1 00:00:01,500 --> 00:00:06,633 ♪♪ 2 00:00:06,633 --> 00:00:10,400 GIAMATTI: If your neighbor is a woodpecker, you'll know it. 3 00:00:10,400 --> 00:00:11,933 [ Tapping ] 4 00:00:11,933 --> 00:00:15,600 ♪♪ 5 00:00:15,600 --> 00:00:18,400 Woodpeckers like to make noise. 6 00:00:18,400 --> 00:00:24,433 It's how they claim a territory and show off for mates. 7 00:00:24,433 --> 00:00:27,933 But with heads like hammers and bills like chisels, 8 00:00:27,933 --> 00:00:31,900 they do much more than sound off. 9 00:00:31,900 --> 00:00:34,966 Drumming is their song... 10 00:00:34,966 --> 00:00:38,666 drilling is how they find food... 11 00:00:38,666 --> 00:00:40,633 and highly skilled carpentry 12 00:00:40,633 --> 00:00:44,200 is how they craft their remarkable homes. 13 00:00:44,200 --> 00:00:47,466 ♪♪ 14 00:00:47,466 --> 00:00:50,933 These holes in trees, in many shapes and sizes, 15 00:00:50,933 --> 00:00:55,266 make woodpeckers important to everyone in the forest. 16 00:00:55,266 --> 00:00:57,933 [ Birds chirping ] 17 00:00:57,933 --> 00:01:04,333 They are architects, engineers, and consummate woodworkers, 18 00:01:04,333 --> 00:01:07,400 and this is their "hole" story. 19 00:01:10,300 --> 00:01:19,766 ♪♪ 20 00:01:19,766 --> 00:01:29,633 ♪♪ 21 00:01:47,933 --> 00:01:49,966 [ Birds chirping ] 22 00:02:00,233 --> 00:02:03,733 GIAMATTI: Among all the morning voices in a forest, 23 00:02:03,733 --> 00:02:06,833 there is one unmistakable sound. 24 00:02:06,833 --> 00:02:09,533 [ Tapping ] 25 00:02:11,166 --> 00:02:13,833 It's not made by a voice at all. 26 00:02:13,833 --> 00:02:16,533 [ Tapping continues ] 27 00:02:16,533 --> 00:02:20,633 It's a moment of percussion on a wooden instrument. 28 00:02:20,633 --> 00:02:26,466 ♪♪ 29 00:02:26,466 --> 00:02:29,800 It's the signature sound of a woodpecker. 30 00:02:29,800 --> 00:02:36,266 ♪♪ 31 00:02:36,266 --> 00:02:42,733 ♪♪ 32 00:02:42,733 --> 00:02:45,000 Woodpeckers don't sing. 33 00:02:45,000 --> 00:02:47,666 They drum. 34 00:02:47,666 --> 00:02:50,666 And they drum in every kind of forest, 35 00:02:50,666 --> 00:02:52,966 almost everywhere in the world. 36 00:02:52,966 --> 00:02:58,566 ♪♪ 37 00:02:58,566 --> 00:03:04,200 ♪♪ 38 00:03:04,200 --> 00:03:06,433 They're at home in trees throughout North 39 00:03:06,433 --> 00:03:08,966 and South America, 40 00:03:08,966 --> 00:03:12,933 across Europe, Asia, and Africa. 41 00:03:12,933 --> 00:03:16,600 the current count is 239 species in all. 42 00:03:16,600 --> 00:03:25,533 ♪♪ 43 00:03:29,400 --> 00:03:33,366 The Pileated woodpecker is a master of this world of wood 44 00:03:33,366 --> 00:03:36,466 and striking in every respect. 45 00:03:40,500 --> 00:03:43,766 He's one of the largest forest birds in North America. 46 00:03:47,533 --> 00:03:51,866 His name comes from the bright red crest across his pileum -- 47 00:03:51,866 --> 00:03:54,833 the top of his head from beak to nape. 48 00:03:58,166 --> 00:04:00,766 He drums to announce himself. 49 00:04:04,666 --> 00:04:09,633 Banging your head into a tree has always seemed reckless, 50 00:04:09,633 --> 00:04:12,033 but woodpeckers suffer no brain damage. 51 00:04:17,233 --> 00:04:20,033 His head and bill can act like a hammer 52 00:04:20,033 --> 00:04:22,400 because his brain is small enough to sustain 53 00:04:22,400 --> 00:04:25,666 repeated shocks without injury. 54 00:04:28,300 --> 00:04:31,700 But he does take safety precautions with his eyes. 55 00:04:34,166 --> 00:04:38,633 An extra eyelid closes at the moment of every impact. 56 00:04:42,400 --> 00:04:44,700 [ Distant tapping ] 57 00:04:51,933 --> 00:04:55,333 The Pileated slams hard into the decaying wood 58 00:04:55,333 --> 00:04:56,866 of a dead tree. 59 00:04:59,266 --> 00:05:02,866 He pounds with intent, 60 00:05:02,866 --> 00:05:06,533 then pauses to listen. 61 00:05:06,533 --> 00:05:08,700 He's hunting! 62 00:05:08,700 --> 00:05:14,333 ♪♪ 63 00:05:14,333 --> 00:05:17,700 His favorite quarry is deep in the rotten wood. 64 00:05:21,100 --> 00:05:23,200 He drills again... 65 00:05:23,200 --> 00:05:27,066 and listens again. 66 00:05:27,066 --> 00:05:32,100 ♪♪ 67 00:05:32,100 --> 00:05:35,933 Inside the tree, carpenter ants are frantic. 68 00:05:39,266 --> 00:05:42,033 It's a large colony that has made a home 69 00:05:42,033 --> 00:05:45,900 in what must have felt like a very safe place. 70 00:05:45,900 --> 00:05:51,700 ♪♪ 71 00:05:51,700 --> 00:05:56,466 They moved in when the tree was already dead or dying, 72 00:05:56,466 --> 00:05:59,400 its inner layers soft and decaying. 73 00:06:02,000 --> 00:06:04,600 They've chewed extensive galleries 74 00:06:04,600 --> 00:06:08,233 with passages and chambers where they are nurturing their young. 75 00:06:11,300 --> 00:06:15,000 Now, a monster is looming. 76 00:06:15,000 --> 00:06:19,733 A 19-inch killer dinosaur is at the door! 77 00:06:24,900 --> 00:06:29,700 He can hear the ants scurrying in panic. 78 00:06:29,700 --> 00:06:38,766 ♪♪ 79 00:06:38,766 --> 00:06:41,400 The Pileated redoubles his efforts, 80 00:06:41,400 --> 00:06:44,966 using his massive beak to rip into the wood. 81 00:06:44,966 --> 00:06:53,466 ♪♪ 82 00:06:53,466 --> 00:06:56,933 He carves out an enormous oblong opening. 83 00:06:56,933 --> 00:07:02,766 ♪♪ 84 00:07:02,766 --> 00:07:06,933 Inside, the ants are deploying their best defense. 85 00:07:06,933 --> 00:07:12,066 They've laid down formic acid to deter their predator's attack. 86 00:07:12,066 --> 00:07:15,200 But the woodpecker seems immune... 87 00:07:15,200 --> 00:07:17,266 licking the wood as he gets closer 88 00:07:17,266 --> 00:07:19,900 and closer to the colony... 89 00:07:19,900 --> 00:07:24,400 tasting their chemical deterrent with no ill effect. 90 00:07:24,400 --> 00:07:30,500 ♪♪ 91 00:07:30,500 --> 00:07:36,600 ♪♪ 92 00:07:36,600 --> 00:07:41,200 Inevitably, the determined Pileated prevails. 