December 2009

I saw an article like this one maybe a year ago and was intrigued by the concept that not thinking about a dilemma can lead to a better decision than obsessing over it. In fact, since I read that, I’ve let this process help me out with lots of little, unimportant decisions. It seems true: not thinking about a decision I have to make seems to work better than debating it constantly, whether the decision is big or little.


Why ‘Sleeping on It’ Helps

By John M. Grohol, PSYD,

posted: 26 October 2009 06:59 pm ET

We’re often told, “You should sleep on it” before you make an important decision. Why is that? How does “sleeping on it” help your decision-making process?

Conventional wisdom suggests that by “sleeping on it,” we clear our minds and relieve ourselves of the immediacy (and accompanying stress) of making a decision. Sleep also helps organize our memories, process the information of the day, and solve problems. Such wisdom also suggests that conscious deliberation helps decision making in general. But new research (Dijksterhuis et al., 2009) suggests something else might also be at work — our unconscious.

Previous research suggests that sometimes the more consciously we think about a decision, the worse the decision made. Sometimes what’s needed is a period of unconscious thought — equivalent to “sleeping on it” according to the researchers — in order to make better decisions.

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…

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.