WEBVTT 00:00:05.120 --> 00:00:07.980 [music] 00:00:31.590 --> 00:00:36.250 MALE: The Northern Range is the hub of wildlife in Yellowstone. 00:00:37.100 --> 00:00:41.340 So much of the wildlife in Yellowstone lives here. 00:00:42.720 --> 00:00:46.560 It's ten percent of the area of the park yet half the wolves live here. 00:00:48.100 --> 00:00:52.240 It's arguably the most carnivore rich area in North America 00:00:52.540 --> 00:00:54.240 and it's been studied a lot. 00:00:55.800 --> 00:01:00.199 WOMAN: The Northern Range has been referred to as the Serengeti of North America 00:01:00.200 --> 00:01:04.600 and that's because of the vast numbers of ungulate species mostly, and so 00:01:04.820 --> 00:01:10.000 when people look out they may, in one afternoon in the valley bottom of 00:01:10.009 --> 00:01:15.890 a Northern Range valley, they may see bison, elk, pronghorn, mule deer, wolves and bears 00:01:15.890 --> 00:01:19.210 and all of these species interacting with each other. 00:01:21.300 --> 00:01:26.280 MALE: Well, the Northern Range is the northern area of the park where 00:01:26.280 --> 00:01:31.240 the northern Yellowstone elk herd spends the winter. 00:01:31.900 --> 00:01:34.240 [elk bugles] 00:01:34.760 --> 00:01:39.420 So it's winter range for the biggest elk herd in the park, 00:01:39.660 --> 00:01:46.380 it's probably the densest year round wolf population at any location in North America. 00:01:46.480 --> 00:01:53.600 We roughly have 35 to 40 wolves year round in the park portion of the Northern Range, 00:01:53.600 --> 00:01:56.800 but we've been as dense as a hundred wolves 00:01:56.810 --> 00:02:01.880 just in the northern part of Yellowstone, and we have pretty high bear densities 00:02:01.880 --> 00:02:07.380 and cougar densities as well. So we have a great mix of carnivore species 00:02:07.440 --> 00:02:12.520 and we have high density. You know, 50 years ago that was not the case. 00:02:12.860 --> 00:02:15.900 [music] 00:02:16.250 --> 00:02:21.080 CASSIDY: We came into the Northern Range as Yellowstone was designated a park 00:02:21.080 --> 00:02:25.760 and changed a lot of things. So wolves, coyotes, mountain lions, bears to some degree 00:02:25.760 --> 00:02:29.280 were all being removed in vast numbers. 00:02:30.080 --> 00:02:35.140 SMITH: Wolves were eliminated by people directly in the early part of the 20th century. 00:02:35.150 --> 00:02:39.870 So what happens when you kill off the predators? Well, the prey increases to very high levels 00:02:39.880 --> 00:02:43.560 and starts to impact the environment and by doing that the elk herd shot up, 00:02:43.560 --> 00:02:46.400 and no one really knows how high they shot up, 00:02:46.560 --> 00:02:52.660 20 to 30 thousand was the estimated figure and they were degrading the environment. 00:02:55.440 --> 00:03:01.290 Our policy on helping restore nature is fairly clear: if humans did it we'll help 00:03:01.290 --> 00:03:04.290 the system get back on the right track. 00:03:04.940 --> 00:03:07.900 So what was missing was all these carnivores 00:03:07.900 --> 00:03:11.820 and so they were not performing their ecological function. 00:03:14.630 --> 00:03:18.830 Cougars came back to Yellowstone on their own through natural dispersal. 00:03:18.830 --> 00:03:23.510 We started seeing signs of that in the eighties and we reintroduced wolves in the mid nineties 00:03:23.520 --> 00:03:27.940 and now that wolves and cougars have been restored and bears have increased 00:03:28.100 --> 00:03:31.940 the new story is about what happened to all the elk, 00:03:32.140 --> 00:03:36.540 and what is happening to the willow and aspen now that the elk have declined 00:03:36.680 --> 00:03:38.500 and these carnivores are back. 00:03:40.980 --> 00:03:46.140 CASSIDY: Willow is relied on by a lot of animals and so it's kind of a positive feedback loop: 00:03:46.200 --> 00:03:50.280 the more willows there are, the more moose and beaver, 00:03:50.340 --> 00:03:55.160 and the healthier the ecosystem because of those animals being involved too. 00:03:56.420 --> 00:04:00.920 And so beavers are, of course, nature's engineers and they'll build lodges and dams 00:04:00.920 --> 00:04:05.140 that will help raise the water tables and raising the water table is 00:04:05.200 --> 00:04:08.060 one of the things that the willows rely on the most. 00:04:08.060 --> 00:04:11.540 They can't deal with cut banks and swiftly moving creeks. 00:04:11.540 --> 00:04:14.020 They have to have that slow moving water. 00:04:16.000 --> 00:04:19.440 SMITH: So this smaller elk herd is more natural, 00:04:19.609 --> 00:04:23.240 we're seeing a response of willow and aspen, which used to be suppressed. 00:04:23.240 --> 00:04:28.220 We've got wolves and cougars back, we've got more bears, so Yellowstone's system now 00:04:28.220 --> 00:04:31.220 is a National Park Service success story. 00:04:31.220 --> 00:04:33.220 [music] 00:04:33.320 --> 00:04:36.920 CASSIDY: I think the Northern Range is incredibly unique, 00:04:37.000 --> 00:04:41.900 not only for the Greater Yellowstone Ecosystem, but for the world. 00:04:42.960 --> 00:04:46.980 Protecting Yellowstone is important to just protect the species that live here, 00:04:46.980 --> 00:04:52.940 but also provide people a place to be able to see natural processes and use that throughout their life 00:04:52.940 --> 00:04:55.620 for making decisions on what they think is important. 00:04:56.060 --> 00:04:58.980 [elk bugles] 00:05:00.420 --> 00:05:08.000 SMITH: I think a huge value of the national parks is to instill awe of nature into people. 00:05:08.000 --> 00:05:13.880 Going out on landscape filled grizzly bears is not the same as, you know, going to the mall 00:05:13.940 --> 00:05:19.920 and seeing wolves bring down an elk or seeing two wolf pack's clash right in front of you 00:05:19.920 --> 00:05:22.320 are life-altering events. 00:05:22.320 --> 00:05:27.880 There's no question we are changing people's lives by having places like Yellowstone. 00:05:28.300 --> 00:05:32.660 And the Northern Range is probably the heart of the park 00:05:32.700 --> 00:05:37.380 and the park is the heart of the ecosystem, so it's all built upon each other, 00:05:37.420 --> 00:05:39.720 but ground zero is the Northern Range.