93 00:07:44,733 --> 00:07:46,833 The ant nest is breached, 94 00:07:46,833 --> 00:07:49,800 and the woodpecker begins to feast. 95 00:07:54,433 --> 00:07:57,933 Trees can't hide their secrets from him. 96 00:07:57,933 --> 00:08:03,066 It's as if he can see what's happening inside them. 97 00:08:03,066 --> 00:08:05,366 Perhaps that's no wonder. 98 00:08:05,366 --> 00:08:09,300 Trees have been his world for a very long time. 99 00:08:09,300 --> 00:08:17,500 ♪♪ 100 00:08:17,500 --> 00:08:20,566 We know that woodpeckers come from an ancient lineage 101 00:08:20,566 --> 00:08:25,566 that separated from other birds some 24 million years ago. 102 00:08:27,633 --> 00:08:30,833 And they are different in so many ways. 103 00:08:34,333 --> 00:08:36,466 [ Tapping ] 104 00:08:36,466 --> 00:08:40,366 Woodpeckers are all about trees. 105 00:08:40,366 --> 00:08:41,766 Even in the air. 106 00:08:41,766 --> 00:08:43,866 [ Squawking ] 107 00:08:47,933 --> 00:08:52,233 Their flight has an undulating pattern. 108 00:08:52,233 --> 00:08:56,933 A few wingbeats are followed by a tucked in glide -- 109 00:08:56,933 --> 00:09:01,266 a way of navigating through the branches. 110 00:09:01,266 --> 00:09:07,266 ♪♪ 111 00:09:07,266 --> 00:09:09,633 They are not long-distance travelers. 112 00:09:12,900 --> 00:09:16,766 They typically fly from tree to tree... 113 00:09:16,766 --> 00:09:20,100 and come in for vertical landings. 114 00:09:20,100 --> 00:09:29,033 ♪♪ 115 00:09:29,033 --> 00:09:32,066 With large, impressively clawed feet, 116 00:09:32,066 --> 00:09:34,866 they move across a tree trunk like rock climbers 117 00:09:34,866 --> 00:09:36,700 on walls of bark. 118 00:09:36,700 --> 00:09:44,166 ♪♪ 119 00:09:44,166 --> 00:09:47,666 They can even go exploring upside down. 120 00:09:47,666 --> 00:09:54,366 ♪♪ 121 00:09:54,366 --> 00:09:56,866 Their short legs are strong and work together 122 00:09:56,866 --> 00:09:59,366 with stiff specialized tail feathers 123 00:09:59,366 --> 00:10:03,366 to support their weight against the tree. 124 00:10:03,366 --> 00:10:04,766 This tripod provides 125 00:10:04,766 --> 00:10:07,800 the leverage they need to work the wood. 126 00:10:07,800 --> 00:10:15,533 ♪♪ 127 00:10:15,533 --> 00:10:17,866 What began as a way to find food... 128 00:10:17,866 --> 00:10:19,066 [ Tapping ] 129 00:10:19,066 --> 00:10:21,233 ...developed into a way to communicate. 130 00:10:23,566 --> 00:10:26,800 And so they "talk" to each other by drumming. 131 00:10:30,700 --> 00:10:34,866 Each species taps out its own rhythm, 132 00:10:34,866 --> 00:10:39,100 to stake out a territory... 133 00:10:39,100 --> 00:10:41,466 and call for a mate. 134 00:10:41,466 --> 00:10:45,966 ♪♪ 135 00:10:45,966 --> 00:10:48,766 [ Tapping ] 136 00:10:48,766 --> 00:10:56,633 ♪♪ 137 00:10:56,633 --> 00:11:01,300 When nesting season arrives, they carve deep into trees, 138 00:11:01,300 --> 00:11:04,100 hollowing out a family stronghold. 139 00:11:08,000 --> 00:11:13,266 These holes are the woodpeckers' universal trademark. 140 00:11:13,266 --> 00:11:17,366 No matter where they live, every woodpecker of every kind 141 00:11:17,366 --> 00:11:19,766 makes a hole for a home. 142 00:11:19,766 --> 00:11:23,300 [ Chirping ] 143 00:11:23,300 --> 00:11:26,500 It's a feature that unites the family, 144 00:11:26,500 --> 00:11:29,800 and it's what makes them such significant citizens 145 00:11:29,800 --> 00:11:31,633 of the forest. 146 00:11:31,633 --> 00:11:35,533 [ Chirping ] 147 00:11:47,500 --> 00:11:53,733 In the dark forests of Poland, in Stolowe National Park, 148 00:11:53,733 --> 00:11:57,666 wild and eerie calls inhabit the woods. 149 00:11:57,666 --> 00:12:00,266 [ Bird calls ] 150 00:12:02,600 --> 00:12:06,266 [ Tapping ] 151 00:12:06,266 --> 00:12:11,000 They belong to a pair of rarely filmed Black woodpeckers 152 00:12:11,000 --> 00:12:13,566 calling to each other through the trees. 153 00:12:13,566 --> 00:12:16,300 [ Calling ] 154 00:12:16,300 --> 00:12:18,766 They are large, imposing birds, 155 00:12:18,766 --> 00:12:22,200 jet black with a splash of red on their crowns. 156 00:12:22,200 --> 00:12:27,933 ♪♪ 157 00:12:27,933 --> 00:12:29,900 [ Woodpecker calls ] 158 00:12:32,166 --> 00:12:35,000 These two have made a home in a beech tree 159 00:12:35,000 --> 00:12:38,900 and are raising a family 80 feet up in the air. 160 00:12:42,933 --> 00:12:47,033 They dote on their three little chicks only eight days old. 161 00:12:49,166 --> 00:12:52,400 The nest hole is surprisingly deep. 162 00:12:52,400 --> 00:12:56,233 The adults have chiseled down 15 inches into the tree, 163 00:12:56,233 --> 00:12:59,866 painstakingly removing all the debris, 164 00:12:59,866 --> 00:13:01,733 except for a layer of wood chips 165 00:13:01,733 --> 00:13:03,700 that line the bottom of the hole. 166 00:13:07,233 --> 00:13:09,933 At first, the little woodies nap a lot, 167 00:13:09,933 --> 00:13:14,133 securely tucked away in their dark wooden womb. 168 00:13:14,133 --> 00:13:15,900 [ Chicks chirping ] 169 00:13:19,600 --> 00:13:23,233 But, soon, all the chicks are crying, all of the time... 170 00:13:31,533 --> 00:13:35,600 ...not the least interested in concealing their presence. 171 00:13:35,600 --> 00:13:40,033 The nest is so high, it's almost predator proof. 172 00:13:40,033 --> 00:13:44,266 ♪♪ 173 00:13:44,266 --> 00:13:47,433 Their father, in his full red cap... 174 00:13:47,433 --> 00:13:52,466 ♪♪ 175 00:13:52,466 --> 00:13:54,766 ...and their mother in her smaller one... 176 00:13:56,766 --> 00:13:59,266 ply back and forth with food... 177 00:13:59,266 --> 00:14:02,066 while the chicks grow and grow. 178 00:14:02,066 --> 00:14:08,366 ♪♪ 179 00:14:08,366 --> 00:14:12,833 With daylight approaching 17 hours at the height of June, 180 00:14:12,833 --> 00:14:15,300 there's no rest for the weary. 