NEW YORK -- From Christopher Columbus to Marco Polo, human explorers throughout history have traveled far distances. But some of the world's greatest explorers are in the animal kingdom.
NatGeo's new series, "Incredible Animal Journeys," follows the migration of animals both big and small, often with their young, all around the world.
"We humans think we are the great explorers of the Earth, but we would be lost without a map," Showrunner Sarah Gibbs said. "The real heroes are those in the animal kingdom who make these incredible journeys."
The documentary, filmed over three years and spanned seven continents, follows some of the harrowing and heartwarming journeys animals tame across the globe.
The team managed to capture a humpback whale giving birth -- a feat so rare the producers called it the "holy grail." The crew went on to follow the whale as she shepherded her tiny newborn calf from Hawaii to Alaska.
"The material that Sarah and the team captured blew me away. We have world first, after world first," Executive Producer Mark Brownlow said. "From humpback whale mothers giving birth on camera for the first time, I mean this is the holy grail, to moments that just make you weep with emotion."
"Getting that birth is really tough so you have to be in the right place at the right time and be really patient," Gibbs said.
A barn swallow with the will to survive and fly thousands of miles is particularly inspirational.
"A tiny bird the size of your hand who will travel 6,000 miles from South Africa to the UK to reunite with her love," Gibbs said.
One particularly sad moment, because nature and human interference can be particularly cruel, a whale is helped by another traveler to take its last breaths, after having been caught in fishing gear.
"It pushed away the tiger sharks to assist her in her final breaths," Brownlow said.
"It gives me hope that you can see that kindness and compassion in the animal world and we need more of that in our lives, we need to be kinder to each other, we need a sense of perspective and to see the world for what it is, which is an incredible, amazing place," Gibbs said.
A highlight of the series is the narration by actor Jeremy Renner. He suffered a devastating accident last January when he was critically injured after he was run over by his snowplow.
He's made an amazing recovery, and during the process, provided the voiceover for the series. Which was in itself an emotional journey for the actor as well.
"We all have our own journeys and Jeremy certainly had been on a real journey and a journey of recovery and it was a real privilege to work with him as he was kind of coming back to work," Gibbs said. "He's kind of reading the script and you can kind of see how he's affected by these stories because they're really emotional."
"It's true to say, and I don't think Jeremy will mind us saying that there were times that he was choked with emotion just as he lived and breathed because the incredible journeys that our wild heroes undertake, but he was such a natural and so embedded in the series and committed to it," Brownlow said.
You can stream "Incredible Animal Journeys" starting on Nov. 19, on National Geographic and the following day on Hulu and Disney+.
Disney is the parent company of NatGeo, Hulu, Disney+ and this station