1 00:00:02,040 --> 00:00:07,000 Speaker 1: Welcome to brain stuff from how stuff works. A brain 2 00:00:07,040 --> 00:00:10,719 Speaker 1: stuff is Christian zagger. Here. Despite how common North American 3 00:00:10,760 --> 00:00:14,440 Speaker 1: tree squirrels are in many cities, neighborhoods, and outdoor spaces, 4 00:00:14,560 --> 00:00:19,239 Speaker 1: a big misconception exists about these little critters. Tree squirrels 5 00:00:19,360 --> 00:00:24,239 Speaker 1: store their food tree fruit like acorns in their nests 6 00:00:24,360 --> 00:00:28,360 Speaker 1: or dens to snack on all winter. Here's the thing 7 00:00:28,760 --> 00:00:31,680 Speaker 1: they actually don't do that. First, it's important to know 8 00:00:31,760 --> 00:00:34,920 Speaker 1: that both the Eastern gray and Eastern fox squirrels dine 9 00:00:34,960 --> 00:00:40,760 Speaker 1: on a varying menu of seeds, nuts, acorns, tree buds, berries, leaves, 10 00:00:41,000 --> 00:00:43,720 Speaker 1: parts of pine cones, and other food some of us 11 00:00:44,000 --> 00:00:46,200 Speaker 1: well we don't like to think about, like bird eggs 12 00:00:46,200 --> 00:00:49,800 Speaker 1: and nestlings, and as well. You know they'll have the 13 00:00:49,800 --> 00:00:53,080 Speaker 1: occasional slice of found pizza. Some of that stuff they 14 00:00:53,120 --> 00:00:55,800 Speaker 1: eat right away, the rest they take to the nest 15 00:00:56,040 --> 00:00:59,960 Speaker 1: or den for later. But when winter approaches, squirrels are 16 00:01:00,040 --> 00:01:03,520 Speaker 1: faced with a challenge. They know instinctively that food sources 17 00:01:03,520 --> 00:01:06,000 Speaker 1: will soon be scarce, so they gather all the food 18 00:01:06,040 --> 00:01:10,920 Speaker 1: they'll need while also keeping themselves fed day today. That's 19 00:01:11,000 --> 00:01:14,120 Speaker 1: why they're so busy in the fall. When Mother nature 20 00:01:14,200 --> 00:01:17,360 Speaker 1: has made sure that all the acorns have fallen from 21 00:01:17,400 --> 00:01:21,920 Speaker 1: the trees. Second, Eastern gray and Eastern fox squirrels are 22 00:01:22,440 --> 00:01:25,440 Speaker 1: scatter hoarders, which means pretty much what it sounds like. 23 00:01:25,600 --> 00:01:28,720 Speaker 1: They hoard their food and then scatter it in locations 24 00:01:28,760 --> 00:01:32,760 Speaker 1: where they can easily access it. That's usually close to 25 00:01:32,800 --> 00:01:36,120 Speaker 1: the tree holding their nest or den, but they often 26 00:01:36,240 --> 00:01:40,399 Speaker 1: expand into areas of seven acres or two point eight 27 00:01:40,560 --> 00:01:45,040 Speaker 1: hectic ers, and rather than leaving their goods above ground 28 00:01:45,080 --> 00:01:48,400 Speaker 1: where other squirrels can steal them, they bury them, and 29 00:01:48,480 --> 00:01:52,000 Speaker 1: this is called cashing about an inch maybe two point 30 00:01:52,080 --> 00:01:55,920 Speaker 1: five centimeters under the soil, and squirrels are known to 31 00:01:56,160 --> 00:01:59,560 Speaker 1: crack open a nut before burying it so they can 32 00:01:59,640 --> 00:02:02,800 Speaker 1: keep it from germinating. When it comes time to eat, 33 00:02:03,080 --> 00:02:06,320 Speaker 1: they forage for the nuts they buried. While squirrels possess 34 