181 00:14:23,700 --> 00:14:25,766 Their forest is not the ancient world 182 00:14:25,766 --> 00:14:29,366 Black woodpeckers used to know. 183 00:14:29,366 --> 00:14:33,766 Most of these trees are young, less than a century old. 184 00:14:33,766 --> 00:14:37,233 But they're regaining old ground, 185 00:14:37,233 --> 00:14:41,266 and woodpeckers are an important part of their comeback story. 186 00:14:45,700 --> 00:14:50,133 The female is searching for her favorite meal -- carpenter ants. 187 00:14:54,133 --> 00:14:58,900 Her handiwork is easy to find in the forest. 188 00:14:58,900 --> 00:15:01,966 Her old nest holes from previous years, 189 00:15:01,966 --> 00:15:04,000 even her winter roosting holes, 190 00:15:04,000 --> 00:15:07,366 are bringing other creatures back into this forest. 191 00:15:10,233 --> 00:15:14,600 She's helping Eurasian Red squirrels... 192 00:15:14,600 --> 00:15:17,166 Great tits... 193 00:15:17,166 --> 00:15:20,400 and Boreal owls find homes here, too, 194 00:15:20,400 --> 00:15:22,600 where they can raise their own young. 195 00:15:22,600 --> 00:15:28,833 ♪♪ 196 00:15:28,833 --> 00:15:32,633 Her life's work is to make her world more diverse, 197 00:15:32,633 --> 00:15:37,600 more complex, more like it used to be. 198 00:15:37,600 --> 00:15:39,800 [ Chicks chirping ] 199 00:15:42,933 --> 00:15:44,433 Back in the nest, 200 00:15:44,433 --> 00:15:47,666 the chicks are beginning to look like real woodpeckers. 201 00:15:51,333 --> 00:15:54,966 From the red feathers sprouting on their own little crowns, 202 00:15:54,966 --> 00:15:58,666 it appears they are two females and one male. 203 00:15:58,666 --> 00:16:05,866 ♪♪ 204 00:16:05,866 --> 00:16:09,533 Their childhoods are brief. 205 00:16:09,533 --> 00:16:14,000 Soon, they will fly from this lofty hole... 206 00:16:14,000 --> 00:16:15,766 and three more Black woodpeckers 207 00:16:15,766 --> 00:16:19,800 will carry on their important work... 208 00:16:19,800 --> 00:16:23,666 making everything new old again. 209 00:16:23,666 --> 00:16:26,933 ♪♪ 210 00:16:34,500 --> 00:16:36,166 When the year turns 211 00:16:36,166 --> 00:16:38,933 and the New England woods are cold and snowy... 212 00:16:38,933 --> 00:16:41,866 [ Tapping ] 213 00:16:43,200 --> 00:16:45,933 ...the Pileated remains in his forest. 214 00:16:50,733 --> 00:16:53,966 He continues his search for ants and larvae, 215 00:16:53,966 --> 00:16:57,300 even when they've gone dormant and are no longer moving. 216 00:16:59,400 --> 00:17:02,766 A dead tree is an almost constant source of insects 217 00:17:02,766 --> 00:17:06,766 that he can mine all through the winter. 218 00:17:06,766 --> 00:17:11,366 ♪♪ 219 00:17:11,366 --> 00:17:13,400 In the very same forest, 220 00:17:13,400 --> 00:17:15,200 among the smallest of his cousins 221 00:17:15,200 --> 00:17:18,000 are also making their way through the season. 222 00:17:20,900 --> 00:17:23,300 The diminutive Downy woodpecker is named 223 00:17:23,300 --> 00:17:26,333 for the soft white feathers that keep them warm. 224 00:17:28,800 --> 00:17:32,666 Their black and white suits, with a dash of red for the male, 225 00:17:32,666 --> 00:17:37,266 are a miniature variation of the bold Pileated's, 226 00:17:37,266 --> 00:17:40,533 and offer them a way of blending into the trees. 227 00:17:40,533 --> 00:17:49,600 ♪♪ 228 00:17:49,600 --> 00:17:51,000 Downies search for insects 229 00:17:51,000 --> 00:17:53,500 that winter just beneath the bark. 230 00:17:57,600 --> 00:18:01,733 They often join small mixed bands of chickadees... 231 00:18:01,733 --> 00:18:04,100 white-breasted nuthatches... 232 00:18:04,100 --> 00:18:05,800 and tufted titmice. 233 00:18:05,800 --> 00:18:11,866 ♪♪ 234 00:18:11,866 --> 00:18:14,766 Several little birds may even roost together overnight 235 00:18:14,766 --> 00:18:17,066 if the weather is severe. 236 00:18:21,966 --> 00:18:26,833 ♪♪ 237 00:18:26,833 --> 00:18:29,633 But as winter thaws and spring arrives, 238 00:18:29,633 --> 00:18:34,500 the camaraderie turns to competition. 239 00:18:34,500 --> 00:18:37,500 They all want nests in tree cavities, 240 00:18:37,500 --> 00:18:40,700 and a woodpecker hole would do nicely. 241 00:18:43,766 --> 00:18:47,100 The little Downies are highly skilled carpenters 242 00:18:47,100 --> 00:18:50,866 and build a new nest every year. 243 00:18:50,866 --> 00:18:55,133 No small bird needing a home can resist a look inside. 244 00:18:57,466 --> 00:19:01,100 A chickadee can excavate its own nest in rotten wood, 245 00:19:01,100 --> 00:19:05,400 but a finished Downy nest would be so much easier. 246 00:19:08,133 --> 00:19:11,566 A white-breasted nuthatch wants a simple renovation, 247 00:19:11,566 --> 00:19:14,366 something it doesn't have to build from scratch. 248 00:19:17,433 --> 00:19:20,333 A little titmouse can't drill into wood at all. 249 00:19:20,333 --> 00:19:23,800 It needs an empty nest hole that's move-in ready. 250 00:19:23,800 --> 00:19:26,200 [ Chirping ] 251 00:19:27,466 --> 00:19:32,766 A lucky house wren has already laid claim to an empty hole 252 00:19:32,766 --> 00:19:35,533 and is bringing in her own nesting materials. 253 00:19:35,533 --> 00:19:41,266 ♪♪ 254 00:19:41,266 --> 00:19:46,200 And a family of tree swallows has commandeered another. 255 00:19:46,200 --> 00:19:49,966 The female has lined the hole with feathers and pine boughs. 256 00:19:49,966 --> 00:19:56,500 ♪♪ 257 00:19:56,500 --> 00:20:00,033 All these little birds know a woodpecker hole is 258 00:20:00,033 --> 00:20:04,233 the safest place in the forest to raise their chicks. 