WEBVTT - City Birds Use Cigarette Butts as Bug Repellent 0:00:02.040 --> 0:00:07.040 Welcome to brain stuff from how stuff works, Hey, brain stuff, 0:00:07.080 --> 0:00:10.760 Lauren Bogelbaum. Here, the house sparrows and finches of Mexico 0:00:10.800 --> 0:00:13.880 City may be proud to be called bird brains, and 0:00:13.920 --> 0:00:16.119 why not. They figured out how to use one of 0:00:16.120 --> 0:00:19.239 the grossest things on Earth, cigarette butts, to repel two 0:00:19.320 --> 0:00:22.240 of the other grossest things on Earth, ticks and mites. 0:00:22.920 --> 0:00:26.160 MoMA birds find their nests under constant and pervasive threat 0:00:26.200 --> 0:00:30.800 from these blood sucking, feather feasting ectoparasites. Country birds have 0:00:30.880 --> 0:00:34.920 easy access to nature's bountiful nest making materials, including certain 0:00:35.000 --> 0:00:38.159 insect repelling herbs and plants. City dwelling birds, on the 0:00:38.200 --> 0:00:41.479 other hand, face a concrete and steel urban landscape and 0:00:41.560 --> 0:00:44.480 must curate their nests from a more anthropogenic or man 0:00:44.479 --> 0:00:49.240 made palette enter cigarette butts. A study published in twelve 0:00:49.280 --> 0:00:52.839 in the journal Biology Letters details the ongoing investigation of 0:00:52.880 --> 0:00:56.480 an urban population of breeding house finches and house sparrows 0:00:56.680 --> 0:00:59.760 at the National University of Mexico in Mexico City. The 0:01:00.000 --> 0:01:03.160 author's found that both species interweaved anywhere from a few 0:01:03.200 --> 0:01:06.200 to a few dozen smoked cigarette butts into their twiggy 0:01:06.440 --> 0:01:10.440 eclectic domiciles. In fact, the study concluded, the more butts, 0:01:10.600 --> 0:01:14.280 the healthier the nest. Nicotine is an insecticide generated by 0:01:14.280 --> 0:01:18.080 the tobacco plant to ward off invasive leaf eating arthropods 0:01:18.120 --> 0:01:21.360 like beetles. Some residual nicotine remains in the fibers of 0:01:21.440 --> 0:01:24.800 cigarette butts that motherbirds used to line and insulate their nests. 0:01:25.240 --> 0:01:28.160 It turns out that this nicotine tinged filter fluff has 0:01:28.319 --> 0:01:32.640 medicinal and pesticidal properties that repel tis, in particular, protecting 0:01:32.680 --> 0:01:36.319 MoMA's chicks from a potentially lethal fate. Overall, the study 0:01:36.360 --> 0:01:39.039 concludes that the more cigarette filter fiber there is in 0:01:39.040 --> 0:01:42.520 the nest, the fewer ticks and mites, revealing persuasive evidence 0:01:42.520 --> 0:01:45.520 that parasites don't like cigarette butts and that nests built 0:01:45.560 --> 0:01:50.480 with these butts attract fewer parasites. But there's no Avian 0:01:50.560 --> 0:01:54.600 surgeon general, so who decides whether this seemingly beneficial cigarette 0:01:54.640 --> 0:01:57.680 habit harms the birds or is a savvy and resourceful 0:01:57.720 --> 0:02:01.840 example of urban wildlife adaptation. Researchers confirmed that there is 0:02:02.000 --> 0:02:04.960 some genetic damage linked to the activity, but they believe 0:02:05.040 --> 0:02:08.720 that the positive life saving anti parasitic effects far outwaigh 0:02:08.760 --> 0:02:12.079 any long term negative consequences. So you've come a long 0:02:12.080 --> 0:02:14.560 way Bertie's, and you're helping clean up our cities while 0:02:14.600 --> 0:02:17.680 you're at it. Interestingly, there's another way that birds may 0:02:17.720 --> 0:02:21.240 help combat cigarette but litter. A Dutch startup Crowded Cities 0:02:21.560 --> 0:02:26.280 is developing the Crowbar and Autonomous training device to teach crows, 0:02:26.320 --> 0:02:28.680 some of the most competent scavengers in the world, to 0:02:28.760 --> 0:02:32.040 deliver found cigarette butts to a trash receptacle in exchange 0:02:32.120 --> 0:02:40.120 for food reward. Today's episode was written by Carrie Tato 0:02:40.280 --> 0:02:43.240 and produced by Tyler Clang, with kind engineering assistance by 0:02:43.320 --> 0:02:45.639 Ramsey yungt. For more on this and lots of other 0:02:45.680 --> 0:02:49.040 bird brained topics, by which we obviously mean clever and helpful, 0:02:49.360 --> 0:03:03.160 visit our home planet, how stuff Works dot com.