00:02:06,400 --> 00:02:09,040 Speaker 1: a strong sense of smell, which allows them to sniff 35 00:02:09,080 --> 00:02:12,440 Speaker 1: out nuts from under a blanket of dirt, researchers have 36 00:02:12,600 --> 00:02:16,799 Speaker 1: long noticed evidence of strategic intelligence in the placement of 37 00:02:16,960 --> 00:02:20,679 Speaker 1: their food. For instance, one study in two thousand eight 38 00:02:20,680 --> 00:02:25,720 Speaker 1: reported that Eastern gray squirrels engage in what's called deceptive cashing. 39 00:02:26,040 --> 00:02:28,840 Speaker 1: They dig a hole pretend to throw the acorn in 40 00:02:29,360 --> 00:02:31,800 Speaker 1: while they hold it in their mouth. Then they cover 41 00:02:31,880 --> 00:02:35,040 Speaker 1: up the empty hole and run off to another secret 42 00:02:35,080 --> 00:02:38,600 Speaker 1: stash place. And they do this it was suggested to 43 00:02:38,840 --> 00:02:42,120 Speaker 1: fool other squirrels who might be watching them. But a 44 00:02:42,120 --> 00:02:45,600 Speaker 1: new study from professors in the Department of Psychology at 45 00:02:45,600 --> 00:02:49,520 Speaker 1: the University of California at Berkeley and published in the 46 00:02:49,560 --> 00:02:53,240 Speaker 1: September issue of the journal Royal Society of Open Science, 47 00:02:53,600 --> 00:02:58,640 Speaker 1: claims that tree squirrels use a pneumonic technique called spatial 48 00:02:59,080 --> 00:03:04,680 Speaker 1: chunking to sort out and bury their nuts scores by size, type, 49 00:03:04,720 --> 00:03:09,280 Speaker 1: and perhaps nutritional value and taste now when they're hungry later, 50 00:03:09,440 --> 00:03:13,560 Speaker 1: it's theorized they can remember where to find what they want. 51 00:03:13,840 --> 00:03:17,600 Speaker 1: In other words, the squirrels put specific nuts in similar 52 00:03:17,600 --> 00:03:21,359 Speaker 1: places to help them remember what nuts were where. I e. 53 00:03:21,880 --> 00:03:24,919 Speaker 1: Almonds were placed in one general area, hazel nuts in another, 54 00:03:25,000 --> 00:03:27,480 Speaker 1: and I guess pizza would go in a third area. 55 00:03:27,919 --> 00:03:32,200 Speaker 1: This neumonic strategy has also been seen in rats. The 56 00:03:32,280 --> 00:03:35,560 Speaker 1: finding researchers right in. The studies show that a scatter 57 00:03:35,680 --> 00:03:40,440 Speaker 1: hoarder could employ spatial chunking during cash distribution as a 58 00:03:40,520 --> 00:03:46,040 Speaker 1: cognitive strategy to decrease memory load and hence increase accuracy 59 00:03:46,160 --> 00:03:49,440 Speaker 1: of retrieval. Squirrels have got a lot to think about. 60 00:03:49,480 --> 00:03:52,920 Speaker 1: In other words, they need all the memory tricks they 61 00:03:52,960 --> 00:03:55,280 Speaker 1: can get, so the next time you see a squirrel 62 00:03:55,360 --> 00:03:57,920 Speaker 1: digging up a nut, know that she might have just 63 00:03:58,040 --> 00:04:07,160 Speaker 1: found the exact one she was hoping for. Today's episode 64 00:04:07,200 --> 00:04:10,320 Speaker 1: was written by Jamie Allen, produced by Tristan McNeil and 65 00:04:10,360 --> 00:04:13,240 Speaker 1: For more on this and other topics, please visit us 66 00:04:13,320 --> 00:04:26,360 Speaker 1: at how stuff works dot com.