259 00:20:04,233 --> 00:20:06,766 [ Chirping ] 260 00:20:17,300 --> 00:20:20,733 As spring reaches north into the woods of Maine, 261 00:20:20,733 --> 00:20:24,833 a Ruby-throated hummingbird zings into the scene 262 00:20:24,833 --> 00:20:27,133 with a flash of green and red. 263 00:20:30,766 --> 00:20:34,333 He's come all the way from the tropics of Central America, 264 00:20:34,333 --> 00:20:37,500 nectaring on flowers as they bloom along his route. 265 00:20:39,766 --> 00:20:42,533 It's early May, and here in the north woods, 266 00:20:42,533 --> 00:20:45,933 flowers are still few and far between. 267 00:20:45,933 --> 00:20:51,066 He's pushing the limits of his ability to refuel. 268 00:20:51,066 --> 00:20:54,700 But he's got a brilliant backup plan. 269 00:20:54,700 --> 00:20:58,300 [ Tapping ] 270 00:20:58,300 --> 00:21:00,766 He's timed his migration to meet the return 271 00:21:00,766 --> 00:21:02,900 of a particular woodpecker -- 272 00:21:05,933 --> 00:21:08,233 the Yellow-bellied sapsucker. 273 00:21:11,400 --> 00:21:15,433 Sapsuckers are one of the few woodpeckers to migrate, 274 00:21:15,433 --> 00:21:20,400 coming back to the north just as the trees are waking up. 275 00:21:20,400 --> 00:21:24,500 They return to the same trees year after year. 276 00:21:24,500 --> 00:21:28,333 Birches are among their favorites. 277 00:21:28,333 --> 00:21:31,233 They tap into different streams of the tree's plumbing 278 00:21:31,233 --> 00:21:33,966 according to the type of sap they seek. 279 00:21:36,333 --> 00:21:39,300 The first holes in early spring intercept the sap 280 00:21:39,300 --> 00:21:42,166 coming up from the roots into the wood. 281 00:21:44,366 --> 00:21:48,033 These holes are small, round, and deep. 282 00:21:50,233 --> 00:21:55,533 Immediately, sap wells up in the wounds and spills over. 283 00:21:55,533 --> 00:21:57,800 This is called birch water. 284 00:21:57,800 --> 00:22:03,500 It's thin but full of minerals and hormones. 285 00:22:03,500 --> 00:22:07,766 The tree works to stem the flow and seal the wound. 286 00:22:07,766 --> 00:22:10,800 So the birds tap to the left 287 00:22:10,800 --> 00:22:12,933 and tap to the right, 288 00:22:12,933 --> 00:22:15,033 moving around the trunk. 289 00:22:18,266 --> 00:22:21,100 As spring unfolds, sapsuckers switch 290 00:22:21,100 --> 00:22:23,533 to a living layer of inner bark 291 00:22:23,533 --> 00:22:25,333 that sends all the nutrients made 292 00:22:25,333 --> 00:22:28,500 by the leaves down to the tree's roots. 293 00:22:28,500 --> 00:22:33,466 ♪♪ 294 00:22:33,466 --> 00:22:36,800 This sap is loaded with sucrose, 295 00:22:36,800 --> 00:22:41,133 and sapsuckers can't resist the sugary syrup. 296 00:22:44,100 --> 00:22:47,266 These shallow holes are large and square 297 00:22:47,266 --> 00:22:51,866 and contribute to a conspicuous pattern that moves up the tree. 298 00:22:51,866 --> 00:22:57,100 ♪♪ 299 00:22:57,100 --> 00:23:02,366 ♪♪ 300 00:23:02,366 --> 00:23:05,933 A well-worked sapsucker tree stands out like a beacon 301 00:23:05,933 --> 00:23:09,666 to the little Ruby-throated hummingbird. 302 00:23:09,666 --> 00:23:12,733 He plans to claim it as his territory, 303 00:23:12,733 --> 00:23:16,800 just in time to impress an arriving female. 304 00:23:16,800 --> 00:23:22,633 She's so eager for birch syrup, she can already taste it. 305 00:23:22,633 --> 00:23:23,800 But... 306 00:23:23,800 --> 00:23:26,500 she's going to have to wait her turn. 307 00:23:26,500 --> 00:23:35,133 ♪♪ 308 00:23:35,133 --> 00:23:37,666 Hummers live so close to the edge, 309 00:23:37,666 --> 00:23:41,733 they fiercely defend every source of food they have. 310 00:23:41,733 --> 00:23:44,533 Even when it's an entire tree! 311 00:23:44,533 --> 00:23:54,266 ♪♪ 312 00:23:54,266 --> 00:24:04,100 ♪♪ 313 00:24:04,100 --> 00:24:06,666 Even the little male, who was here first, 314 00:24:06,666 --> 00:24:08,333 is given a hard time. 315 00:24:08,333 --> 00:24:15,433 ♪♪ 316 00:24:15,433 --> 00:24:19,500 Insects, too, love the tree's sweet, sticky flow. 317 00:24:19,500 --> 00:24:23,633 But for them, it's a honey trap. 318 00:24:23,633 --> 00:24:26,300 Ingenious sapsuckers don't need to drill into wood 319 00:24:26,300 --> 00:24:28,266 for beetles and grubs. 320 00:24:28,266 --> 00:24:30,433 Sap does the catching for them. 321 00:24:30,433 --> 00:24:37,366 ♪♪ 322 00:24:37,366 --> 00:24:40,100 And even bees taste better... 323 00:24:40,100 --> 00:24:42,666 dipped in sugar. 324 00:24:46,166 --> 00:24:48,500 It may take years, but inevitably, 325 00:24:48,500 --> 00:24:52,700 the sapsuckers' holes gird the birch completely. 326 00:24:52,700 --> 00:24:56,133 Nutrients from the leaves can no longer reach the roots, 327 00:24:56,133 --> 00:25:00,366 and the tree finally dies. 328 00:25:00,366 --> 00:25:03,833 But death is not the end of a tree's story. 329 00:25:06,700 --> 00:25:12,133 Now it becomes food and shelter for a host of new creatures, 330 00:25:12,133 --> 00:25:14,900 chief among them the horned passalus, 331 00:25:14,900 --> 00:25:18,933 also known as the patent-leather beetle. 332 00:25:18,933 --> 00:25:23,833 ♪♪ 333 00:25:23,833 --> 00:25:26,500 This large black beetle finds the perfect home 334 00:25:26,500 --> 00:25:29,100 inside dead deciduous trees, 335 00:25:29,100 --> 00:25:32,900 with protection from wild swings in the weather... 336 00:25:32,900 --> 00:25:35,633 and with all the wood it can eat. 337 00:25:39,700 --> 00:25:42,133 Its larvae will develop here, too, 338 00:25:42,133 --> 00:25:44,566 gradually gaining a taste for wood. 339 00:25:48,400 --> 00:25:51,533 The beetles need dead trees to survive... 340 00:25:51,533 --> 00:25:53,533 and beetles help keep the forest system 341 00:25:53,533 --> 00:25:57,033 humming by nourishing so many birds and mammals. 342 00:26:01,433 --> 00:26:05,033 But the forest has many partners, 343 00:26:05,033 --> 00:26:09,966 and the greatest may be these remarkable beings. 