Despite the intense heat, a female hummingbird must adapt her diet and work non-stop to feed the young in her nest. The rattlesnakes are breeding, and the victorious male claims its hard-won mate.

Male rattlesnakes “dance” in a show of strength designed to win females. A cholla cactus uses its prickly form of defense and the passing javelina to populate new parts of the desert. Meanwhile, the javelina’s tiny young are threatened by a hungry coyote.

A courageous roadrunner faces off with a venomous rattlesnake. The small amount of precious rainfall that January provides gives the desert a sudden spark of life. Plants grow, flower, and store water, and the tiny Costa’s hummingbird uses the finest materials that nature provides to make a nest for her young.

Arizona’s Saguaro National Park was created to save the iconic and increasingly rare saguaro cactus from extinction. Within the park’s desert scenery, conflicts arise between species and can often resemble an Old West showdown at high noon!

Yosemite’s mountain peaks are already capped with snow and a mist rolls through the valleys. The coyote’s mating season begins as winter starts, and the bobcat mother will soon leave her young to fend for themselves.

Yosemite’s trees and animals have adapted to endure the occasional wildfire and the extreme changing of the seasons. In September, marmots prepare their burrows for hibernation and the deer are full of energy as the annual rut approaches.

In the lower valley, a foraging black bear attacks a colony of ants, which quickly rally to defend themselves. At its driest in summer and fall, the park is at the mercy of forest fires. One of the largest ever, the Rim Fire, broke out in the autumn of 2013, and burned out of control for over ten weeks.

It’s June, and Yosemite has come alive with noise and vibrant colors. The meadow flowers are in bloom, the bobcat kittens are almost full-grown, and the park’s unique amphibian and rodent populations emerge from their winter rest.

The imposing rock faces of Yosemite are very popular with sport climbers, and the rocky heights are also home to the endearing American pika. Mule deer, many with fawns, inhabit the lower valley, which is awash with spring color.

In the wooded valley, a pine squirrel falls prey to the voracious bobcat. Here we find some of the oldest and tallest trees on earth: The giant sequoias, which are now a major attraction for visitors to the park.

A relaxing bobcat family is surprised by the appearance of a young black bear. Elsewhere, a raven family is threatened by the presence of a bald eagle circling above their nesting site.

Molten granite was cooled and scoured by glaciers, forming Yosemite’s almost surreal landscape with its many remarkable rock formations. Black bears inhabit the park and emerge each spring from their hibernation, ready to begin a new cycle of life.

As spring arrives, the remarkable and deadly poisonous Sierra newt moves to its traditional aquatic breeding grounds. Meanwhile, kingfishers fish the crystal clear Yosemite streams and squirrels play a dangerous game of chase with the hunting bobcats.

Protected by presidential decree, the breathtaking mountainous terrain of the Yosemite Valley is now a national park, enjoyed by many human visitors, while still home to the wild creatures and stunning vegetation that has inhabited it for millennia / centuries.

Sigrid talks about the reality of conversing with someone who has Alzheimer's. They often have trouble finding the word for the thing they are thinking of.