converted the snag into a granary (as they do to many snags in Yosemite Valley), where they had stored hundreds of acorns. Green 52 had climbed the tree and was painstakingly removing the acorns from each hole the woodpeckers had pecked and filled with an acorn.

It just goes to show you that bears will leave no stone unturned as they search for food, particularly in the fall, when they’re hyperphagic (very hungry, consuming 10,000 to 20,000 calories per day).

As for Green 52, I don’t remember all the details, but we relocated him north of Yosemite Valley. After that, he left the park and began getting into trouble in areas outside the park near Highway 108. As a result California Fish & Game trapped and killed him.

« Previous PageNext Page »