344 00:26:09,966 --> 00:26:12,700 Fungi. 345 00:26:12,700 --> 00:26:20,300 ♪♪ 346 00:26:20,300 --> 00:26:27,866 ♪♪ 347 00:26:27,866 --> 00:26:33,266 Fungi bear "fruit" that carry their seed-like spores. 348 00:26:33,266 --> 00:26:36,333 We know them as mushrooms. 349 00:26:36,333 --> 00:26:44,733 ♪♪ 350 00:26:44,733 --> 00:26:47,333 Neither plants nor animals, 351 00:26:47,333 --> 00:26:51,000 fungi recycle all the components of the forest, 352 00:26:51,000 --> 00:26:55,033 spreading filaments underground in an organic internet. 353 00:26:55,033 --> 00:27:02,966 ♪♪ 354 00:27:02,966 --> 00:27:04,666 They break down fallen wood 355 00:27:04,666 --> 00:27:07,633 and send its nutrients far and wide... 356 00:27:10,000 --> 00:27:13,366 ...to be reincarnated into living trees. 357 00:27:17,733 --> 00:27:20,000 But while they're still standing, 358 00:27:20,000 --> 00:27:24,400 dead trees are essential architecture just as they are. 359 00:27:24,400 --> 00:27:25,900 [ Tapping ] 360 00:27:25,900 --> 00:27:33,200 ♪♪ 361 00:27:33,200 --> 00:27:35,900 Year after year, a small Hairy woodpecker 362 00:27:35,900 --> 00:27:38,566 makes nest holes in a flooded stand 363 00:27:38,566 --> 00:27:40,533 at the edge of a beaver pond. 364 00:27:40,533 --> 00:27:45,833 ♪♪ 365 00:27:45,833 --> 00:27:47,733 A dead tree with last year's hole 366 00:27:47,733 --> 00:27:50,433 is exactly the home Eastern bluebirds 367 00:27:50,433 --> 00:27:53,066 need to raise their own family. 368 00:27:53,066 --> 00:28:00,600 ♪♪ 369 00:28:00,600 --> 00:28:08,066 ♪♪ 370 00:28:08,066 --> 00:28:12,000 As they feed their chicks, the bluebirds have no idea 371 00:28:12,000 --> 00:28:15,666 how deeply connected everything in their forest is. 372 00:28:19,933 --> 00:28:24,466 All the bluebirds know is that the nest is precious... 373 00:28:24,466 --> 00:28:28,200 and they fiercely defend it... 374 00:28:28,200 --> 00:28:31,000 even from the little woodpecker who made it. 375 00:28:31,000 --> 00:28:37,966 ♪♪ 376 00:28:37,966 --> 00:28:44,900 ♪♪ 377 00:28:44,900 --> 00:28:46,733 The value of trees to woodpeckers 378 00:28:46,733 --> 00:28:49,333 rises to a dramatic crescendo 379 00:28:49,333 --> 00:28:52,266 in central California's Carmel Valley. 380 00:28:56,200 --> 00:28:59,233 It's a story that unfolds across a sweeping savanna 381 00:28:59,233 --> 00:29:02,100 of oaks and golden grasses. 382 00:29:05,733 --> 00:29:08,400 These gnarled old oaks have stood their ground 383 00:29:08,400 --> 00:29:11,200 for some 500 years. 384 00:29:15,300 --> 00:29:20,533 Their wide-reaching branches are festooned with lace lichen, 385 00:29:20,533 --> 00:29:23,633 and their bark is so thick and corrugated, 386 00:29:23,633 --> 00:29:27,566 they have weathered almost every challenge for centuries. 387 00:29:32,033 --> 00:29:35,433 But a closer look reveals something astonishing. 388 00:29:35,433 --> 00:29:41,233 ♪♪ 389 00:29:41,233 --> 00:29:45,600 Acorns, by the tens of thousands, 390 00:29:45,600 --> 00:29:48,800 are tattooed into every nook and cranny. 391 00:29:48,800 --> 00:29:58,133 ♪♪ 392 00:29:58,133 --> 00:30:01,200 Acorns don't grow this way. 393 00:30:01,200 --> 00:30:06,066 Someone has hammered each one into the bark. 394 00:30:06,066 --> 00:30:10,333 [ Squawking ] 395 00:30:10,333 --> 00:30:13,666 That someone is actually a band of little round-eyed, 396 00:30:13,666 --> 00:30:16,833 clown-faced, Acorn woodpeckers. 397 00:30:16,833 --> 00:30:25,566 ♪♪ 398 00:30:25,566 --> 00:30:29,566 They live in highly structured families of a dozen or so, 399 00:30:29,566 --> 00:30:33,000 each family claiming some 15 acres of oaks 400 00:30:33,000 --> 00:30:34,600 and open country. 401 00:30:38,366 --> 00:30:41,166 The trees are their prized possessions. 402 00:30:43,633 --> 00:30:48,233 Because every autumn, they produce a windfall. 403 00:30:48,233 --> 00:30:56,033 ♪♪ 404 00:30:56,033 --> 00:31:00,566 Thousands upon thousands of nutritious acorns. 405 00:31:00,566 --> 00:31:08,300 ♪♪ 406 00:31:12,433 --> 00:31:15,533 The acorns are woodpecker gold -- 407 00:31:15,533 --> 00:31:20,266 high in vitamins, minerals, fats, and protein. 408 00:31:20,266 --> 00:31:23,866 Collecting them is the woodpeckers' obsession. 409 00:31:23,866 --> 00:31:32,866 ♪♪ 410 00:31:32,866 --> 00:31:36,166 The acorns are ferried back up to the tree 411 00:31:36,166 --> 00:31:40,266 and packed into small holes pecked out for the purpose. 412 00:31:40,266 --> 00:31:45,833 ♪♪ 413 00:31:45,833 --> 00:31:50,233 This turns the acorns into treasure -- 414 00:31:50,233 --> 00:31:53,600 a seasonal abundance that can be made to last. 415 00:31:56,800 --> 00:32:01,166 When other foods are scarce, acorns will be here - 416 00:32:01,166 --> 00:32:04,566 safe in their shells and ready to eat. 417 00:32:12,566 --> 00:32:15,700 This is prosperity for the family, 418 00:32:15,700 --> 00:32:17,966 a true measure of wealth. 419 00:32:21,566 --> 00:32:25,600 But wealth, it turns out, is a whole lot of work. 420 00:32:25,600 --> 00:32:33,833 ♪♪ 421 00:32:33,833 --> 00:32:37,533 Now they constantly test and turn the acorns 422 00:32:37,533 --> 00:32:39,533 as they dry and shrink, 423 00:32:39,533 --> 00:32:43,366 to make sure each one is still snug in its hole. 424 00:32:43,366 --> 00:32:49,000 ♪♪ 425 00:32:49,000 --> 00:32:54,666 ♪♪ 426 00:32:54,666 --> 00:32:56,800 If the hole seems too big... 427 00:32:59,100 --> 00:33:02,500 ...they look for a better fit, 428 00:33:02,500 --> 00:33:05,333 tapping the acorn back in tight. 429 00:33:09,766 --> 00:33:12,600 It's a process fraught with difficult decisions. 430 00:33:12,600 --> 00:33:22,200 ♪♪ 431 00:33:22,200 --> 00:33:25,366 And an acorn dropped 432 00:33:25,366 --> 00:33:27,566 could be lost forever. 433 00:33:35,466 --> 00:33:39,733 Every member of the family serves on acorn security duty. 434 00:33:41,700 --> 00:33:45,166 ♪♪ 435 00:33:45,166 --> 00:33:49,133 A ground squirrel boldly climbs the oak 436 00:33:49,133 --> 00:33:53,400 only to find the entire tree is woodpecker property. 437 00:33:53,400 --> 00:33:55,066 [ Woodpeckers squawking ] 438 00:33:55,066 --> 00:34:04,166 ♪♪ 439 00:34:04,166 --> 00:34:07,366 Any outsider, whether furry or feathered, 440 00:34:07,366 --> 00:34:09,333 is swiftly dispatched. 441 00:34:11,433 --> 00:34:14,866 What worries the family most are raiding parties 442 00:34:14,866 --> 00:34:18,266 of competing Acorn woodpeckers. 443 00:34:21,000 --> 00:34:22,766 All across the valley, 444 00:34:22,766 --> 00:34:25,866 groups keep an eye on each other's holdings, 445 00:34:25,866 --> 00:34:29,566 waiting for an opening to take them over. 446 00:34:29,566 --> 00:34:37,600 ♪♪ 447 00:34:37,600 --> 00:34:40,933 Woodpecker spies are everywhere, 448 00:34:40,933 --> 00:34:43,200 and though they all look alike to us, 449 00:34:43,200 --> 00:34:46,966 the home team always knows who doesn't belong. 450 00:34:46,966 --> 00:34:49,166 [ Squawking ] 451 00:34:49,166 --> 00:34:55,133 ♪♪ 452 00:34:55,133 --> 00:35:01,166 ♪♪ 453 00:35:03,200 --> 00:35:05,500 While Acorn woodies remain tree-bound 454 00:35:05,500 --> 00:35:07,866 and devoted to their oaks, 455 00:35:07,866 --> 00:35:11,700 other woodpeckers have found success beyond the woods 456 00:35:11,700 --> 00:35:14,166 in open country. 457 00:35:14,166 --> 00:35:16,666 [ Squawking ] 458 00:35:19,000 --> 00:35:22,500 Across the American West, there lives a remarkable bird 459 00:35:22,500 --> 00:35:25,600 who's expanding woodpecker horizons. 460 00:35:28,500 --> 00:35:32,266 She barely looks like a woodpecker at all. 461 00:35:32,266 --> 00:35:36,366 Her feather palette is unlike any other in the family. 462 00:35:36,366 --> 00:35:40,800 Her face is deep red, her belly bright pink. 463 00:35:40,800 --> 00:35:45,800 And she sports an interesting collar of silvery-gray. 464 00:35:45,800 --> 00:35:49,766 This is a Lewis's woodpecker, named for the explorer 465 00:35:49,766 --> 00:35:54,533 Meriwether Lewis of Lewis and Clark fame. 466 00:35:54,533 --> 00:35:57,633 Her nest, at least, is traditional woodpecker, 467 00:35:57,633 --> 00:36:00,666 a deep hole chiseled out of a large cottonwood. 468 00:36:04,766 --> 00:36:08,400 But from here, she flies out to an open perch 469 00:36:08,400 --> 00:36:12,033 to scan the landscape for something to eat. 470 00:36:12,033 --> 00:36:14,933 In nesting season, 471 00:36:14,933 --> 00:36:18,700 the grasslands are rich in flowers... 472 00:36:18,700 --> 00:36:21,766 and in the insects that come to pollinate them. 473 00:36:24,200 --> 00:36:27,633 As the pollinators rise from their flowers, 474 00:36:27,633 --> 00:36:30,333 the Lewis's launches into the air. 475 00:36:32,933 --> 00:36:35,766 Instead of a woodpecker, 476 00:36:35,766 --> 00:36:38,900 she becomes a flycatcher, 477 00:36:38,900 --> 00:36:41,266 snapping up her prey on the wing. 478 00:36:41,266 --> 00:36:47,133 ♪♪ 479 00:36:47,133 --> 00:36:49,100 It's a technique called "hawking." 480 00:36:51,766 --> 00:36:56,133 In real time, it's hard to see if she's successful. 481 00:36:56,133 --> 00:37:00,300 But slowed down, it's impressive how adept she is. 482 00:37:00,300 --> 00:37:08,400 ♪♪ 483 00:37:08,400 --> 00:37:16,533 ♪♪ 484 00:37:16,533 --> 00:37:19,333 She returns to the nest trip after trip... 485 00:37:22,233 --> 00:37:25,766 ...with beakfuls of nutritious bugs for her chicks. 486 00:37:25,766 --> 00:37:31,233 ♪♪ 487 00:37:31,233 --> 00:37:36,700 ♪♪ 488 00:37:36,700 --> 00:37:40,133 And tops them off with gooseberries 489 00:37:40,133 --> 00:37:42,600 for dessert! 490 00:37:46,466 --> 00:37:53,000 ♪♪ 491 00:37:53,000 --> 00:37:56,866 And then, there are woodpeckers so unorthodox, 492 00:37:56,866 --> 00:38:00,166 they've abandoned trees altogether. 493 00:38:03,966 --> 00:38:09,366 Just outside of Tucson, Arizona, in the Sonoran Desert, 494 00:38:09,366 --> 00:38:11,266 the Gila woodpecker, 495 00:38:11,266 --> 00:38:15,400 with its beautifully patterned back and wings, 496 00:38:15,400 --> 00:38:19,400 is tucked into the only tree-like structure around -- 497 00:38:19,400 --> 00:38:23,266 a giant saguaro cactus. 498 00:38:23,266 --> 00:38:29,533 Mature saguaros like these could be 200 years old. 499 00:38:29,533 --> 00:38:35,033 The woodpecker holes themselves might date back 50 years. 500 00:38:35,033 --> 00:38:37,200 Many generations of Gila woodies come 501 00:38:37,200 --> 00:38:40,866 and go in the life of a grand desert sentinel. 502 00:38:40,866 --> 00:38:46,433 ♪♪ 503 00:38:46,433 --> 00:38:50,933 Nesting in a cactus takes planning in advance. 504 00:38:50,933 --> 00:38:54,733 After carving out the nest cavity in between the spines, 505 00:38:54,733 --> 00:38:57,733 the Gila must wait several months for the inner pulp 506 00:38:57,733 --> 00:39:01,200 to dry into a tough, leathery casing. 507 00:39:04,566 --> 00:39:06,266 With the nest ready to go, 508 00:39:06,266 --> 00:39:09,233 the male brings an impressive gift to the female, 509 00:39:09,233 --> 00:39:11,233 who is now sitting on eggs. 510 00:39:13,500 --> 00:39:16,300 And she delicately consumes it, 511 00:39:16,300 --> 00:39:20,233 one spidery leg at a time. 512 00:39:20,233 --> 00:39:27,366 ♪♪ 513 00:39:27,366 --> 00:39:29,366 Once chicks are in the nest, 514 00:39:29,366 --> 00:39:32,966 both parents fly out on foraging sorties... 515 00:39:36,100 --> 00:39:38,333 ...with the typical flap-flap-glide 516 00:39:38,333 --> 00:39:41,033 that works so well in forests. 517 00:39:41,033 --> 00:39:48,200 ♪♪ 518 00:39:48,200 --> 00:39:55,366 ♪♪ 519 00:39:55,366 --> 00:40:00,066 Though cacti are not trees, and the Sonoran is not a forest, 520 00:40:00,066 --> 00:40:04,500 the Gilas have found a woodpecker way to thrive here. 521 00:40:11,000 --> 00:40:13,733 Yet thousands of miles to the south, 522 00:40:13,733 --> 00:40:15,300 there's a woodpecker that has left 523 00:40:15,300 --> 00:40:19,100 even the semblance of trees far behind. 524 00:40:20,933 --> 00:40:25,066 It lives where no woodpecker should be at all -- 525 00:40:25,066 --> 00:40:26,800 in open Alpine meadows 526 00:40:26,800 --> 00:40:30,500 8,000 feet up in the Andes of Argentina. 527 00:40:33,333 --> 00:40:36,366 It carves holes here, not in wood, 528 00:40:36,366 --> 00:40:41,266 but in clay cliffs and the banks that line high country streams. 529 00:40:46,000 --> 00:40:49,400 [ Chirping ] 530 00:40:49,400 --> 00:40:52,033 This is the Andean flicker. 531 00:40:55,033 --> 00:40:57,833 He's called a "flicker" because his wings are tinged 532 00:40:57,833 --> 00:41:01,800 with gold and flash and flicker in the sunlight 533 00:41:01,800 --> 00:41:03,733 as he takes to the sky. 534 00:41:03,733 --> 00:41:10,966 ♪♪ 535 00:41:10,966 --> 00:41:13,666 Out in the grasslands, flickers make a living 536 00:41:13,666 --> 00:41:16,333 by using their long woodpecker beaks 537 00:41:16,333 --> 00:41:19,700 to probe for worms and insects in the soil. 538 00:41:22,866 --> 00:41:25,033 He's very committed to his mate. 539 00:41:27,233 --> 00:41:30,133 They like to forage close together, 540 00:41:30,133 --> 00:41:32,800 hitching across the open terrain like woodpeckers 541 00:41:32,800 --> 00:41:36,033 going up a tree. 542 00:41:36,033 --> 00:41:37,966 [ Calling ] 543 00:41:43,666 --> 00:41:47,233 They call back and forth to stay in constant contact. 544 00:41:47,233 --> 00:41:49,833 [ Calling continues ] 545 00:41:58,933 --> 00:42:02,000 After a moment, the male checks back in. 546 00:42:02,000 --> 00:42:05,333 [ Calling ] 547 00:42:05,333 --> 00:42:07,266 This time... 548 00:42:07,266 --> 00:42:09,266 there's no reply. 549 00:42:09,266 --> 00:42:19,100 ♪♪ 550 00:42:19,100 --> 00:42:28,933 ♪♪ 551 00:42:28,933 --> 00:42:31,500 He seeks higher ground to call again. 552 00:42:31,500 --> 00:42:33,233 [ Calling ] 553 00:42:35,700 --> 00:42:40,133 With no wood to work with, Andean flickers seldom drum. 554 00:42:40,133 --> 00:42:42,633 Calling is all he can do. 555 00:42:42,633 --> 00:42:44,733 [ Calling ] 556 00:42:44,733 --> 00:42:51,833 ♪♪ 557 00:42:51,833 --> 00:42:53,833 With the anxious moment over, 558 00:42:53,833 --> 00:42:57,033 the reunited pair share a brief display... 559 00:42:57,033 --> 00:42:59,733 [ Chirping ] 560 00:43:03,533 --> 00:43:05,933 ...and settle down to forage again. 561 00:43:05,933 --> 00:43:10,800 ♪♪ 562 00:43:10,800 --> 00:43:14,266 Adapting to life in the open 563 00:43:14,266 --> 00:43:16,100 seems to have made Andean flickers 564 00:43:16,100 --> 00:43:19,866 more eager than other woodpeckers for a social life. 565 00:43:21,666 --> 00:43:24,333 ♪♪ 566 00:43:24,333 --> 00:43:27,433 They even nest in small colonies 567 00:43:27,433 --> 00:43:29,966 with maybe a dozen birds 568 00:43:29,966 --> 00:43:32,566 sharing a cliff in close proximity. 569 00:43:35,400 --> 00:43:37,833 They also tolerate a small neighbor eager 570 00:43:37,833 --> 00:43:39,933 to use their nest holes, too. 571 00:43:44,166 --> 00:43:45,866 Blue-and-white swallows 572 00:43:45,866 --> 00:43:48,766 like the same high-altitude grasslands, 573 00:43:48,766 --> 00:43:50,200 though they forage in the air 574 00:43:50,200 --> 00:43:54,833 and don't compete with the flickers for food. 575 00:43:54,833 --> 00:43:58,000 And their busy chatter adds life to the little village 576 00:43:58,000 --> 00:44:01,466 on the cliffs of the flickers' high frontier. 577 00:44:01,466 --> 00:44:03,900 [ Chirping ] 578 00:44:03,900 --> 00:44:07,266 ♪♪ 579 00:44:10,400 --> 00:44:14,166 The social scene is much more intense back in the oak trees 580 00:44:14,166 --> 00:44:15,766 of California. 581 00:44:19,033 --> 00:44:23,100 As nesting season comes around, the family life of Acorn woodies 582 00:44:23,100 --> 00:44:25,333 becomes more cooperative, 583 00:44:25,333 --> 00:44:29,633 more competitive, and more complex than ever. 584 00:44:32,000 --> 00:44:33,933 In every family group, 585 00:44:33,933 --> 00:44:37,500 there may be three or four females that breed... 586 00:44:37,500 --> 00:44:40,500 and three or four males that breed, too. 587 00:44:42,666 --> 00:44:45,433 The males are distinguished by white foreheads 588 00:44:45,433 --> 00:44:47,400 and bright red crowns. 589 00:44:50,000 --> 00:44:52,600 The females also have white foreheads, 590 00:44:52,600 --> 00:44:55,900 but their crowns are black and red. 591 00:44:55,900 --> 00:44:57,900 [ Squawking ] 592 00:45:00,833 --> 00:45:04,100 These breeding birds all mate with each other, 593 00:45:04,100 --> 00:45:06,800 but never stray outside the group. 594 00:45:09,866 --> 00:45:12,133 The rest of the family are helpers, 595 00:45:12,133 --> 00:45:15,666 older siblings waiting to move up to breeding status. 596 00:45:25,333 --> 00:45:28,566 The females manage to sync their breeding 597 00:45:28,566 --> 00:45:33,200 to lay their eggs at the same time. 598 00:45:33,200 --> 00:45:35,233 They all use the same nest 599 00:45:35,233 --> 00:45:38,466 and take turns incubating the group's eggs. 600 00:45:41,766 --> 00:45:46,300 But it's a male's duty to tend the eggs through the night, 601 00:45:46,300 --> 00:45:49,000 and whether this one's a father or not, 602 00:45:49,000 --> 00:45:52,466 he's come to take over... 603 00:45:52,466 --> 00:45:54,966 and settles down in the dark. 604 00:45:58,966 --> 00:46:01,733 Soon enough, the family is hard at work. 605 00:46:05,366 --> 00:46:07,333 Not every egg hatches, 606 00:46:07,333 --> 00:46:12,633 but the family now has three chicks to raise. 607 00:46:12,633 --> 00:46:15,133 The chicks are naked and blind, 608 00:46:15,133 --> 00:46:16,733 but they're loud... 609 00:46:16,733 --> 00:46:19,533 [ Chicks chirping ] 610 00:46:19,533 --> 00:46:23,066 ...and quick to respond when an adult comes with food. 611 00:46:31,033 --> 00:46:35,666 Now the ready supply of acorns really pays off. 612 00:46:35,666 --> 00:46:39,100 The chicks can start out on nutritious acorn mash 613 00:46:39,100 --> 00:46:41,033 and never go hungry. 614 00:46:51,233 --> 00:46:56,033 In just 18 days, they're sprouting long, dark feathers. 615 00:46:59,700 --> 00:47:02,933 Soon, they develop their first crown plumage, 616 00:47:02,933 --> 00:47:05,366 and they all appear to be male. 617 00:47:05,366 --> 00:47:07,600 Except...they're not. 618 00:47:10,533 --> 00:47:12,866 All Acorn chicks wear male plumage 619 00:47:12,866 --> 00:47:15,066 until their first winter. 620 00:47:15,066 --> 00:47:17,700 No one knows why. 621 00:47:17,700 --> 00:47:22,200 ♪♪ 622 00:47:22,200 --> 00:47:25,800 At every feeding, each chick wants all the attention. 623 00:47:30,666 --> 00:47:32,900 But they're all getting plenty of food. 624 00:47:36,900 --> 00:47:41,433 Every adult in the group -- the mothers, the fathers, 625 00:47:41,433 --> 00:47:45,100 all the helping aunts, brothers, uncles, and sisters -- 626 00:47:45,100 --> 00:47:48,166 is bringing them a constant supply. 627 00:47:48,166 --> 00:47:54,933 ♪♪ 628 00:47:54,933 --> 00:48:01,800 ♪♪ 629 00:48:06,566 --> 00:48:10,666 But one female has her own agenda. 630 00:48:10,666 --> 00:48:14,166 Somehow, she's well out of sync with the other females 631 00:48:14,166 --> 00:48:18,233 and drops into the nest now to start laying eggs -- 632 00:48:18,233 --> 00:48:20,500 right in the middle of the mayhem! 633 00:48:24,733 --> 00:48:29,833 The female tries over and over to incubate the new eggs, 634 00:48:29,833 --> 00:48:32,133 but it's no use. 635 00:48:32,133 --> 00:48:34,500 These eggs will never hatch. 636 00:48:37,400 --> 00:48:38,933 But the chicks are doing well 637 00:48:38,933 --> 00:48:41,400 under all the relentless parenting. 638 00:48:45,733 --> 00:48:48,800 It's been just three weeks since they hatched. 639 00:48:48,800 --> 00:48:51,233 Now the adults stop entering the nest 640 00:48:51,233 --> 00:48:54,366 and encourage the youngsters to climb to the hole. 641 00:48:57,333 --> 00:49:05,466 ♪♪ 642 00:49:05,466 --> 00:49:07,633 Though this little woodpecker is so eager 643 00:49:07,633 --> 00:49:10,233 to look out on an exciting world, 644 00:49:10,233 --> 00:49:15,366 he can have no idea what changes are on their way to his valley. 645 00:49:19,533 --> 00:49:23,033 Ready or not, he's launching into it. 646 00:49:23,033 --> 00:49:28,633 ♪♪ 647 00:49:28,633 --> 00:49:34,200 ♪♪ 648 00:49:34,200 --> 00:49:37,900 Every spring, a new class of young woodpeckers graduates 649 00:49:37,900 --> 00:49:42,166 from their nest holes to take on the challenge of growing up. 650 00:49:42,166 --> 00:49:47,633 ♪♪ 651 00:49:47,633 --> 00:49:50,433 Their abilities will surely be tested under the stress 652 00:49:50,433 --> 00:49:54,166 of rising temperatures and unpredictable weather. 653 00:49:56,333 --> 00:50:00,100 Some forests will be parched for water. 654 00:50:00,100 --> 00:50:02,133 [ Thunder crashes ] 655 00:50:02,133 --> 00:50:04,400 Others will have too much. 656 00:50:04,400 --> 00:50:10,033 ♪♪ 657 00:50:10,033 --> 00:50:13,566 Already, trees and insects are on the move. 658 00:50:16,800 --> 00:50:18,966 But woodpeckers have skills honed 659 00:50:18,966 --> 00:50:22,400 over many millions of years. 660 00:50:22,400 --> 00:50:25,200 They will not be caught standing still. 661 00:50:25,200 --> 00:50:33,766 ♪♪ 662 00:50:33,766 --> 00:50:36,900 Bright and beautiful Red-bellied woodpeckers 663 00:50:36,900 --> 00:50:42,633 have been steadily moving north for some 70 years. 664 00:50:42,633 --> 00:50:44,400 Historically, they were residents 665 00:50:44,400 --> 00:50:46,633 of the American Southeast, 666 00:50:46,633 --> 00:50:49,766 only rarely seen north of the New York border. 667 00:50:49,766 --> 00:50:56,933 ♪♪ 668 00:50:56,933 --> 00:51:02,000 But by 1980, Red-bellies were nesting around Boston 669 00:51:02,000 --> 00:51:04,066 and the southern Great Lakes. 670 00:51:04,066 --> 00:51:09,766 ♪♪ 671 00:51:09,766 --> 00:51:12,766 As the millennium dawned 20 years later, 672 00:51:12,766 --> 00:51:18,533 they had crossed into Canada, from Quebec to central Ontario. 673 00:51:18,533 --> 00:51:23,966 ♪♪ 674 00:51:23,966 --> 00:51:27,933 [ Calling ] 675 00:51:27,933 --> 00:51:30,800 Today, these woodpeckers-on-the-move 676 00:51:30,800 --> 00:51:34,133 are continuing their conquest of the North, 677 00:51:34,133 --> 00:51:37,500 a range expansion of a thousand miles. 678 00:51:37,500 --> 00:51:40,800 [ Calling ] 679 00:51:40,800 --> 00:51:47,366 ♪♪ 680 00:51:47,366 --> 00:51:50,400 A warming world is a boon to them... 681 00:51:50,400 --> 00:51:52,733 and they have seized the moment. 682 00:51:52,733 --> 00:52:02,633 ♪♪ 683 00:52:02,633 --> 00:52:04,566 For every coming change, 684 00:52:04,566 --> 00:52:08,700 there will be winners and losers. 685 00:52:08,700 --> 00:52:12,233 And as woodpeckers everywhere face the future, 686 00:52:12,233 --> 00:52:15,466 may their resilience and innovative homes 687 00:52:15,466 --> 00:52:18,500 help secure their survival. 688 00:52:25,400 --> 00:52:34,533 ♪♪ 689 00:52:34,533 --> 00:52:44,533 ♪♪ 690 00:52:44,533 --> 00:52:54,533 ♪♪ 691 00:52:54,533 --> 00:52:57,800 ♪♪ 692 00:52:57,800 --> 00:53:01,266 To learn more about what you've seen on this "Nature" program, 693 00:53:01,266 --> 00:53:03,200 visit pbs.org. 694 00:53:03,200 --> 00:53:12,900 ♪♪